The objective of this study was to compare the differences between males and females in the mediating effects of academic failure tolerance on the impact of self-efficacy on game addiction among adolescents. The results are summarized as follows. First, in both men and women, self-regulation, one of sub-variables of self-efficacy, had negative effects on game addiction. Second, in men, both emotion and behavior had negative effects on game addiction, while, in women, only behaviour did so. Third, among sub-variables of self-efficacy, in males, self-regulation and task difficulty had positive effects on academic failure tolerance, while, in women, self-regulation, confidence, and task difficulty did so. Fourth, testing the mediating role of academic failure tolerance in the effect of self-efficacy on game addiction showed that there was a partial mediating effect among males, while there was a perfect mediating effect among females. All this implies that there is a need to develop programs that help students maintain positive emotions and behaviors even after they have experienced academic failure, considering the importance of academic failure tolerance for students.

Introduction The term “coping”refers to the actions or thoughts that people use to deal with stressful encounters (Folkman, Lazarus, Gruen, & DeLongis, 1986). Coping strategies are adopted to change the stressed person-environment relationship by either confronting and/or by regulating the emotions (Lazarus & Folkman, 1987). Research focusing on coping mechanisms has been a prolific area of study, emerged from a wide range of disciplines including psychology, sociology, and anthropology. However, for marketing researchers, questions still remain about the issue of how coping strategies are manifested in everyday consumption contexts. This represents an important area of research in that consumer coping behavior can determine critical post-purchase outcomes such as re-patronage intention, repurchase intention, and word of mouth (Raghunathan & Pham, 1999). When a service failure occurs, consumers frequently experience negative emotions and make decisions under emotionally taxing conditions (Yi & Baumgartner, 2004). Numerous scholars have made attempts to understand various consumption-related emotions and subsequent conditions corresponding to them (e.g., Raghunathan & Pham, 1999; Richins, 1997; Sujan et al., 1999). However, despite the large volume of studies focusing on consumer emotions, very few studies have examined the relationships between negative emotions with consumer coping strategies (Yi & Baumgartner, 2004). With that in mind, the primary aim of this conceptual paper was to propose a model that delineates consumer coping mechanisms derived from negatives emotions in a service failure and recovery context. Conceptual Model Coping strategies are closely linked with an individual’s attempt to manage a given stressful environment (Lazarus, 1991). Lazarus and Folkman (1984) defined coping as “constantly changing cognitive and behavioral efforts to manage specific external and/or internal demands that are appraised as taxing or exceeding the resources of the person”(p. 141). Menaghan (1983, p. 159) defined coping efforts as “specific actions (covert or overt) taken in specific situations that are intended to reduce a given problem or stress.”Duhachek (2005) defined coping construct as “the set of cognitive and behavioral processes initiated by consumers in response to emotionally arousing, stress inducing interactions with the environment aimed at bringing forth more desirable emotional states and reduced levels of stress.”Thus, the key aspects of coping includes a consequence of emotion, a dynamic process, and behavior and emotional domains of consumer responses (Duhachek, 2005). Implicit in this conceptualization is the idea that links the emotions aroused from a particular circumstance, coping strategies, and subsequent behaviors. As shown in Figure 1, our conceptual model classifies a wide range of negative emotions generated by a service failure that are linked to a set of consumer coping strategies. This will in turn influence subsequent consumer post-purchase behaviors. The behaviors will be either retaliatory (vindictive WOM, brand switching, complaining) or conciliatory (positive WOM, re-patronage intention, repurchase intention) responses. Related Literature When an individual encounters a stressful event, different negative emotions are triggered according to one’s distinct appraisals of the situation (Lazarus, 1991). These appraisals, in turn, affect how the consumer responds to the situation emotionally and behaviorally. These emotions remain powerful until the emotion eliciting problems are resolved. Proposition 1. Cognitive appraisal of the service failure situation evokes negative emotions. While some studies use combined negative emotions to explain resultant consumer behavior, others suggest separate emotion inventories (Lerner & Keltner, 2001) as different emotions trigger huge variation in cognition. Consumer negative emotions that are associated with a service failure condition can be categorized into several subsets (Watson & Clark, 1992). Many studies have utilized a limited number of negative emotions to explain consumer behavior in a service failure context (Nguyen & McColl-Kennedy, 2003). Bonifield and Cole (2006) used an appraisal-tendency framework to predict the underlying mechanism of anger and regret, associated with consumers’appraisals about service failure and their effects on post-purchase behaviors. Yi and Baumgartner (2004) focused on four negative emotions of anger, disappointment, regret, and worry in a purchase context to investigate their linkages to consumer coping strategies. Further, Tronvoll (2011) identified a set of negative emotions experienced in unfavorable service experiences leading to consumer complaint such as shame, sadness, fear, anger, and frustration. Although some marketing theorists consider the emotion of frustration to be an overlap with anger, they can be distinct emotions, especially in the context of service failure, because blaming someone else is different from blaming no particular others (Roseman, 1991). Therefore, the subsequent behavior and adapting coping strategy may differ. Thus, this study distinguished frustration separated from anger. Building on the aforementioned research, this study identified five different categories of negative emotions that are frequently found in a purchase-related situation: anger, frustration, disappointment, regret, and anxiety. Anger associates with feeling of attacking someone or yelling, resulting from an individual to be blamed on of the situation (Lazarus, 1991). Frustration tends to occur when people attribute a goal incongruent event to situational factors (Roseman, 1991). Disappointment refers to the feeling occurred due to the outcome insufficient to meet the expectation (Ortony et al., 1988). Regret is evoked when alternative option seems to be better than the selected one (Zeelenberg et al., 1994). Anxiety is linked to uncontrollable circumstances that are not directly under the purview of the provider or the customer (Ruth, Brunel, & Otnes, 2002). Proposition 1-1. Consumer negative emotions associated with a service failure situation are categorized into anger, frustration, disappointment, regret, and anxiety. Appraisal theorists contend that people use different coping strategies to reduce negative emotions accordingly (Lazarus 1991). In this study, consumer coping strategies were categorized into engagement (problem-focused, emotion-focused) and disengagement categories. Coping strategies in the engagement category involves individuals actively trying to manage, control, or change both problem- and emotion-focused aspects of the stressful person and/or environment transaction (Tobin et al., 1989). Problem-focused coping occurs when an individual tries to manage the source of the stress. Emotion-focused coping refers to where the individual changes the meaning of the event or regulates the expressing emotions (Lazarus & Folkman, 1984). In the disengagement category, mental disengagement strategy involves doing other things to take one’s mind off the problem, denial (refusing to believe that something has happened), distancing (refusing to think about the problem), and escape/avoidance (wishing problem would go away or somehow be over with). On the other hand, behavioral disengagement strategy involves consumers deciding to give up further action as nothing can be done about the situation. They acknowledge that a goal cannot be reached and that further efforts are futile. As the mechanism behind each type of coping strategy differs, the negative emotions generated from varying conditions are linked accordingly. Since anger arises from appraisals of other-responsibility, angry consumers often manifest in confrontive coping, aggressive action towards the blameworthy organization (Smith & Bolton, 2002). With respect to frustration, one is more likely to foster support-seeking coping as this does not imply blame attribution to a particular person or organization (Roseman, 1991), Further, previous work has suggested that person-related disappointment tends to result in confrontive coping behaviors such as direct complaining (Zeelenberg & Pieters, 2004) and behavioral disengagement (Yi & Baumgartner, 2004). On ther other hand, complaining about it or telling others is unlikely take place for regret as this may highlight he or she mistake (Zeelenberg & Pieters, 2004). Lastly, anxiety tends to be associated with escape behaviors (Roseman, Antoniou, & Jose, 1996). Thus, anxiety consumers often are linked with emotion-focused coping such as mental disengagement. In addition, more proactive, problem-focused coping is likely to take place as stated in some other studies (Yi & Baumgatner, 2004). Proposition 2. Negative emotions have differential impacts on consumer coping strategies. Service failure literature indicates that negative emotions influence diverse retaliatory responses. Romani Grappi and Dalli (2012) contended that negative emotions of anger, discontent, dislike, embarrassment, sadness, and worry are associated with behaviors such as switching, complaining, and negative word of mouth. Maute & Dubé(1999) also indicated that customer anger is liked to exit and negative WOM. Likewise, Blodgett et al. (1999) similarly suggested that consumers are prone to spread negative word of mouth when they perceive service failure. However, even if a particular coping strategy is activated, depending on the strategy applied, the subsequent behavior can be changed. Many researchers indicated that when a service failure is not recovered, it is more likely to lead to negative WOM and complaining behavior (Anderson, 1998). Especially, WOM behavior is more emotion-driven responses (Sundaram, Mitra, and Webster, 1998). Therefore, vindictive WOM behavior is more likely to occur when the emotions are not handled properly. In addition, Kau and Loh (2006) stated that dissatisfied customers who do not directly complain to the firm about their negative experiences may not only engage in vindictive word of mouth behavior, but also switch to another brand. Sabharwal, Soch and Kaur (2010) also suggested that dissatisfied non complaints are likely to exit the service provider more easily resulting in brand switching. Bonifield and Cole (2007) identified conciliatory behaviors to include positive WOM, willingness to return to a service provider, and feeling sympathy for the service provider. Blodgett et al. (1993) suggested that when service failure is recovered, positive word of mouth will take place. Voight (2007) revealed that when certain platform is provided for customers to express their feeling regarding their purchase, customer loyalty increases. Proposition 3. Coping strategies lead to either retaliatory responses or conciliatory responses. Proposition 3-1. Disengaging coping strategies are associated with vindictive WOM, brand switching, complaining behavior more than engaging coping strategies. Proposition 3-2. Engaging coping strategies are associated with positive WOM, re-patronage intention, re-purchase intention. Additionally, our model proposes two individual characteristics as moderators: self-efficacy and self-band connection. Especially, those with high self-brand connection are assumed to counter-argue negative brand information in a service failure situation as this concept captures a strong “self”relevant emotive tie between the brand and the consumer (Escalas, 2004). We contend that these consumers would use prior brand knowledge to neglect their negative emotions and make more brand favoring attributions following service failure. Therefore, depending on the the previous connection with the brand performing the service failure, corresponding coping strategy may change. As self-efficacy relates to the belief that an adequate coping response is available, both factors should relate to the strategies consumers use to cope (Sujan et al., 1999). Proposition 4. Individual characteristics such as self-efficacy and self-brand connection moderates the relationships between negative emotions and coping strategies. Conclusions This paper integrates a broad range of literature into a conceptual framework that delineates consumer coping strategies in a service failure and recovery context. In so doing, the model establishes clear categories for classifying negative emotions consumers experience in a service failure situation into testable elements, and it is argued that although the concept of coping is not a simple one, it should be central to any examination of the service failure and recovery phenomenon. Also, the proposed model considers where marketers’recovery efforts should be directed by describing the ways in which consumers cope with a service failure. How a firm responds to its customers when a service failure occurs can say more about that firm than any other customer interaction. If handled well, it can cultivate emotionally intense relational outcomes. However, if the firm handles the situation badly, it may cause highly negative reactions with customers taking their feedback to online reviews and social media conversations in a way that can seriously damage the firm’s reputation. Future research is needed to empirically test and extend the proposed model. Further empirical research in a particular service setting would advance marketing research as well as be of great managerial significance.

This paper presents how Digital Knowledge Ecosystem such as “Govi Nena” (translates as agriculture intelligence) can be used to provide a more effective and practical solution to eliminate the inefficiencies in agricultural markets and achieve higher productivity and price stability. In order to establish the framework to analyze the system, this paper uses a set of hypothetical scenarios faced by value chain actors based on a review of the literature, established knowledge and recent developing country experiences. The scenario analysis reveals that “Govi Nena” enables farmers to make effective production decisions, deepens the level of value chain integration, and enhances the level of welfare for the society as a whole.

The suspension system of special tracked vehicle is using hydraulic piston pump to adjust track tension and control vehicle position change. During operation of vehicle on rough field, failure of suspension control was occurred due to the piston pump failure. In this study, investigation was performed to analyze the cause of hydraulic piston pump failure. Main reason of piston pump failure is strong peak pressure and insufficient structural safety of shoe. The static stress analysis considering peak pressure was performed to find the weak point of the shoe. From the result, it is confirmed that pass hole of lubrication is the weakest point. Improved piston shoe shows 27% decrease in maximum stress and satisfies the design target which is less than 40% of stress margin.

Use of ICT in Government has ability to improve service delivery to its citizens, and yet many developing countries have lagged behind in the implementation of e-Government. Many e-Government initiatives also failed to achieve their objectives in developing countries. This paper therefore aims to identify critical failure or success factors in Kenya, using Heeks’ Factor Model. A survey questionnaire was developed and data were collected and analyzed from officials and interested citizens. The analysis results enabled to highlight seven specific success and failure factors, and their constituent elements in Kenya. The Kenyan overall e-Government implementation score belongs to the Zone of Improvement (3.52 of total 5.0), which means partial success or failure. The enablers of e-Government projects are good strategy formulation, and internal and external drive, whereas main failures of e-Government are weak ICT infrastructure. The areas for improvement are project management, design, competencies and funding. Data analysis highlights both strengths and weaknesses for each factor or variable. In particular, Kenyan government excels at the drive for change by top to bottom government officers as well as external stakeholders, while the government officers who are using e-Government are satisfied with the availability of vision, strategy and plan of e-Government implementation. Both technologies and e-transactions laws were the worst of all the variables in e-Government implementation. Two areas should be improved using immediate corrective action. In-depth study reveals that government officers and citizens can’t fully use their laptop and mobile devices due to the lack of both ICT network and its operating technology, and legal system associated with the transaction of business information. Finally, the study ends up with recommendations for policy makers to shape the future of e-Government system in both developing and developed countries.

급성 기종성 췌장염은 그 발생 빈도는 매우 드물지만 생명 을 위협할 수 있는 급성 췌장염의 심각한 형태이다. 기종성 췌장염은 장내 가스 형성 세균이 췌장에 침윤하여 발생하는 것으로 알려져 있으며, 복부 전산화단층촬영에서 췌장 실질 내 혹은 후복막강내 기종이 형성되어 있는 특징적인 영상 소견을 보인다. 기본적인 치료는 적절한 수액 공급과 적절한 항생제의 투약으로 감염을 조절하며, 임상 상황에 따라 수술적 제거 또는 경피 배액술을 고려할 수 있다. 본 증례는 73세 남성 환자에서 발생한 급성 기종성 췌장염이 적극적인 수액 및 항생제 치료에도 불구하여 전격성 다발성 장기부전으로 진행하여 사망한 1예로 문헌고찰과 함께 보고한다.

In this paper, we present a new way to derive the mean cycle time of the G/G/m failure prone queue when the loading of the system approaches to zero. The loading is the relative ratio of the arrival rate to the service rate multiplied by the number of servers. The system with low loading means the busy fraction of the system is low. The queueing system with low loading can be found in the semiconductor manufacturing process. Cluster tools in semiconductor manufacturing need a setup whenever the types of two successive lots are different. To setup a cluster tool, all wafers of preceding lot should be removed. Then, the waiting time of the next lot is zero excluding the setup time. This kind of situation can be regarded as the system with low loading. By employing absorbing Markov chain model and renewal theory, we propose a new way to derive the exact mean cycle time. In addition, using the proposed method, we present the cycle times of other types of queueing systems. For a queueing model with phase type service time distribution, we can obtain a two dimensional Markov chain model, which leads us to calculate the exact cycle time. The results also can be applied to a queueing model with batch arrivals. Our results can be employed to test the accuracy of existing or newly developed approximation methods. Furthermore, we provide intuitive interpretations to the results regarding the expected waiting time. The intuitive interpretations can be used to understand logically the characteristics of systems with low loading.

The mobility of the tactical vehicle is important for a mission completion and survivability. During the field operation of the MLRS(Multiple Launcher Rocket System), broken bolt was found in a final reduction gear with oil leakage. It was confirmed that the final reduction gear pad bolt was broken with ductile fracture after inspecting and scanning electronic microscope of the bolt. Furthermore, a finite element analysis on the bolt was conducted with regards to the operating conditions in the final reduction gear. Conducting the analysis, there was a possibility of the bolt being damaged when we put rusty spline and the adhesion of hub thrust pad as input parameters. Finally, improvements on the spline in the shaft are expected in the future by utilizing the result of this study.

Diesel engines show better thermal efficiency and fuel consumption, but diesel engines typically generate more NOx emissions because of lean-burn conditions. Therefore, it is necessary to reduce the emissions of diesel engines either by efficiently controlling combustion or by employing exhaust gas after-treatment systems. In this study several problems we're observed in a SCR system and Engine control system. The analysis result, new technology SCR is suitable for the vehicle with low temperature operating condition. Through this analysis we can find out more effective repair factors from the various fault in SCR component.

보증데이터의 분석 목적은 크게 세 가지로 분류할 수 있다. 첫째 현상파악이다. 현 상파악은 각 부품별 보증클레임데이터를 이용하여 각부품의 현수준을 분석하는 방법 으로 단변량 분석방법이다. 즉 부품의 현 수명(신뢰도)를 분석할 수 있는 생명표법, 카 랜마이어 방법이 대표적이라고 할 수 있다. 둘째, 고장원인분석이다. 부품의 고장에 다 양한 인자가 영향을 줄 것이다. 생산부터 고객의 사용조건까지 다양할 것이다. 이처럼 단순히 사용시간을 가지고 분석하는 것이 아닌 다양한 원인변수를 통해서 원인을 파 악하는 다변량 방법이다. 셋째, 단변량이 아닌 다변량 수명예측방법으로 그 모형의 구 조에 따라 비례적 위험함수 모형 (proportional hazards)의 가정을 적용하는 COX 모형 과 가속화 시간 (accelerated failure time)을 적용하는 AFT 모형으로 분류할 수 있다. 본 연구에서는 예측에 적합한 AFT모형을 통해서 생존 시간 자체에 대한 설명변수 의 효과를 모형화하고 각 부품의 수명을 예측하고자 한다. 이 방법을 제시하는 이유는 COX모형의 경우 준 모수적 방법으로 위험함수의 모수적 유형을 지정하지 않아도 된 다는 장점을 가지고 있지만, 위험 함수 보다는 설명변수의 효과를 추정에 그 주 목적 이 있기 때문에 모형의 결과를 수명예측에 사용하기에는 부적합하다. 본 논문에서는 다양한 인자를 고려하여 부품의 수명 및 수명에 대한 설명변수의 효 과를 모형화 하여 보증데이터를 분석하는 AFT 모형을 제시 하였고 실제 보증데이터 를 통해서 AFT 모형의 활용성을 확인하였다.

The demand from customers on better products and systems seems to be ever increasing. To meet the demand, the systems are becoming more and more complicated in terms of both scale and functionality, thereby requiring enormous effort in the development. One bright spot of this trend is that such effort has been the driving forces of the remarkable advancement in modern systems development. On the other hand, safety issues appear to be critical in many large-scale systems such as transportation and weapon systems including high-speed trains, airplanes, ships, missiles/rockets launchers, and so on. Such systems turn out to be prone to a variety of faults and thus the resultant failure can cause disastrous accidents. For the reason, they can be referred to as safety-critical systems. The systems failure can be attributed to either random or systemic factors (or sometimes both). The objective of this paper is on how to reduce potential systemic failure in safety critical systems. To do so, a proper system design is pursued to minimize the risk of systemic failure. A focus is placed on the fact that complex systems have a lot of complicated interfaces among the system elements. To effectively handle the sources of hazards at the complicated interfaces and resultant failure, a method is developed by utilizing a design structure matrix. As a case study, the developed method is applied in the design of train control systems.

본 연구에서는 고체로켓의 임무 수행 중 연소실 내압으로 인해 발생하는 고체로켓 케이스의 3가지 고장(응력파괴, 균열파괴, 볼트 체결 부 파손) 확률을 효과적으로 예측하는 기법을 개발하였다. 전체적인 확률계산 과정은 다음과 같다: 1) 고체로켓 모터의 고장모드에 영향을 주는 설계 변수선정 및 확률분포 부여, 2) 연소해석을 통한 로켓의 최대작동압력(maximum expected operating pressure, MEOP)의 확률분포 계산, 3) 케이스의 응력과 변형 형상을 구하기 위한 유한요소해석, 4) 3가지 고장함수에 대한 신뢰도예측의 수행. 계산의 편의를 위해 유한요소모델은 축대칭으로 가정하였고 볼트 체결 부의 접촉을 고려하였다. 효율적인 신뢰도예측을 위해 FORM(first-order reliability method) 기법을 통해 MPP(most probable failure point)를 탐색한 후, LHS(latin hypercube sampling)와 반응표면기법을 적용하여 고장모드를 다항식으로 근사화하며, 중요도 추출법을 적용하여 고장확률을 계산하였다.

The O&M (Operation and Maintenance) phase of offshore plants with a long life cycle requires heavy charges and more efforts than the construction phase, and the occurrence of an accident of an offshore plant causes catastrophic damage. So previous studies have focused on the development of advanced maintenance system to avoid unexpected failures. Nowadays due to the emerging ICTs (Information Communication Technologies) and sensor technologies, it is possible to gather the status data of equipment and send health monitoring data to administrator of an offshore plant in a real time way, which leads to having much concern on the condition based maintenance policy. In this study, we have reviewed previous studies associated with CBM (Condition-Based Maintenance) of offshore plants, and introduced an algorithm predicting the next failure time of the compressor which is one of essential mechanical devices in LNG FPSO (Liquefied Natural Gas Floating Production Storage and Offloading vessel). To develop the algorithm, continuous time Markov model is applied based on gathered vibration data.

Failure modes and effects analysis (FMEA) is a widely used engineering tool in the fields of the design of a product or a process to improve its quality or performance by prioritizing potential failure modes in terms of three risk factors―severity, occurrence, and detection. In a classical FMEA, the risk priority number is obtained by multiplying the three values in 10 score scales which are evaluated for the three risk factors. However, the drawbacks of the classical FMEA have been mentioned by many previous researchers. As a way to overcome these difficulties, this paper suggests the ELECTRE III that is a representative technique among outranking models. Furthermore, fuzzy linguistic variables are included to deal with ambiguous and imperfect evaluation process. In addition, when the importances for the three risk factors are obtained, the entropy method is applied. The numerical example which was previously studied by Kutlu and Ekmek‡ioğlu(2012), who suggested the fuzzy TOPSIS method along with fuzzy AHP, is also adopted so as to be compared with the results of their research. Finally, after comparing the results of this study with that of Kutlu and Ekmek‡ioğlu(2012), further possible researches are mentioned.

A progressive failure analysis procedure for composite laminates is completed in here. An anisotropic plastic constitutive model for fiber-reinforced composite material is implemented into computer program for a predictive analysis procedure of composite laminates. Also, in order to describe material behavior beyond the initial yield, the anisotropic work-hardening model and subsequent yield surface are implemented into a computer code, which is Predictive Analysis for Composite Structures (PACS). The accuracy and efficiency of the anisotropic plastic constitutive model and the computer program PACS are verified by solving a number of various fiber-reinforced composite laminates with and without geometric discontinuity. The comparisons of the numerical results to the experimental and other numerical results available in the literature indicate the validity and efficiency of the developed model.

Modern systems development becomes more and more complicated due to the need on the ever-increasing capability of the systems. In addition to the complexity issue, safety concern is also increasing since the malfunctions of the systems under development may result in the accidents in both the test and evaluation phase and the operation phase. Those accidents can cause disastrous damages if explosiveness gets involved therein such as in weapon systems development. The subject of this paper is on how to incorporate safety requirements in the design of safety-critical systems. As an approach, a useful system structure using the method of design structure matrix (DSM) is studied while reflecting the need on systems safety. Specifically, the effects of system components failure are analyzed and numerically modeled first. Also, the system components are identified and their interfaces are represented using a component DSM. Combining the results of the failure analysis and the component DSM leads to a modified DSM. By rearranging the resultant DSM, a modular structure is derived with safety requirements incorporated. As a case study, application of the approach is also discussed in the development of a military UAV plane.

A progressive failure analysis procedure for composite laminates is developed in here and in the companion paper. An anisotropic plastic constitutive model for fiber-reinforced composite material, is developed, which is simple and efficient to be implemented into computer program for a predictive analysis procedure of composites. In current development of the constitutive model, an incremental elastic-plastic constitutive model is adopted to represent progressively the nonlinear material behavior of composite materials until a material failure is predicted. An anisotropic initial yield criterion is established that includes the effects of different yield strengths in each material direction, and between tension and compression. Anisotropic work-hardening model and subsequent yield surface are developed to describe material behavior beyond the initial yield under the general loading condition. The current model is implemented into a computer code, which is Predictive Analysis for Composite Structures (PACS), and is presented in the companion paper. The accuracy and efficiency of the anisotropic plastic constitutive model are verified by solving a number of various fiber-reinforced composite laminates with and without geometric discontinuity. The comparisons of the numerical results to the experimental and other numerical results available in the literature indicate the validity and efficiency of the developed model.