• Proceedings of the KIEE Conference
• /
• 1999.11b
• /
• pp.331-333
• /
• 1999

Power supply for Nuclear Power Plant was developed, and MMI monitoring circuit was added to the main function of power supply. The developed power supply is designed to show equal or higher performance compared with the existing power supplies. Performance of the power supply is verified by simulations, experiments, and authentication test for Q-class, he status of power supply and fault waveform can be displayed and analyzed on PC by RS-232C port. By adopting the latest parts, mainly domestic models, production cost and delivery can be reduced. Replacement period of capacitor can be extended by life estimation.

• 제어로봇시스템학회:학술대회논문집
• /
• 2000.10a
• /
• pp.406-406
• /
• 2000

In this study, as a part developing an unmanned container terminal (UCT), Ive designed and implemented an Autonomous Ground Vehicle (AGV) that can deliver containers in the port fast and safely as they are scheduled. It is preferable to research the intelligent UCT/AGV for delivering containers all day long without causing any trouble. For the sake of safe and fast AGV driving, we implemented a multiple-sensor system with vision, ultrasonic, and IR sensors and we adapted the hight-speed wireless LAN that satisfies the IEEE 802.11 Standard for hi-directional communication between the main processor in AGV and a host computer. The Pentium-III processor board mounted on the bottom frame in AGV combines and computes the information from sensors and controls the AGV driving. There are also the 80C196KC micro-controllers to control the actuating and steering motors. In addition, a steering function that is defined newly in this paper is heavily concerned in the mechanical design, and it plays an important role when AGV moves along a curve. Experimental results show the fast and safe delivery operations are possible with this UCT/AGV

• IE interfaces
• /
• v.23 no.1
• /
• pp.12-23
• /
• 2010

A semiconductor market is one of the most competitive markets in the world. To survive this competition, important targets for production planning are on-time delivery and profit maximization. In our research, we modify the linear programming model for the current production planning by adding new objective functions that maximize the profit. In addition, we propose a production planning process that gives a priority to new products, reflecting daily fluctuations in demand to weekly production planning. We validate our model with real data sets obtained from a major company semiconductor manufacturer and performed the paired t-test to verify the results. The results showed that our model forecasted profit and loss with 93.2% accuracy and improved the due date satisfaction by 10%.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2006.06a
• /
• pp.533-534
• /
• 2006

In this paper we propose a new model of a mini-pump with peristaltic motion and present the results of the finite element analysis of an electromagnetic micro actuator. The mini-pump consists of three diaphrams made of PDMS, three permanent magnets in cylinders, printed copper coils on glass substrates, and input and output port. The size of the mini-pump is $14\;{\times}\;40\;{\times}\;5.4$ mm3 and the permanent magnet diameter 6.2 mm $\times$ thickness 2 mm. The electromagnetic force applied on the magnet was about 0.84 N when the current of coils was 1 A, then the maximum displacement of the PDMS diaphram was about 2mm.

• Journal of Korea Port Economic Association
• /
• v.39 no.3
• /
• pp.191-210
• /
• 2023

The Covid-19 pandemic has had a significant impact on global logistics and supply chains, leading to major discrepancies in logistics performance across countries worldwide. Through an examination of logistics performance index and supply chain tracking data, this study aimed to identify the changes in global supply chains and logistics environments during the pandemic. The analysis of the logistics performance index showed that overall, countries around the world, especially developed nations, showed improvements in metrics such as customs and border management efficiency, the quality of trade and transport infrastructure, capability and quality of logistics services, and cargo tracking abilities. However, the competitive pricing feasibility of international transportation and the on-time delivery frequency of goods saw a decline due to the pandemic's effects. The supply chain tracking data revealed that ports in Asian countries demonstrated high processing efficiency. In contrast, the U.S. and European countries took comparatively more time. Particularly for air cargo, parcels, and express shipments, the U.S. showed relatively longer processing times, leading to logistical delays. In conclusion, during the Covid-19 pandemic, Asian countries maintained relatively high efficiency in their logistics and trade environments. Conversely, the U.S. and some European countries showed delays and decreased efficiency in various metrics. In the future, efforts should be made to address delays and congestion, namely, the deceleration of logistics processes.

• Journal of Internet Computing and Services
• /
• v.6 no.6
• /
• pp.127-137
• /
• 2005

This paper presents implementation of client-based VOD service using multicast delivery, Conventional system provide server-based system in multicast delivery but implemented system provides on-demand client-based multicast system. The Multicast Agent Scheduler aggregates clients' request and it generate multicast group addresses and port numbers according to requested video items and service request time. Then it transmits immediately multicast address to VOD server and client who request service. And then VOD server transmits requested streams with a multicast group address and the client joins the group automatically. The Multicast Agent Scheduler assigns the same multicast group address when other clients request an identical video within the same scheduling duration. The proposed system can reduce load of server and support many clients at the same time and applies it to WMT(window media technology) of Microsoft.

• Journal of Korea Port Economic Association
• /
• v.31 no.4
• /
• pp.151-168
• /
• 2015

Shippers face uncertainty and risks until the delivery of goods to the buyer (importer). To avoid these uncertainty and risks, shippers use the abroad logistics center and then try to construct continuous contract relations. From this viewpoint, this study examines the motivations of shippers to take advantage of the logistics center and perception difference for service quality according to the characteristics of shippers. For this purpose, T-test and ANOVA analyses are conducted using SPSS 21.0. The results suggest the following implications. First, there are no differences in perception regarding the motivation to take advantage of the logistics center for the size and characteristics of products. Second, the main motivating factors are maneuver to competitors and meeting buyers' demands by using the abroad logistics center. Furthermore, there is the level of perception for service quality regarding packaging and labeling in the logistics center. In contrast, the problem process and the quality of the order progress information is higher. Finally, specific logistics services are required depending on individual products because each product's characteristics are different.

• Journal of Navigation and Port Research
• /
• v.40 no.6
• /
• pp.469-476
• /
• 2016

This study investigates cargo management issues in the shipbuilding and marine equipment industry. Problems are analyzed concerning the absence of information about exact cargo location and condition, damage, loss, replacement, and transportation delays during the import and export process. Then, improvements are proposed to solve these problems. To illustrate, real time information about the status and location of cargo should be communicated between import/export and logistics companies to facilitate material logistics for shipbuilding & marine equipment. In addition, a standard cargo classification and recognition system should be established to reduce delivery delays and mistakes, so then enhancing logistical efficiency. Moreover, it is also necessary to nurture professional shipbuilding & marine equipment forwarders to strengthen their expertise with professional education and training.

• Journal of Korea Port Economic Association
• /
• v.28 no.4
• /
• pp.39-57
• /
• 2012

This study aims to find out the relationship of customer behavioral intention and marketing variables such as service quality and customer satisfaction which are regarded as its determinants. And then this study has suggested what service factors shall be emphasized to induce the latent customers. And it has grouped strategic Schemes on which service variables shall be focused to enhance the existing customer behavioral intentions. This study has found, to the existing customers, only physical environments among 3 dimension components of Service quality significantly affects to the Behavioral intentions. Priorly, marketing efforts, namely, expansion of convenient facilities such as special berth construction is necessary. To the latent customer, service delivery is the most powerful factor to the behavioral intentions. Consequently, frequency of cruise calling, Facilities of shopping and eating, issues and their development of cruise goods and publicity and promotions are needed.

• Journal of Korea Port Economic Association
• /
• v.28 no.2
• /
• pp.195-211
• /
• 2012

As the globalisation of corporate's managemental environment, all parts of logistics such as procurement, production and sales are globalized. The ways of transportation in Korea and Japan, where are difficult to use land-transportation, are sea-transportation and air-transportation. Sea & air is a way of the international transportation which is combined by Sea and Air to reduce the transportation fee and shorten the delivery time. The main body of multimodal transportation service is the corporate, actual carrier who undertakes the actual transport. It is essential to establish service quality to maintain their going concern. In other words, the actual carrier has to emphasize the importance of service quality to forwarder tan any other business conditions. In this study, we examine the determinants of service quality for actual carrier in multimodal transportation. Through the multi-regression analysis based on SERVPERF by Cronin and Taylor (1992), we analyze the service quality dimensions of actual carrier. Also we examine the relations between the determinants and customer's satisfaction. Using statistical hypothesis testing, the determinants of service quality are reliability, responsiveness, assurance, tangibles, and we could look into the factors which the actual carrier should control with priority.