• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.8
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• pp.1095-1101
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• 2002

An experimental apparatus was prepared to investigate thermal and hydrodynamic characteristics of regenerator at cryogenic temperature under pulsating pressure condition. The regenerator was pressurized and depressurized by a compressor with various operating frequencies. Cold end of the regenerator was maintained around 100 K by means of a liquid nitrogen heat exchanger. Instantaneous gas temperature and mass flow rate were measured at both ends of the regenerator during the whole pressure cycle. Pulsating pressure drop across the regenerator was also measured to see if it could be predicted by a friction factor at steady flow condition. The operating frequency of pressure cycle was varied between 3 and 60 Hz, which are typical operating frequencies of Gifford-McMahon, pulse tube, and Stilting cryocoolers. First, the measured friction factor for typical wire screen mesh regenerator was nearly same as steady flow friction factor for maximum oscillating Reynolds number up to 100 at less than 9 Hz. For 60 Hz operations, however, the discrepancy between oscillating flow friction factor and steady flow one was noticeable if Reynolds number was higher than 50. Second, the ineffectiveness of regenerator was directly calculated from experimental data when the cold-end was maintained around 100 K and the warm-end around 293 K, which simulates an actual operating condition of cryogenic regenerator. Influence of the operating frequency on ineffectiveness was discussed at low frequency range.

• Journal of Korean Society of Rural Planning
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• v.1 no.1
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• pp.89-98
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• 1995

This paper is intended to review the major problems of rural settlement development and attempts to find the direction to enhance the effectiveness of rural settlement development policies and strategies. Small amount of financial resources being mobilized, similar policies for rural settlement development have been implemented sectionally by the respective sectoral goverment bodies. It has resulted in a lot of coulict and ineffectiveness in the process of rural settlement development To rationalize the rural settlement development, there should be some change in the current practice of the project: integration of development efforts, consideration of regional situation and settlement system, and introduction of principles and criteria suitable for rural settlement planning.

• Journal of Environmental Impact Assessment
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• v.17 no.1
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• pp.11-24
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• 2008

The Korea Environmental Impact Assessment (EIA) system was introduced in 1977 through the Environmental Conservation Act. It has progressed through many laws and regulations promoting the balance between development and conservation, and functioning as a Preventitive environmental policy. Despite the efforts to minimize environmental damage from development and to uplift social awareness of environmental preservation, deficient impartiality and objectivity in completing and investigating environmental assessments, there have continously existed conflicts among related stakeholder, neglecting arrangements and ineffectiveness of public participation. This research present EIA obstacles and analyzes the overall status of the EIA through surveys from related experts. On the basis of this research, the actual complications regarding the developer, public participation, examiner and consultant are brought about. Also, remedies are proposed to ensure effective EIAs and restore confidence in them.

• Journal of the Korean Society of Safety
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• v.30 no.1
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• pp.1-7
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• 2015

This study first addresses the ineffectiveness of indirect regulation on industrial machines. Analysis of causes of industrial accidents associated with industrial machines further reveals the fact that technical causes need to be resolved at the manufacturing stage to reduce the frequency and strength of industrial accidents. Balanced safety certification on manufacturers and safety inspection on users of industrial machines are then suggested to effectively resolve such technical causes. The effectiveness of such safety certification and safety inspection can be justified by cost-benefit analysis. Particularly, balance in expected benefits of safety certification and safety inspection is a key issue for validity of such analysis. The accumulated benefit-costs for press brake and portable sawing machine confirm the effectiveness of such safety system.

• Journal of Engineering Education Research
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• v.18 no.2
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• pp.65-76
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• 2015

Despite its ineffectiveness, the dominant pedagogy for engineering education is still "chalk & talk". Meanwhile, student-centered learning models have been highlighted for strong communication, teamwork skills, deep understanding and analysis on social, environmental and economic issues as well as application of their engineering knowledge in practice. Among others, on problem- and project-based learning, this article examines theoretical background and detailed features and a comparison between both learning models including common and different features from the previous theoretical and empirical studies. It reviews some cases of where they have been practiced successfully in engineering, and further, applied strategies for engineering education are suggested.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.5
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• pp.165-171
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• 2000

To get smoother ground surface, it is required to replace the grinding wheel with a finer-grit wheel. When the operator replaces the grinding wheel, the balancing and dressing of the wheel surface are necessary. So this replacement has a lot of problems like inconvenience to operators, delays in the operation time, and ineffectiveness in the production process. Therefore, a laminated grinding wheel, which consists of three layers, is provided. The side layers are coarse grits and the middle layer is made up of fine grits. To show the effectiveness of the laminated grinding wheel, experiments on the surface roughness and the material removal rate were performed respectively. As a result, it was found that the grinding process using a laminated grinding wheel can generate smoother ground surface in shorter time.

• Journal of Preventive Medicine and Public Health
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• v.26 no.4 s.44
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• pp.480-507
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• 1993

Environmental pollution is common problem of the present world that is intimately related to the future survival of human beings. The problems of environmental pollution originate from the pursuit of benefit by enterprises, insufficient countermeasure of government and ignorant life style of the people. Health hazards due to environmental pollution have characteristics of irreversibility, difficulty in measurement and ineffectiveness of personal prevention. Objects of this article are to review the various aspects of environmental pollution, to outline the present status of environmental pollution and strategy to control environmental pollution in Korea. In the first part of this article, causes of environmental pollution are presented. International relationships, world-wide status of environmental pollution and health hazards due to environmental pollution are briefly reviewed. In the second part, present status of air, water, soil and ocean pollution in Korea is presented. Pollution by radioactive materials, noise, vibrations, odor, wastes and chemicals is reviewed. Climate changes related to environmental poisoning, problems of workplace environment, pesticide and defoliants are also reviewed. Finally, control measures for environmental pollution including the role of government are reviewed.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.8 no.1
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• pp.33-37
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• 1997

Incomplete glottic closure of vocal cord atrophy is the common cause of dysphonia. Patients with vocal cord atrophy have complaints such as dysphonia, vocal fatigue, abnormal sensation in the throat, laryngeal pain, cough or sputum like functional voice disorders. Many investigators could not confirm the pathologic laryngeal structure because of their minute pathology. But recent advancements of laryngeal examinations made the many clinicians to detect minimal laryngeal pathology and to have mind the treatment for the vocal cord atrophy. But the results were less effective than their thoughts, the reasons of ineffectiveness were not known well. Authors have found the Hyperfunctional movement of the supraglottis during phonation before and after thyroplasty type I for vocal cord atrophy. Then we have applied the combined modality treatment with thyroplaty type I and voice therapy for relieve of hypefunctional movement of the supraglottis. These options have had more imporved results.

• Korean Management Science Review
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• v.15 no.2
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• pp.161-175
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• 1998

As organizations have come to be more complex and diverse, management has come to spend an increasing proportion of its time and efforts in handling organization conflict. Moreover, organizational conflict problems are often not recognized until the balance of interests is destroyed or a radical organizational change such as BPR takes place. Once an organizational conflict arises, however, it reduces corporate synergy seriously, leading to organizational ineffectiveness. Therefore, it is important to identify the cause of organizational conflict in advance and resolve it based on the proper diagnosis as early as possible lest it should undermine the organizational effectiveness. We propose a method that facilitates diagnosing potential organizational conflict and determining appropriate strategy to the conflict, based on the analysis of cognitive maps. To support the application of the method in the real world context, a computerized tool is introduced. The working procedures of the method and the features of the tool are illustrated with their application to the real case of the cable TV home shopping company.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.4
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• pp.623-629
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• 2003

This study is about the development of a system related to the CATV network. It intends to develop an automatically centralized Headend system and a distributive system to remove the ineffectiveness of the established manual system. To achieve this goal, we took a pan of bandwidth, which is not used for the transmission of video signals in the established frequency bandwidth, and used it for the transmission and receiver of controlling signals. By this way we could design a system of transmission and receiver and a automatic distributive system. We developed an information management system for the 9600bps CATV using RS-232 of forward/backward communication and backward communication.