• Wind and Structures
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• v.23 no.6
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• pp.559-575
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• 2016

In order to investigate the influence of different blade positions on aerodynamic load and wind loads and load-effects of large scale wind turbine tower under the halt state, we take a certain 3 MW large scale horizontal axis three-blade wind turbine as the example for analysis. First of all, numerical simulation was conducted for wind turbine flow field and aerodynamic characteristics under different halt states (8 calculating conditions in total) based on LES (large eddy simulation) method. The influence of different halt states on the average and fluctuating wind pressure coefficients of turbine tower surface, total lift force and resistance coefficient, circular flow and wake flow characteristics was compared and analysed. Then on this basis, the time-domain analysis of wind loads and load-effects was performed for the wind turbine tower structure under different halt states by making use of the finite element method. The main conclusions of this paper are as follows: The halt positions of wind blade could have a big impact on tower circular flow and aerodynamic distribution, in which Condition 5 is the most unfavourable while Condition 1 is the most beneficial condition. The wind loads and load-effects of disturbed region of tower is obviously affected by different halt positions of wind blades, especially the large fluctuating displacement mean square deviation at both windward and leeward sides, among which the maximum response occurs in $350^{\circ}$ to the tower top under Condition 8; the maximum bending moment of tower bottom occurs in $330^{\circ}$ under Condition 2. The extreme displacement of blade top all exceeds 2.5 m under Condition 5, and the maximum value of windward displacement response for the tip of Blade 3 under Condition 8 could reach 3.35 m. All these results indicate that the influence of halt positions of different blades should be taken into consideration carefully when making wind-resistance design for large scale wind turbine tower.

• Journal of Distribution Science
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• v.13 no.2
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• pp.63-73
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• 2015

Purpose - Satisfaction with service is evaluated according to customers' subjective judgment. The expected value of customer service and its evaluations depend on the customers' position. The customer recognizes two different forms of service levels. One is satisfaction and the other is dissatisfaction. Customers who are satisfied want to receive the service in future. However, those dissatisfied try to change the service. The service provider tries to improve the service. There are two different service cycles. One is the successful cycle and the other is the failure cycle. This study aimed to empirically determine the effects of the justice and authenticity of service recovery on customer behavioral intention through an integrated approach to cognitive justice and psychological authenticity. Research design, data, and methodology - Based on a literature review, justice of service recovery was categorized into three types: distributive, procedural, and interactive. Then, authenticity was added to obtain four independent variables, along with recovery satisfaction as a parameter. Behavioral intention, as an outcome variable, was divided into the repurchase intention and positive word-of-mouth. The model and hypotheses were created and measurement items were developed. A questionnaire survey of items concerning the service recovery experience at family restaurants was conducted on college students and residents in Gwangju from September 30 to October 31, 2013. A total of 400 copies of the questionnaire were sent out and 385 were returned. Respondents answered questions about the importance of, and satisfaction with service recovery on a 5-point Likert scale. Excluding 174 copies without service failure experiences and 7 inappropriate copies, 204 copies were analyzed using SPSS 21.0 for Windows and AMOS 20.0 to determine the reliability and validity of measurements. The hypotheses were tested through a goodness-of-fit analysis. Results - First, distributive justice positively affected recovery satisfaction. Second, procedural and interactive justice had no impact. Third, authenticity positively affected recovery satisfaction. Fourth, distributive justice had relatively stronger effects on recovery satisfaction than authenticity. Fifth, recovery satisfaction significantly affected repurchase intention and positive word-of-mouth and it proved effective in mediation. Finally, additional analysis was performed for descriptive statistics of the principal variables by various demographic characteristics and significant differences were found in gender, occupation, and so on. Conclusions - This study has academic significance as the fairness and authenticity of service recovery were investigated to reveal the effects on behavior. The findings could be applied to a wide range of service recovery strategies. However, there are some limitations. First, data was collected only from the residents of Gwangju and most respondents were aged 20-30. Future studies should target a wide range of areas and age groups. Second, because the questionnaire used in this study targets only convenience family restaurants, the results of this study cannot be generalized to all services companies. Future research should be done on a wide range of industries such as hotels, airlines, and hospitals, and perform a comparison between sectors.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.443-450
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• 2020

This paper reports a design improvement study to solve the stoppage phenomenon caused by the launch-support device applied to K105A1. The K105A1 is a weapon system equipped with an old 105 mm towed howitzer in a wheeled vehicle, which provides superior maneuverability compared to track equipment. The launch support device serves to withstand fire impact and load. In this way, this device is fixed firmly to the ground in preparation for the shooting mission and is responsible for the critical performance, such as fixing the position of the vehicle. On the other hand, during the field test, a temporary stoppage of the launch support occurred, which caused a problem of not being fixed to the ground. To solve this problem, the cause of failure was analyzed by a replay test and parts inspection. In addition, the operating concept, method, and design were analyzed to derive the cause and solve the problem by changing the parts design. Finally, the performance and firing missions were performed normally by applying the changed design to K105A1. The performance stability and reliability of the launch support device were confirmed, which are expected to be of great assistance in the development of military equipment in the future.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.6
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• pp.2575-2587
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• 2011

Whereas the early financial information technology invested a large amount of investment on developing and adopting its own new systems. it is now focusing on reducing expenses and improving internal efficiency but applied for securing a company's competitive advantage considering the long term strategic level. As relevant researches, studies on information system quality and performance are actively going on. In previous research, the relations of the influence on the financial performance by information system quality or absorption capacity have been reviewed. In other words, the information system quality and absorptive capacity, respectively, in the position of the independent variables have been studied as a factor to have a significant effect on financial performance while the research on the relationship between these two variables is lacking. Thus, in this researches, quality of financial information systems and the absorptive capacity, respectively, as independent variables and parameters on the mediating effect on the financial performance were researches. As a result, quality of financial information systems showed a positive effect on the performance of company, the absorption capacity was perfect to play the role of mediating one. However, absorptive capacity as an independent variable has a positive impact on financial performance, but the quality of financial information systems as a parameter was not affected in any manner.

• Journal of Distribution Science
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• v.13 no.11
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• pp.93-100
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• 2015

Purpose - The objective of this research is to investigate whether national culture influences consumers' service evaluations. The services industry is receiving increasing attention from academia and practitioners as its position grows in global markets. Standardization or localization is a traditional managerial decision in global business. As the boundaries of services expand across national borders, firms are required to decide whether to standardize services or adjust to local needs. Though it is imperative to reflect global perspectives in marketing theories, these perspectives are mostly based on Western conceptualization of the world. Through a comparison of consumer groups from two culturally remote countries, service quality evaluation mechanisms are examined based on similar stimuli. The study tries to expand service marketing perspectives across national borders. Research design, data, and methodology - Eastern and Western countries are known to be culturally distinct. One Eastern and one Western country were chosen: an Anglo-Saxon country (the U.S., England, and Australia) and South Korea. In Hofstede's cultural dimensions, the differences between the two are pronounced. The Anglo-Saxon based countries share many similarities. Samples of the same sites are targeted. Questionnaires using a service quality scale (SERVQUAL) and a customer satisfaction scale were distributed. Utilizing Hofstede's typology of culture, the service evaluation mechanisms of the respondents from the two groups are evaluated. Three hypotheses are proposed from the review of the literature. These are service evaluation habits, importance of service quality dimensions for the individualistic/collectivistic countries, and strong/weak uncertainty avoidance cultures. Consumers from the individualistic countries are considered to care about themselves and demand a higher level of responsiveness and assurance. On the other hand, consumers from high uncertainty avoidance cultures are assumed to rely more on tangible questions of service quality, as these are the only predictable service quality indicators. A t-test and regression analysis are applied to validate the constructs. Results - The respondents from the Anglo-Saxon countries are more generous on service evaluations than Koreans. Researchers have indicated that Americans tend to give higher service evolution scores than European, Mexican, and Korean counterparts. The tendency is the same here. The sample from Anglo-Saxon countries demonstrated higher service evaluation scores on every dimension of SERVQUAL. For the second hypothesis, the respondents from the collectivistic culture rely less on core service dimensions (assurance and responsiveness) due to their tendency to place more value on group harmony than individual interest. However, the third hypothesis was not validated. Conclusions - The study attempted to expand the scope of service marketing to reflect cross-national perspectives. Service quality is known to have a strong influence on customer satisfaction and loyalty behavior. However, this research demonstrated that individuals from different cultural territories respond heterogeneously to the same stimuli. Scholars argue that national cultures are main factors in such deviated behavior. Scholars and global managers should be aware of differences in consumer value judgment mechanisms such as satisfaction, expectations, and perceptions.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.5 no.1
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• pp.47-52
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• 2011

The functional loot orthoses, when wearing shoes, are in the direct contact with bottom of foots to improve and recover the correctness of abnormal lower limb musculoskeletal imbalance and the primary role of foot and also, it can act to keep the balance and weight of body and support the weakened region, so that it is very helpful to keep body balance for the standing position. In this paper, it was researched that foot orthoses which is accommodable for the function of impact absorption including the gait stability affect on the balanced performances of body in according to the formation and the material of foot part. Taking into account the balanced performances by using the sway velocity, the estimation and comparison of the effects on the balanced performances by each formation and material for foot orthoses was evaluated into significant values(p<0.006) in only the eye-opening posture with Firm state, In this posture, the static process performed by each foot formation reveals in order of normal foot(p<0.010), flat foot(p<0.000) and hollow foot(p<0.003) and then, on the base of each formation of foot part, the result that analyze the effects of the materials of foot orthoses on the balance performance appeared showing that soft materials is more effective on the normal foot and, on the other hand, rigid materials is more effective in balancing on flat foot and hollow foot.

• Journal of Korean Society on Water Environment
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• v.32 no.3
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• pp.243-252
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• 2016

In cases of water pollution accidents, accurate prediction for arrival time and concentration of contaminants in a river is essential to take proper measures and minimize their impact on downstream water intake facilities. It is critical to fully understand the behavior characteristics of contaminants on river surface, especially in case of oil spill accidents. Therefore, in this study, the effects of main parameters of advection and diffusion of contaminants were analyzed and validated by comparing the results of Lagrangian particle tracking (LPT) simulation of Environmental Fluid Dynamic Code (EFDC) model with those of Global Position System (GPS)-equipped drifter experiment. Prevention scenario modeling was accomplished by taking cases of movable weir operation into account. The simulated water level and flow velocity fluctuations agreed well with observations. There was no significant difference in the speed of surface particle movement between 5 and 10 layer modeling. Therefore, 5 layer modeling could be chosen to reduce computational time. It was found that full three dimensional modeling simulated wind effects on surface particle movements more sensitively than depth-averaged two dimensional modeling. The diffusion range of particles was linearly proportional to horizontal diffusivity by sensitivity analysis. Horizontal diffusivity estimated from the results of GPS-equipped drifter experiment was 0.096 m²/sec, which was considered to be valid for applying the LPT module in this area. Finally, the scenario analysis results showed that particle movements could be stagnant when discharge from the upstream weir was reduced, implying the possibility of securing time for mitigation actions such as oil boom installation and wiping oil contaminants. The outcomes of this study can help improve the prediction accuracy of particle tracking simulation to establish the most suitable mitigation plan considering the combination of movable weir operation.

• The Journal of Korean Society for School & Community Health Education
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• v.9 no.2
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• pp.65-80
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• 2008

Objectives: To identify the relationship between the internet addition of elementary school students, and their health behavior and VDT syndrome, and thereby to detect the impact of internet addiction on the health behavior of elementary school students, to get the basic information necessary to develop a prevention program for internet addiction and to plan for VDT syndrome prevention program. Methods: We conducted this study during the period from jun 27, 2007 through July 8, 2007. The subjects of this study were 416 children whose grades were in 4th through 6th grades of elementary schools located in the city A in Kyung Pook Providence. Data were obtained from self-rating questionnaires. The questionnaires were composed of Korean Internet Addiction Self-examination on Internet Use Patterns (K-scale), Health Behavior Profile, VDT Syndrome, and general characteristics. We used t-test, AVOVA with Ducan method for Post-hoc comparison in means comparison between groups, $X^2$-test for frequency analysis and Pearson's correlation coefficient. We used SPSS/PC(12.0 ver) program and the LISREL 8.53 Win program for covariance structural analysis. Results: Major results were as follows. 1. The internet addiction propensity distribution based on the distribution of scores were investigated according to the self diagnosis scale on internet addiction. 6.5% of them were high risk user group, 14.4% were potential risk users and 79.1% of them were common user groups. 2. Internet addictions by sex, internet use duration, frequency (days/week), time(hours/day), purpose, position, brightness of internet, attitude of parents and frequency of conversation of family members were statistically significant(p<0.01). 3. There was a statistically significant difference in VDT syndrome according to internet addiction groups(p<0.001) besides ocular symptoms, dry mouth and GI troubles. 4. The health behavior score was the lowest in high risk user group(p<0.001). There were significant differences between internet addiction groups in personal hygiene and habits of daily living(p<.002), the prevention of accidents(p<.002), the practice concerned with the prevention of infectious disease(p=.002), and mental health(p<.001). 5. There was also a significant negative correlation between internal addiction and health profile(r=-0.365, p<0.01) and a significant positive correlation between internal addiction and VDT syndrome(r=0.331, p<0.01). 6. As the result of structural model analysis, internet use time(/day), days of internet use(/1week), conversation frequency among family members, degree of brightness of internet use had significant direct effects on internet addiction. Conclusions: The results will help the development of an effective intervention program for the prevention and treatment of internal addiction by clarifying the effect of the internal addiction upon elementary school students' VDT syndrome and health behavior.

• Journal of Electrochemical Science and Technology
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• v.11 no.2
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• pp.172-179
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• 2020

The impact of effective parameters on the electrodeposition rate optimization of Au-Cu alloy at high thicknesses on the silver substrate was investigated in the present study. After ensuring the formation of gold alloy deposits with the desired and standard percentage of gold with the cartage of 18K and other standard karats that should be observed in the manufacturing of the gold and jewelry artifacts, comparing the rate of gold-copper deposition by direct and pulsed current was done. The rate of deposition with pulse current was significantly higher than direct current. In this process, the duty cycle parameter was effectively optimized by the "one factor at a time" method to achieve maximum deposition rate. Particular parameters in this work were direct and pulse current densities, bath temperature, concentration of gold and cyanide ions in electrolyte, pH, agitation and wetting agent additive. Scanning electron microscopy (SEM) and surface chemical analysis system (EDS) were used to study the effect of deposition on the cross-sections of the formed layers. The results revealed that the Au-Cu alloy layer formed with concentrations of 6gr·L^-1 Au, 55gr·L^-1 Cu, 24 gr·L^-1 KCN and 1 ml·L^-1 Lauryl dimethyl amine oxide (LDAO) in the 0.6 mA·cm^-2 average current density and 30% duty cycle, had 0.841 ㎛·min^-1 Which was the highest deposition rate. The use of electrodeposition of pure and alloy gold thick layers as a production method can reduce the use of gold metal in the production of hallow gold artifacts, create sophisticated and unique models, and diversify production by maintaining standard karats, hardness, thickness and mechanical strength. This will not only make the process economical, it will also provide significant added value to the gold artifacts. By pulsating of currents and increasing the duty cycle means reducing the pulse off-time, and if the pulse off-time becomes too short, the electric double layer would not have sufficient growth time, and its thickness decreases. These results show the effect of pulsed current on increasing the electrodeposition rate of Au-Cu alloy confirming the previous studies on the effect of pulsed current on increasing the deposition rate of Au-Cu alloy.

• Journal of Broadcast Engineering
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• v.13 no.6
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• pp.781-795
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• 2008

This paper focuses on effects that IPTV will have on domestic broadcasting market in the point of view of customers. The purpose of the paper is to present the future landscape of competitive media market when IPTV is launched, and to research how IPTV will have impact on terrestrial broadcasting, cable TV and satellite broadcasting industry. The paper integrates two known theories, such as the niche-gratification model and the value-expectancy model, to analyze competitive media market. The value expected model makes it possible to overcome the weakness of the niche-gratification model and to forecast competitiveness more accurately. According to this research, competitive power will be in the order of Cable TV, IPTV, and satellite broadcasting. Terrestrial broadcasting does not show strong competitive relationships with others statistically. As a result, Cable TV will be the most competitive medium in the future. IPTV will be stuck in the middle and can rapidly substitute for existing broadcasting services. While IPTV will severely threaten the satellite broadcasting company which has a relatively small number of subscribers, cable TV will be in a superior position to IPTV.