• Management Science and Financial Engineering
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• v.5 no.1
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• pp.1-25
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• 1999

There is a worldwide trend to automate the handling operations in port container terminals in an effort to improve productivity and reduce labor cost. This study iscusses how to apply an AGV(automated guided vehicle) system to the handling of containers in the yard of a port container ter-minal. The main issue of this paper is how to assign tasks of container delivery to AGVs during ship operations in an automated port container terminal. A dual-cycle operation is assumed in which the loading and the discharging operation can be performed alternately. Mixed integer linear program-ming formulations are suggested for the dispatching problem. The completion time of all the dis-charging and loading operations by a quayside crane is minimized, and the minimization of the total travel time of AGVs is also considered as a secondary objective. A heuristic method using useful properties of the dispatching problem is suggested to reduce the computational time. The perfor-mance of the heuristic algorithm is evaluated in light of solution quality and computation time.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.5
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• pp.1267-1285
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• 2012

Wireless Body Area Networks (WBANs) deal with variety of healthcare services with diverse Quality of Service (QoS) requirements. However, QoS handling is a challenging problem in such networks. In general, QoS related problems can be addressed from different layers in the networking protocol suite. Design of an efficient QoS aware Medium Access Control (MAC) protocol can address this problem in MAC layer. This paper analyzes the QoS requirements of WBAN, identifies the requisites of QoS handling system, and outlines the trends that are being followed for its advancement with focus on QoS issues at MAC layer. We review some prior works, compare them, and analyze the current research concerned with problem of providing QoS in WBAN. We also explore some open issues and discuss them.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.21 no.4
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• pp.34-40
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• 2013

Attitude command response type required for enhanced handling qualities of helicopter can be implemented by mechanical automatic flight control system with SAS actuators which have limited authorities. However, the early saturation of SAS actuator hinders the helicopter from following the attitude command for large stick command. Auto-trim controller can delay SAS actuator's saturation by utilizing trim actuators and allows the attitude command response type for larger stick command. This paper describes the control law for limited authority system of helicopter with auto-trim. Limited authority system is applied to BO-105 linear dynamic model and simulation is performed along with handling quality analysis.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.2
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• pp.103-110
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• 2022

Degradation of handling qualities(HQs) due to bad weather or mechanical failure can pose a fatal risk to pilots unfamiliar with such situation. In particular, icing is an important issue to consider as it is a frequent cause of accidents. Most of the previous research works focuses on aerodynamic performance changes due to icing and the corresponding icing modeling or methods to prevent icing, whereas the present work attempts to actively compensate for HQ degradation due to icing on a full-scale helicopter through flight control law design. To this end, the present work first demonstrates HQ degradation due to icing using CONDUIT software, and subsequently presents a robust control design via the RS-LQR(Robust Servomechanism Linear Quadratic Regulation) procedure to compensate for the HQ degradation. Simulation results show that the proposed robust control maintains Level 1 HQ in the presence of icing.

• Journal of Korean Society for Quality Management
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• v.40 no.4
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• pp.543-558
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• 2012

Purpose: The purpose of this study was to propose useful suggestions by analyzing causal effect relationship between port service quality, and customer satisfaction and performance in port industry. Methods: The collected data through the survey were analyzed using multi-regression analysis. The measurement tools used for this study were divided into three dimensions such as internal quality, interaction quality and environmental quality. Results: The results of this study are as follows; regarding the influence of pot service quality dimension on customer satisfaction, it was found that the effects of interaction quality and internal quality were significant and those of environmental quality was not significant on customer satisfaction. It was found that customer satisfaction made statistically significant influence on performance from the investigation of the causal effect relationship between customer satisfaction and performance. Conclusion: Incheon Port needs to act actively paying attention to port facilities, efficient operation, network, cargo recruitment activities, smooth communication and fast handling.

• Journal of Korean Society for Quality Management
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• v.32 no.3
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• pp.216-233
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• 2004

The real estate management includes not only the brokerage, property management, development, investment and consulting which are related to real estate handling, but also the human resources who deal with the real estate business. The level of management quality of Korean real estate business is rather poor. This paper deals with management innovation of real estate management using Six Sigma methodology The main focus of this Paper is to develop strategy Planning, and is to select critical success factors for each strategy to make an advanced management system for real estate business. This paper is a case study, and the target company for this innovation is ERA-Korea Company. Seven strategies are proposed, and for each strategy several critical success factors are suggested. Through this case study, the authors hope that a management quality model for real estate business is proposed, and an improved management method can be adopted in the other real estate companies.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2004.11a
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• pp.53-68
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• 2004

Eggshell quality is one of the most important factors that influence hatchability. The porosity and overall quality of eggshell have a very significant effect on exchange of vital gas (carbon dioxide and oxygen) between the developing embryo and the air during incubation. Thin-shelled eggs showed the greater weight loss than do thick-shelled eggs. causing the chick to have difficulty in hatching. Thin-shelled eggs also have a much greater chance of being cracked during handling. On the other hand. thick-shelled eggs showed the higher hatchability as a result of greater fertility and lower intermediate and late embryonic mortalities. Even a small percentage improvement in the eggshell quality could result in significant saving to the breeder industry in an increasingly competitive environment. Many factors including nutrition. management practices, environmental conditions and breeding are known to be related to eggshell quality. In this review brief accounts of each factor associated with eggshell quality and hatchability were provided. We conducted three experiments to investigate the effects of dietary Ca. vitamin D3 metabolite and some bioactive materials on eggshell quality and hatching egg production. The results of our studies showed that relatively high levels of dietary Ca in combination with 25-hydroxycholecalciferol had beneficial effects on improving eggshell quality and reproductive performances in aged egg-type breeder hens. It was also suggested that the proper use of some feed additives such as isoflavon and chitosan might provide means of improving eggshell quality and reproductive performances in aged egg-type breeder hens.

• The Journal of Information Systems
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• v.16 no.4
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• pp.107-129
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• 2007

The purpose of this study is to examine the effect of logistics service quality and relationship orientation factors on customer satisfaction and loyalty in the electronic commerce context. Based on extensive review of relevant literature, nine components of logistics service quality(i.e. information quality, ordering procedures, ordering release quantities, timeliness, order accuracy, order quality, order condition, order discrepancy handling and personnel contact quality) and six components of relationship orientation(i.e. trust, bonding, communication, shared value, empathy and reciprocity) are introduced in this study. And a conceptual model is developed and five research hypotheses are empirically examined using structural equation modeling. The findings indicate that logistics service quality and relationship orientation are positively and significantly associated with customer satisfaction, and customer satisfaction is the antecedent variable of customer loyalty in the Internet Shopping Mall. In addition, a significant impact of logistics service quality on relationship orientation of the customer is revealed. Implications of these findings are discussed, and limitations of the study as well as further research directions are addressed.

• Korean Journal of Community Nutrition
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• v.15 no.3
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• pp.379-392
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• 2010

The purposes of this study were to investigate recipients' handling and consumption of home-delivered meals at home and to assess their perceptions on home-delivered meal services for older adults. A total of 312 elderly people who received home-delivered foodservice were surveyed using an individual interview technique. A statistical data analysis was completed using SPSS (ver. 14.0). It was found that 90.2% (n = 166) of the lunch box recipients received services for six days per week, and 76.6% (n = 95) of the side-dish recipients got services once per week. More than half of the clients reported that they cooked meals by themselves on days when meals were not delivered. The two hundred thirty-two (75.3%) ate their meals as soon as they were delivered. It was found that 66.8% of the lunch box recipients and 7.3% of the side-dish recipients left delivered meals on the counter (at room temperatures) before eating. Only 11.4% of the lunch box recipients and 48.4% of the side-dish recipients kept delivered meals in the refrigerator before eating. Less than half of the lunch box recipients consumed all foods they were served at once. The reasons the recipients did not eat their all meals delivered at once were "saving for next meals" and "big portion size" Of those clients who left delivered meals, 19% of the lunch box recipients and 9.7% of the side-dish recipients ate leftovers without reheating. An average score of quality of delivered meal services was 3.5 out of 5 points. The results suggest that the clients of the home-delivered meal service should be provided information on proper handling and consumption practices with delivered meals at home. The findings of the study will be used to develop nutrition and food safety management guidelines for senior foodservice.

• Journal of the Korean Society of Clothing and Textiles
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• v.35 no.5
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• pp.561-574
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• 2011

This study investigates the ultimate factor structure of consumer dissatisfaction with the off-line purchase and usage of clothing. It identifies the determinant dimensions of consumer dissatisfaction on clothing purchase and usage and investigates the hierarchical structure of consumer dissatisfaction by assessing and comparing the effectiveness of five alternative factor structure models. A total of 300 women were online-surveyed to assess the level of dissatisfaction based on their dissatisfying experience with clothing purchases and usage in terms of product quality, price, salesperson's attitude, and store environment. The exploratory factor analysis identified the underlying dimensions of dissatisfaction: Handling, Aesthetics, Salesperson, Size, Price, Product Quality, Service, and Environment. By employing a first-order confirmatory factor analysis and higher-order confirmatory factor analysis, consumer dissatisfaction was confirmed to have a hierarchical structure with three second-order constructs Intrinsic instrument is manifested by handling, quality, and size, Intrinsic expression consists of service, salesperson, and environment, and Extrinsic circumstance contains aesthetics and price. On empirically demonstrating the multi-dimensional constructs of consumer dissatisfaction by identifying its hierarchical structure, the study provides the theoretical and practical insights to comprehend consumer purchase and post-purchase behavior. Specifically, it affords an empirical platform to extend the scope of research with condensed concepts of dissatisfaction to researchers. In addition, it also enables marketers to take a broader view of consumer dissatisfaction by providing cues about potential problems and identifying the source of those problems.