• Bulletin of the Korean Space Science Society
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• 2008.10a
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• pp.37.1-37.1
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• 2008

Space Science and Technology Laboratory at Kyung Hee University developed an 80cm Nasmyth telescope with the joint work of Space & Astronomy, Inc. It was set up at Muju county public astronomical observatory in Jeonlabuk-Do. Nasmyth focus system was selected for the telescope to use two focal points by a rotatable tertiary mirror. Focal ratios of the telescope are f10, f5 respectively. Support of the main mirror is made with Lasalle-system. This system uses 24-points in the back side of the mirror that are all resting on small counter-weights and side support is 10-points Boll link Flexible type with 2 Lasalle type. The mount is wheel & disk type Alt-Azimuth design using DC-servo motors. External high accuracy encoder has 47,600 sine-waves/rot. These encoders are used to make real-time corrections on all gearing errors.

• Journal of the Korean Professional Engineers Association
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• v.34 no.4
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• pp.41-47
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• 2001

The paper describes SR3 (Synchronous Round Robin with Reservations), a collision-free medium access control protocol for all-optical slotted packet networks based on WDM multi-channel ring topologies where nodes are equipped with one fixed-wavelength receiver and one wavelength-tunable transmitter SR3 is derived from the SRR and MMR protocols previously proposed by the same authors for the same class of all-optical networks. SRR and MMR already achieve an efficient exploitation of the available bandwidth, while guaranteeing a throughput-fair access to each node. SR3, In addition, allows nodes to reserve slots. thereby achieving a stronger control on access delays; it is thus well suited to meet tight delay requirements, as it is the case for multimedia applications. Simulation results show that SR3 provides very good performance to guaranteed qualify traffic, but also brings signigicant performance improvements for best-effort traffic. Energy effciency is an important issue for optical network since they must rely on their batteries. We present a novel MAC protocol that achieves a good energy efficiency of optical interface of the network and provides support for diverse traffic types and QoS. The scheduler of the base station is responsible to provide the required QoS to connections on the optical link and to minimise the amount of energy spend by the High speed Network. The main principles of the MaC protocol are to avoid unsuccessful actions, minimise the number of transitions , and synchronise the mobile and the base-station. We will show that considerable amounts of energy can be saved using these principles.

• Journal of the Korean Institute of Navigation
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• v.12 no.1
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• pp.113-136
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• 1988

Decision Science or Decision Analysis can be described as a scientific methodolog to provide suitable quantitative information for the decision maker to be able to selected the best feasible alternative on the given decision environment and thus we can say that where there are decision problems, there needs the decision analysis to be applied to them. International shipping is generally said to be the cheapest and most widely used means of transport in international trade and each of the hundreds of seaport. So far as the decision makings in the shipping and port transportation are concerned, of real importance is to understand what the decision problems in each of shipping and port transportation really are and to recognize the meaning of relevance between shipping and seaport in the outworn phrase, that is to say, "The chain is as strong as its weakest link." This paper is intended to present a literature survey on the applied decision analysis to shipping and port transportation problems which have actually been involved in the wide variety of decision environment. At first, the author suggests four divisional framework such as decision analysis in each field of Shipping Economics, Management and Operations of Shipping, Port Economics, and Port Operation and Management, according to the main concern of the decision environment, and then the literature surveys on those four major divisions are described including the problems and solution approaches in each case. The author concludes the paper with the comment on the need of joint research around this area by citing the phrase of "a process of updating the decision makers' intuitions."s' intuitions."quot;

• Journal of the Korean Society for Railway
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• v.10 no.2 s.39
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• pp.96-102
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• 2007

This paper presents a study on the control of a power quality compensating equipment of electrical railway built in small-scaled to preliminary research. Because this compensating equipment is very complicated power electronics system, consisting of a scott transformer as a power source, four single phase inverters interconnected with DC-link capacitors and various electrical apparatuses, multiple controllers and control algorithms with high performance and reliability are needed. The major function of the compensating equipment is to manage reactive and active powers by using the four single phase inverters, so, the main control effort is focused on the power flow control which realized through the decoupling current control of the four inverters. Overall control system is designed with object oriented and analyzed on a Simulink window. The simulation results show that the design scheme is very effective for a complicated control system and the proposed controller has good performance.

• Journal of the Korea Safety Management & Science
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• v.18 no.1
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• pp.227-236
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• 2016

Main purpose of this study is to provide some basic data necessary to research, education, and policy to cultivate professional talents, by investigating what competencies needed to hospital administrative staffs and managers in performing their jobs in the global age. A survey was conducted through self-administered questionnaires for hospital administrative staffs and managers including first-line hands-on workers who were working in 77 hospitals located in Busan, Keongnam, Ulsan areas in South Korea. Major results are as follows: (a) The analysis for the competencies needed to hospital administrative staffs and managers in order to perform successfully their jobs revealed that interpersonal competency, knowledge of management skills in healthcare field, understanding ability for healthcare, in that order of importance, had significant influence on performing their jobs. (b) Regarding the analysis for the detailed competencies necessary to hospital administrative staffs and managers in order to perform successfully their jobs revealed that problem-solving ability, sense of responsibility, positive attitude, leadership, in that order of importance, had significant influence on performing them. This study suggests that universities opened courses related to health care management should newly open a subject 'problem-solving ability in health care' to link with health care field and their curriculums are necessary to change over to practice-oriented curriculum system.

• Journal of Technology Innovation
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• v.13 no.2
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• pp.45-70
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• 2005

Much work on innovation has focused on the manufacturing sector. In this paper, we propose a framework for analyzing innovation in services centred on capability and technology integration. We illustrate the theoretical points made by conducting a case study on an international telephone communications provider Brastel, which introduced significant innovations in international calling services, in the form of rechargeable pre-paid calling card, through effective application of standard IT. Brastel is situated against its main competitors, considering two dimensions of price and service breadth and convenience. A novel technique for measuring competitiveness based on price and service index is introduced. The following competitors were selected: NTT, KDDI, Japan Telecom, Fusion Communications, J-Call / World Link, G-Call, ASP Check, Primus, QuickPhone, and MCI. To create the service index, factors such as ease of use, convenience, number of languages in which the services are available, and additional features were taken into account. The company itself and the rechargeable card innovation were analyzed through in-depth interviews and data collection. It was shown that a competitive advantage was maintained through internal and external capabilities.

• Journal of Korean Medical classics
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• v.22 no.4
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• pp.39-42
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• 2009

Jeongji(情志) in Chinese medicine refers to a series of psychological activity which is expressed as hui(喜), no(怒), wu(優), sa(思), bi(悲), gong(恐), gyeong(驚), together with emotion, sentiment, and cognition, which are manifested as responses of the human body to environmental changes both inside and outside. Sa(思) is a major cognitive activity, and the other six emotions are main emotional activities. The emphasis on the interrelationship between cognition, sentiment, and emotional activity is a unique characteristic of the Jeongji(情志) concept in China. Jeongji[Mental] disorder refers to a series of diseases that has a close link between the attack, clinical presentation and emotional stimulation. The attack is deeply affected by emotional stimulation, with which physical symptoms are either present or absent. However, emotional changes are clear most of the time, their effect on disease development noticeable as well. To sum up, Jeongji[Mental] disorder is related to a wide range of medical problems in fields such as internal, surgical, gynecology, pediatrics, and various psychiatric disorders, not to mention contemporary psychological disorders, neurosis, and all kinds of mental illnesses of today. Moreover, the mental and physical disorders of today all share a common pathogenesis, clinical manifestation and treatment discipline. All the more reason for deeper professional research.

• Journal of Communications and Networks
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• v.7 no.3
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• pp.337-352
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• 2005

In this paper, a fuzzy logic implementation of the random early detection (RED) mechanism [1] is presented. The main objective of the proposed fuzzy controller is to reduce the loss probability of the RED mechanism without any change in channel utilization. Based on previous studies, it is clear that the performance of RED algorithm is extremely related to the traffic load as well as to its parameters setting. Using fuzzy logic capabilities, we try to dynamically tune the loss probability of the RED gateway. To achieve this goal, a two-input-single-output fuzzy controller is used. To achieve a low packet loss probability, the proposed fuzzy controller is responsible to control the $max_{p}$ parameter of the RED gateway. The inputs of the proposed fuzzy controller are 1) the difference between average queue size and a target point, and 2) the difference between the estimated value of incoming data rate and the target link capacity. To evaluate the performance of the proposed fuzzy mechanism, several trials with file transfer protocol (FTP) and burst traffic were performed. In this study, the ns-2 simulator [2] has been used to generate the experimental data. All simulation results indicate that the proposed fuzzy mechanism out performs remarkably both the traditional RED and Adaptive RED (ARED) mechanisms [3]-[5].

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.6
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• pp.2670-2685
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• 2020

Flying ad-hoc networks (FANETs) is a vibrant research area nowadays. This type of network ranges from various military and civilian applications. FANET is formed by micro and macro UAVs. Among many other problems, there are two main issues in FANET. Limited energy and high mobility of FANET nodes effect the flight time and routing directly. Clustering is a remedy to handle these types of problems. In this paper, an efficient clustering technique is proposed to handle routing and energy problems. Transmission range of FANET nodes is dynamically tuned accordingly as per their operational requirement. By optimizing the transmission range packet loss ratio (PLR) is minimized and link quality is improved which leads towards reduced energy consumption. To elect optimal cluster heads (CHs) based on their fitness we use k-means. Selection of optimal CHs reduce the routing overhead and improves energy consumption. Our proposed scheme outclasses the existing state-of-the-art techniques, ACO based CACONET and PSO based CLPSO, in terms of energy consumption and cluster building time.

• Proceedings of the Korean System Dynamics Society
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• 2000.07a
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• pp.65-102
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• 2000

In 1987, The Brundtland Report defined a sustainable development as the development that meets the needs of the present without compromising the ability of future generations to meet their own needs. This is the concept that we should cling to, to preserve natural resources of the present for the future generation. With this concept in mind, this paper criticized that the current waste management policy has been neglecting resource preservation aspect of waste management policy while giving too much emphasis on reducing waste generation. Thus, the purpose of this paper is to analyze how waste management policy can affect preservation of natural resources, and to investigate policy alternatives that can reduce both the volume of waste generated and the amount of natural resources that need to be consumed in the production process. The study was conducted based on the literature survey and system dynamics simulation. Borrowing Randers and Meadows's solid waste model with some modification of parameter and variables, this paper simulate several policy alternatives to figure out the most effective waste management policy set that can meet the need of the present without compromising the ability of the future generation to meet their own needs. Main concern was how to link waste management policy with resource management policy that can lead to minimization of waste generation and resource consumption.