**Abstract**

Socioeconomic status is the totality of an individual's social and economic conditions and may vary from person to person based on various criteria, issues, and distinct factors. A family's socioeconomic status is based on family income, parental education level, parental occupation, and social status in society. This study intends to determine student's socioeconomic status and explain how it affects mental health, academic performance, and personal life among university students. This is a mixed-method study, with both qualitative and quantitative methods. The study data and information were collected from the students of Jatiya Kabi Kazi Nazrul Islam University, Mymensingh, Bangladesh. The study sample size is 180 (n=180; male = 81 and female = 99; including case study= 05) The sample was collected through a convenient sampling method, and a face-to-face interview was conducted. The male (72.7%) and female (66.7%) students are more mentally stressed by socioeconomic status, and above half of the respondents' (55%) academic study is influenced by it. Overall, this analytical study will also progressively contribute to getting the whole idea about the socioeconomic status of the university students in Bangladesh.

**Keywords:** socioeconomic status, mental health, academic performance, university students, Bangladesh


**15. Aluminium (or aluminum) and ceramics**

tween the fibers of the interface and the middle strata intra- and extracellular silicone drop‐ lets and bulks were observed, representing the location where further pathological processes can take place [205]. It is said by Dr. Sidney Wolfe, director of Public Citizen's Health Research Group, in a statement that: "Public Citizen continues to oppose the FDA's 2006 decision to return silicone breast implants to the market for cosmetic use in women for augmentation. The agency's newer information about the risk of implant-associated lym‐ phoma and the previously known risks are serious enough to warrant advising women

On March 9, 2012 a new silicone breast implant, which joins the two other silicone breast implants on the market - one made by Allergan and the other by Mentor, was approved by the FDA of the United States of America. Recommended monitoring after initially silicone breast implantation is 3 years and then every two years thereafter. In a review Roach and coworkers concern the importance of length and time on physicochemical interactions be‐ tween living tissue and biomaterials that occur on implantation. The review provides de‐ tailed information on material host interactions, dynamic material/cell surface states, surface chemistry and topological roles during the first stage of implant integration, namely protein adsorption. Generally, after the first contact of material with host tissue a state of flux due to protein adsorption, cell adhesion and physical and chemical alteration of the implanted ma‐ terial is followed (Figure 10) [206]. This model can answer many questions concerning the conformational form and bound proteins and therefore has instruction meanings in new im‐

**Figure 10.** Schematic of protein–surface interactions: Chemistry—adsorption onto biotinylated stripes which appear white, whilst adsorption is hindered on square oligoethylene-glycol regions, the white box shows an intentionally bleached area Topography—albumin adsorption onto hydrophilic silica spheres of varying dimensions as a model of

against having these implanted."

134 Advances in Biomaterials Science and Biomedical Applications

plantable biomaterial design field.

surface curvature [206].

Aluminium (or aluminum) is the third most abundant chemical element (after oxygen and silicon in the boron group) with symbol Al and atomic number 13. It is one of the typical metals which has been widely used as hard tissue repair materials with unique properties, such as strong mechanical strength, not soluble and degradable in body fluid under normal circumstances, combined in over 270 different minerals, low density (weight) and corrosion resistances [211]. It is generally accepted that metallic implant materials with higher strength/modulus ratios are more favorable for hard tissue repair due to a combined effect of high strength and reduced stress-shielding risk [212].

Al alloys, such as Al-silicon (Si), Al-platinum, and Al-titanium (Ti) are widely used in im‐ plantable engineering structures and components where light weight or corrosion resistance is required except for blood-contacting surfaces [213,214]. For example, an implantable dou‐ ble-sided electrode microdevices, called flexible nerve plates, with a prototype of Al layer could reduce the number of insertion sites and thereby the insertion trauma during implan‐ tation of neural prostheses [215]. A Ti-6Al-4vanadium (V) alloy was selected as the ceramicto-metal seal because its excellent mechanical properties and favorable biocompatibility [216]. The first-generation of implantable left ventricular assist devices (LVADs) were Ti-Alvanadium alloy pulsatile, volume-displacement pumps. The modern LVAD era began with the introduction of the HeartMate X (vented electric) VE in 1998 [217]. These devices can provide excellent circulatory support and improve survival until heart transplantation. However, they have many application limitations, such as a large volume, an excessive sur‐ gical dissection, a large diameter driveline, a noisy pump operation, and particularly a limit‐ ed mechanical durability. Other complications include bleeding, infections and thromboembolic events. During the succeeding decade, vast improvements in pump design resulted in a new crop of LVADs, whose attributes are transforming LVAD therapy into a kind of standard of care for end-stage heart failure [218]. LVAD therapy has now evolved into a solution which is strikingly superior to optimal medical therapy [219, 220].

It was reported that changes in the porous hydroxyapatite and Al oxide orbital implant den‐ sities may correspond to healing and maturation of soft tissues surrounding and penetrating the implants [221]. The thermal oxidation behavior of Al ion implanted Ti nitride films has been studied in dry oxygen atmosphere and found that Al implantation caused the oxida‐ tion rate of TiN films to slow down at the initial stage of oxidation [222]. Until recently, there is limited evidence regarding comparative effectiveness of various hip implant bear‐ ings, especially metal on metal or ceramic on ceramic implants compared with traditional metal on polyethylene or ceramic on polyethylene bearings [223].

For clinical applications, it is an important character that the metal devices do not cause mental or body uncomfortable reactions, such as delaminate or infiltrate ions to the sur‐ round tissues. For example, a defibrillator is a medical device that generates and delivers a shock to the heart of someone in cardiac arrest. Although this device can save lives, there are risks involved, for both the patient and the first responders. One risk associated with defib‐ rillator use is that of burns. Certain transdermal medication patches contain aluminum back‐ ings, and when they come in contact with the defibrillator paddle, can cause minor burns to the patient. Accidental shocks to others can occur when first responders accidentally contact with the patient who is being defibrillated. The only objects that should touch the patient during treatment are the defibrillator paddles held by the administrator of the procedure. Sometimes internally implanted defibrillators discharge shocks when they are unnecessary. When this occurs, it can cause pain and promote a dangerous heart rhythm. In addition, the event can be emotionally disturbing and frightening. Doctor can recalibrate the device to minimize the risk of additional unnecessary shocks, and offer suggestions on how to man‐ age these rare events [224].

A ceramic is an inorganic, nonmetallic solid material possessing strong mechanical proper‐ ties prepared by the action of heat and subsequent cooling [30]. The uses of ceramics have been revolutionizing the biomedical field in deployment as implants for humans during the past three decades. In the search to improve the biocompatibility and mechanical strength of skeletal implant materials, attention has been directed towards the potential use of ceramic composites [225]. Since 1975 alumina ceramic has proven its bioinertness and have been ac‐ cepted in biomedical applications, some alumina ceramic, such as Al2O3 has been character‐ ized with high hardness and high abrasion resistance. Noiri and coworkers evaluated the biocompatibility of alumina-ceramic material histopathalogically for eight weeks by im‐ planting in the eye sockets of albino rabbits with no signs of implant rejection or prolapse of the implanted pieces. After a period of four weeks of implantation, fibroblast proliferation and vascular invasion were noted. By the eighth week, tissue growth was observed in the pores of the implants [226].

vanadium alloy pulsatile, volume-displacement pumps. The modern LVAD era began with the introduction of the HeartMate X (vented electric) VE in 1998 [217]. These devices can provide excellent circulatory support and improve survival until heart transplantation. However, they have many application limitations, such as a large volume, an excessive sur‐ gical dissection, a large diameter driveline, a noisy pump operation, and particularly a limit‐ ed mechanical durability. Other complications include bleeding, infections and thromboembolic events. During the succeeding decade, vast improvements in pump design resulted in a new crop of LVADs, whose attributes are transforming LVAD therapy into a kind of standard of care for end-stage heart failure [218]. LVAD therapy has now evolved

It was reported that changes in the porous hydroxyapatite and Al oxide orbital implant den‐ sities may correspond to healing and maturation of soft tissues surrounding and penetrating the implants [221]. The thermal oxidation behavior of Al ion implanted Ti nitride films has been studied in dry oxygen atmosphere and found that Al implantation caused the oxida‐ tion rate of TiN films to slow down at the initial stage of oxidation [222]. Until recently, there is limited evidence regarding comparative effectiveness of various hip implant bear‐ ings, especially metal on metal or ceramic on ceramic implants compared with traditional

For clinical applications, it is an important character that the metal devices do not cause mental or body uncomfortable reactions, such as delaminate or infiltrate ions to the sur‐ round tissues. For example, a defibrillator is a medical device that generates and delivers a shock to the heart of someone in cardiac arrest. Although this device can save lives, there are risks involved, for both the patient and the first responders. One risk associated with defib‐ rillator use is that of burns. Certain transdermal medication patches contain aluminum back‐ ings, and when they come in contact with the defibrillator paddle, can cause minor burns to the patient. Accidental shocks to others can occur when first responders accidentally contact with the patient who is being defibrillated. The only objects that should touch the patient during treatment are the defibrillator paddles held by the administrator of the procedure. Sometimes internally implanted defibrillators discharge shocks when they are unnecessary. When this occurs, it can cause pain and promote a dangerous heart rhythm. In addition, the event can be emotionally disturbing and frightening. Doctor can recalibrate the device to minimize the risk of additional unnecessary shocks, and offer suggestions on how to man‐

A ceramic is an inorganic, nonmetallic solid material possessing strong mechanical proper‐ ties prepared by the action of heat and subsequent cooling [30]. The uses of ceramics have been revolutionizing the biomedical field in deployment as implants for humans during the past three decades. In the search to improve the biocompatibility and mechanical strength of skeletal implant materials, attention has been directed towards the potential use of ceramic composites [225]. Since 1975 alumina ceramic has proven its bioinertness and have been ac‐ cepted in biomedical applications, some alumina ceramic, such as Al2O3 has been character‐ ized with high hardness and high abrasion resistance. Noiri and coworkers evaluated the biocompatibility of alumina-ceramic material histopathalogically for eight weeks by im‐

into a solution which is strikingly superior to optimal medical therapy [219, 220].

metal on polyethylene or ceramic on polyethylene bearings [223].

136 Advances in Biomaterials Science and Biomedical Applications

age these rare events [224].

**Figure 11.** Scanning electron microscopy (SEM) images of SaOS-2 cells cultured for 48 h on micropatterned Ti (A-D) and diamond-like carbon (DLC) (E, F) surfaces. Large-sized (125 µm) squared (A) and circular (B) features facilitated the adhesion of several cells on one Ti island with the cells aligning themselves along the edges of the cell-friendly materi‐ al. The cells adhering to mediumsized Ti islands no longer conformed strictly to the geometrical shape of the patterns (C) but particularly on circularly patterned surfaces, star-like cellular morphologies appeared (D). On small-sized in‐ verse DLC samples, the cell bodies non-selectively covered large micro-patterned areas (E), but their filopodia clearly showed a preference for DLC trying to avoid bare Si circles (F) [222].


**9. Conclusions**

In the literature, many core-losses models are available to select. Researchers continue developing new core losses models with specific features (core material, waveform, density flux, application, frequency range, among others), but the majority are not easy to replicate.

To develop a power core losses model that involves electrical, magnetic, thermal effects, suitable for all kinds of ferromagnetic materials, and also competent to power electronic is fundamental. Not only for advantages to calculate power core losses accurately but not to reach optimal magnetic components. The challenge is to understand the comportment of

the magnetic materials and model them differently than ferrite magnetic elements because, until now, both are very similar, although their behaviour is quite different.

Each of the core losses models in this document is a point of start for researchers. Despite promising results using Steinmetz's equations, those are not enough to calculate the core losses accuracy according to the need for the power electronic community. FEM software is indispensable nowadays to validate the power losses model as the magnetic component design. At the same time, virtual laboratories are promising to be the trend in a few years, allowing a reduction of the cost of a physical test bench to that of a virtual one and getting good approximations of the magnetic component behavior in a real environment. In addition, the option to interconnect different kinds of software to implement complete power electronics systems in platforms such as HIL, SIL, and MIL, makes the capability of design more versatile.

**Author Contributions:** Conceptualization, D.R.-S. and F.J.P.-P.; methodology, M.A.R.-L.; software, I.A.-V.; validation, J.P.-O., A.-I.B.-G. and F.J.P.-P.; formal analysis, M.A.R.-L.; investigation, D.R.-S.; resources, F.J.P.-P. and A.-I.B.-G.; data curation, J.P.-O.; writing original draft preparation, D.R.-S.; writing—review and editing, D.R.-S., M.A.R.-L., J.P.-O. and F.J.P.-P.; visualization, D.R.-S.; supervision, I.A.-V.; project administration, A.-I.B.-G.; funding acquisition, F.J.P.-P. and I.A.-V. All authors have read and agreed to the published version of the manuscript.

**Funding:** The authors thank Tecnológico Nacional de México, Instituto Tecnológico de Celaya. The work of Daniela Rodriguez-Sotelo was supported by CONACYT through a Ph.D. grant.

**Acknowledgments:** The authors thank IPN, Tecnológico Nacional de México, Instituto Tecnológico de Celaya and CONACYT.

**Conflicts of Interest:** The authors declare no conflict of interest.


**3.1 Indoor air pollution**

There are many sources of indoor air pollution, which can be increase with outdoor pollutions contaminant. Exposure to indoor air pollutants can cause detrimental health issues, which could cause minor symptoms such as allergies represented with constant sneezing, coughing which can be exacerbated with indoor change in temperatures and irritants [17]. This irritant could cause only upper respiratory symptoms; however, it could get complicated with lower respiratory symptoms such as reactive airway disease and bronchial asthma exacerbations in patients with underlying hyperactive airways. It's important to note that indoor environments will get outdoor mixtures of pollutants in which will reaccumulate with indoor sources causing a conjoined effect. Indoor factors could range from animal matters, molds from humid areas, secondhand tobacco exposure and dust mites among others that will be further discuss.

### **3.2 Particulate matter**

It consists of particles suspended in the air which can be from human sources such as factories, vehicles, personal or community transports, electricity plants and industrial fumes, or natural matters such as pollen, spontaneous fires, spores, animal debris and

*Environmental and Occupational Factors; Contribution and Perspectives on Difficult to Treat… DOI: http://dx.doi.org/10.5772/intechopen.108605*

plants among others. It's important to note that particulate matter can be divided with sizes going from particles less than 10 um in diameter (PM10) to particles less than 2.5 um (PM2.5) [18]. One of the strongest clinical differences between this particle is that particles less than 10 um could enter the respiratory system, and the smallest ones will be able to enter the alveoli which is the distal component of the airway. Particles that are between 2.5 um to 10 um will not be able to reach the alveoli but will be possible to deposit in the more proximal airways in which the clinical sequela will be different. With this it's important to point out that proximal airway deposition will have a clinical presentation of asthma, with reactive airway disease, which may cause inflammation and subsequent exacerbation of underlying asthma. Multiple studies have shown that strong particulate exposure led to lower pulmonary function and deterioration overtime [19]. Physiology of particulate matter starts when it enters the body through the nose and mouth when we are breathing, at that moment the body will be able to eliminate most of the largest particles which are the ones more than 2.5 um, but the other smaller particles will continue passage into the lungs and have detrimental stationary inflammatory effects in the alveoli. This effect could lead to interstitial lung disease with permanent parenchyma damage as well acute diseases such as hypersensitivity pneumonitis, chronic bronchitis among others [20]. It will not only lead to respiratory symptoms if can case cardiovascular complications such as arrhythmia and coronary artery disease. This makes particulate matter a detrimental environmental factor to the healthy people but most importantly to patients with comorbidities such as asthma.

### **3.3 Indoor nitrogen dioxide**

Nitrogen dioxide is an irritant gas that has strongly been linked with respiratory symptoms with negative long term sequelas. It's a product of elevated temperature combustion as can been seen in indoor gasses such as indoor stoves. There are other sources of NO2 such as power plants which is specifically important in low-income countries with poor power supply, as well diesel power construction machines and industrial machines. It's important to note that even though most of the NO2 sources are from the outdoors, this outdoors contaminants could penetrate inside houses and became constant irritants to the households, making patients with pulmonary diseases more vulnerable [21]. Severe health effects of NO2 exposures would affect proximal airway causing worsened of cough with wheezes, causing increased in asthma exacerbations, leading to more hospital admissions. Constant exposure will eventually cause increased airway inflammation with remodeling of the airway, making it more severe with time. This patient will be escalating asthma treatments quickly without major relief and eventually will ne on advanced asthma treatments of this exposures are not recognized. There are multiple scientific studies that link decreased in pulmonary function such as diminished peak flows with higher exposure of N02. Avoidance and early recognition of improperly used heating devices and combustion devices is of greatest importance for avoidance [22]. Special attention to poorly vented placed, in which combustion products are been produced such as Nitrogen dioxide (NO2), carbon monoxide, Sulfur dioxide (SO2) and particulate matter as previously mentioned is key on the management of this patients.

#### **3.4 Dust mites**

Dust Mites are a worldwide problem in respiratory vulnerable patients. This are tiny organism that live in furniture's such as beddings, bed, soft toys, and clothing

most of the time at people's homes. This organism is not airborne they live in soft and humid environments [23]. Dust mites most of the time become airborne with cleaning activities such as vacuum and dusting which organism will be mobilized and as other particulate matter react to nasal receptors and start the perpetuating sequela. Dust mite allergies can be detected with blood samples, for better preventive measures which the goal when recognizing exacerbating factors. Other preventive measures that will be discussed is the use of allergen proof mattress with pillowcases, close washing of bedding in a weakly basis, carpets and rugs management with high efficiency particulate air filter. The physiology of symptoms starts with indoor mites that are constantly feeding from death skin, that eventually will liberate allergens during that chemical process that will eventually lead to an asthma trigger, that most of the time will start with upper airway symptoms, with eventual bronchospasm due to airway hyperresponsiveness. It's important to recognize Dust mites because it's a strong allergen, difficult to take care of, and take meticulous weekly indoor management protocols for prevention of exacerbations. Asthma medications can help ameliorate dust mite reaction, but preventive measures with bedding cleaning, keeping beds with dust proof covers as well warm cleaning with higher degree temperature is the recommended range for adequate cleaning [24].


**2. Precursor lesions of cervical carcinoma**

Precursor lesions of both squamous cell carcinoma and adenocarcinoma are well defined, according to our current understanding of cervical neoplasia. However, years of scientific observations and research preceded the recognition of these lesions. Observations concerning spatial and/or temporal relationship between invasive carcinomas and non-invasive, intrae‐ pithelial alterations of the uterine cervix had been repeatedly reported in the past, as early as the end of the 19th century [24-27]. These observations resulted in the recognition of precan‐ cerous alterations of cervical epithelium, for which different terms and definitions have been used in the following years.

The terms carcinoma in situ and dysplasia have been in use for several decades, in order to describe non-invasive, intraepithelial lesions showing cytologic abnormalities akin to those of invasive carcinoma. In the late 1960's the concept of one disease spectrum was introduced, based on observed similarities between groups of lesions, which were considered as different grades of the same disease process, termed cervical intraepithelial neoplasia / CIN [28,29]. This terminology became the most widely used for the next decades and is currently in use in many laboratories worldwide.

The recognition of the important role[s] of human papillomavirus in cervical carcinogenesis gradually led to different approaches, concerning the whole group of HPV-related lesions and their classification, based on more recent biologic and molecular data [11,13,30,31]. Among them the distinction between two basic biological entities was included: specifically, between a productive viral infection and an intraepithelial neoplastic process. Several questions remain to be answered; however, on a practical level, patient management remains an important basis that influences and often guides choices of terminology.

In the last decades a binary system of classification based on The Bethesda System [TBS] has been mainly in use by cytopathologists; however, several histopathology laboratories world‐ wide have also adopted similar terminology. A binary system is more consistent with the current knowledge concerning HPV-related disease and is considered to form a basis for improved communication between gynaecologists and pathologists [31]. Moreover, the intermediate group (IN2) has not been shown to comprise a reproducible diagnostic category among pathologists.


**Abstract**

Ameloblastoma is a benign odontogenic tumor of epithelial origin with locally aggressive behavior. It affects a broad age range of patients and it is most commonly found in the mandible, especially posterior area. The majority of ameloblastomas are conventional (multicystic), which are more difficult to eradicate than the unicystic or peripheral types. Although most of ameloblastoma cases can be treated predictably with radical surgical treatment, the management of recurrent and metastasizing ameloblastomas remains a major challenge. Surgical treatment is standard, but the extent of resection is controversial. Radical resection with segmental and marginal mandibulectomy or curettage and enucleation with better quality of life, but with higher recurrence rate. Besides the conventional surgical treatment, novel therapy options like neoadjuvant molecular targeted therapy and decompression in young patients could make a significant improvement in the management of the disease. The aim of this chapter was to determine the present and future concepts of treatment and discuss significant factors responsible for recurrence.

**Keywords:** ameloblastoma, odontogenic tumors, surgical procedures, molecular targeted therapy, recurrence


Although no exact approach has been developed for the target of zero balance during the design phase of ZEB, there are still some consensus and several common design elements for designing ZEB. A thorough design approach was proposed which involves 12 steps containing four foundational procedures, that is, applied metrics (e.g., primary energy, the cost), passive design (e.g., building envelope, orientation), active design (e.g., HVAC, lighting), and renewable energy system design (e.g., photovoltaic panel, wind turbine) for the design of ZEB [22, 23], as shown in **Figure 4**. Theoretically, design optimization of ZEB should be conducted considering the three vital design steps, that is, steps 7, 8, and 9, simultaneously to obtain a comprehensive combined design option for ZEB. Therefore, design optimization for ZEB is usually solved by integration of two or more software.

Passive design is an important procedure to reduce the building energy demand as much as possible. Then, high-efficiency active energy systems such as heating, cooling, and ventilation systems and lighting systems should be applied and improved together with high-performance control strategies; these could further reduce operational energy consumption in the building. Lastly, the feasibility of renewable energy technology should be assessed and selected as an on-site power supply system which works together with the power grid to reach the target of zero energy demand.

Various software tools have been developed to facilitate the selection of passive design, active design, and RES for buildings; several popular software are listed and compared in **Tables 2** and **3**. In ZEB design, the building energy demand can be firstly evaluated by using building energy simulation software such as EnergyPlus or TRNSYS. The selection of suitable renewable energy system for the building can then be conducted in software such as HOMER and TRNSYS. The design optimization software, HOMER, is developed by the US National Renewable Energy Laboratory (NREL) to assist in design optimization of hybrid energy systems for both grid-connected and autonomous building based on net present cost [24–27]. However, HOMER can only address a single-objective function for minimizing the net present cost, and it cannot solve multi-objective problems [28].

### **3.2 Performance evaluation criteria**

It is important to determine the evaluation criteria at the design stage. Various criteria have been proposed from a different perspective of users, which can be classified into four aspects covering technical and environmental issues, economic factors, and the interaction between building and grid, as shown in **Figure 5**.

#### **Figure 4.**

*The main steps to designing nZEB.*

**45**

design, RES) for ZEB.

*Definition and Design of Zero Energy Buildings DOI: http://dx.doi.org/10.5772/intechopen.80708*

Economical analysis

Technical analysis

Storage device

Thermal system

**Table 3.**

**Figure 5.**

Bioenergy √

Advantage User-friendly, easy

to understand, efficient graphical representation of results, hourly datahandling capacity

*Comparison of renewable energy simulation software [30].*

*The main four factors for evaluating ZEB performance.*

In terms of technological factors, recent researches have been focused on feasibility and/or reliability study of different technologies (passive design, active

for the building to achieve zero energy building for a particular region.

value, especially the cost and its payback period of installing on-site RES.

In terms of economic factors, ZEB users are more concerned about the economic

#### **Table 2.**

*Comparison of building energy consumption software [29].*

*Definition and Design of Zero Energy Buildings DOI: http://dx.doi.org/10.5772/intechopen.80708*

#### **Table 3.**

*Green Energy Advances*

**44**

**Figure 4.**

*The main steps to designing nZEB.*

In terms of technological factors, recent researches have been focused on feasibility and/or reliability study of different technologies (passive design, active design, RES) for ZEB.

In terms of economic factors, ZEB users are more concerned about the economic value, especially the cost and its payback period of installing on-site RES.

• Economic value [life cycle analysis (LCA), net present cost (NPC)]: The proposed renewable energy alternative will be assessed using one of the engineering economic techniques which are net present cost (NPC), life cycle analysis (LCA), benefit/cost analysis, and payback period.

In terms of environmental factors, the reduction of building load will definitely reduce the energy required from the grid and on-site RES size, which can be measured as pollutant emission.

• Pollutant emission: The criterion measures the equivalent emission of CO2, air emissions which are the results of applying different technologies in ZEB for a particular period.

In terms of grid interaction factors, the two-way electricity flow between building and grid poses more than technological challenges; those ZEB homeowners may make heavier use of the grid than the conventional building under one-way power flow. Grid interaction index is one of the indicators used to assess the grid stress caused by ZEB.

• Grid interaction index (GII): The criterion is defined as the standard deviation of the building-grid interaction over the specified time (e.g., 1 year). It is used to estimate the average stress of building on the grid, and a low standard deviation is preferred [28].

#### **3.3 Optimization method**

#### *3.3.1 Single-objective design optimization*

It is reported that there are more than 50% of design optimization problems that are addressed as single-objective optimization problems, and they are usually focused on the most important criteria such as economic cost or environmental issues. For designing ZEB, the optimization may be conducted by focusing on the only one aspect of ZEB performance, e.g., NPC and CO2 emissions. Besides, since multi-objective design optimization problems can also be transformed into singleobjective optimization problems by using weighting factor, it is reasonable to convert all of the concerned ZEB performance indices into one combined function, as shown in (Eq. (3)). Where X represents a vector of design variables at the design stage, fave and fi (i = 1, 2…n) are the combined objective and the normalized sub-objectives, respectively; wi is the corresponding weighting factor for each sub-objective:

$$\text{Min}\,f\_{an\epsilon} = \,^\|w\_1 \times f\_1(\mathbf{X}) \star w\_2 \times f\_2(\mathbf{X}) \star \dots \star w\_n \times f\_n(\mathbf{X})\tag{3}$$

$$\text{s.t.} AX \le a \tag{4}$$

$$g\_1(X) \quad \succeq 0 \tag{5}$$

$$\lg\_2(X) \tag{6}$$

**47**

**Figure 6.**

*Definition and Design of Zero Energy Buildings DOI: http://dx.doi.org/10.5772/intechopen.80708*

**3.4 Penalty cost for ZEB**

designed by designers.

*PC* =

**3.5 Individual ZEB or ZEB cluster**

optimization (PSO) is another favored method for optimal design of energy systems in

Although the progressive incentive policies have been recognized to widely encourage the installation of renewable energy system for buildings, the financial support scheme is forecasted to be downtrend and RES cost to be high, which are a barrier for promoting future buildings to be zero energy buildings. Therefore, a penalty cost scheme may be a good solution to build up the public's confidence and

A comparison of the building cost under different mismatch ratios is shown in **Figure 7**. It is found that the minimum total cost is supposed to be located in O1 under mismatch ratio less than 0, possibly between −1.0 and 0.0, indicating that the selection of design option under mismatch ratio of 1.0 is not cost-effective. However, the introduction of penalty cost can move the minimum cost from O1 to O2, or the higher mismatch ratio the less cost, depending on the type of penalty cost

The total cost (*TC*) of the building basically consists of the initial cost (*IC*) of RES (e.g., PV, WT) and the operation cost (*OC*) during the building usage stage due to the electricity consumption from grid and oil consumption (Eq. (4)). The penalty cost can be expressed as a mathematic expression, which is assumed to follow a segmented function, as shown in Eq. (5). It should be noted that the cost

*TCP* = *IC* + *OC* + *PC* (7)

*TC*1.0 × (*a* − α × *SF*),*SF* < *p*1

In recent years, wide ranges of researches are available on the topic of RES design/control for an off-grid building or a village in a remote area [25–27].

*TC*1.0 × (*c* − δ × *SF*),*SF* ≥ *p*2

*TC*1.0 × (*b* − β × *SF*),*p*1 ≤ *SF* < *p*2

. (8)

results may be greatly different according to the designed penalty cost:

⎧ ⎪ ⎨ ⎪ ⎩

*Single-/multi-objective design optimization using GA/NSGA-II.*

recent papers [33, 34]. A typical optimization process is shown in **Figure 6**.

encourage them to be actively involved in ZEB application.

#### *3.3.2 Multi-objective design optimization*

The design and operation of ZEB are actually integrated with building owners, environment, energy source, and smart grid; it is, therefore, a multi-objective design optimization problem with even contradicting objectives. In general, genetic algorithm (GA) is the most popular optimization approach for single-objective and multi-objective optimizations of energy systems in numerous studies [31, 32]. Besides, particle swarm

optimization (PSO) is another favored method for optimal design of energy systems in recent papers [33, 34]. A typical optimization process is shown in **Figure 6**.