• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.641-645
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• 2008

In this paper, vibration sources of the BLOC motor are identified and the motor vibrations are reduced by structural modification. For vibration characteristic identification, vibration signals measured by an accelerometer when the BLOC motor is moving. These signals are presented in a waterfall plot in order to find the dependency of frequency components on the motor speed. It is found that main vibration source is BLOC motor test rig. From finite element analyses and some experiments, it is also found that resonances occur because the natural frequencies of the test rig exist in usual driving speed rang. To shift the natural frequencies outside the driving rang, the test rig is modified increase stiffness. It is verified that considerable amount of vibration are reduced by the structural modification.

• Environmental Engineering Research
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• v.10 no.1
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• pp.15-21
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• 2005

A computer program is developed for the prediction of the flow pattern and the removal efficiency of suspended solid (SS) in a circular secondary clarifier. In this study the increased density effect by SS on hydrodynamics has been systematically investigated in terms of Froude Number (Fr), baffle existence, and a couple of important empirical models associated with the particle settling and Reynolds stresses. A control-volume based-finite difference method by Patankar is employed together with the SIMPLEC algorithm for the resolution of pressure-velocity coupling. The k-ε turbulence and its modified version are incorporated for the evaluation of Reynolds stresses. The calculation results predicts well the overall flow pattern such as the waterfall phenomenon at the front end of the clarifier and the bottom density current with the formation of strong recirculation especially for the case of decrease of Fr. Even if there are some noticeable differences in the prediction of two turbulence models, the calculated results of the radial velocity profiles are generally in good agreement against experimental data appeared in open literature. Parametric investigation has been systematically made with the Fr and baffle condition with detailed analysis.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.05a
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• pp.207-210
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• 2004

Waterfall 모델에서의 소프트웨어 개발 단계는 사용자로부터 요구 사항을 정의하고, 이것이 다음 단계의 input 이 되어 개발자에 의해 작업이 진행되는 개발 양식을 따른다. 시스템 요구 사항을 정의할 때에, 프로세스 관점에서 사용자 업무를 이해하고, 이 프로세스에서 사용되는 시스템과의 관계를 정의하여 요구 사항으로 함께 정의한다면, 단순한 시스템의 기능을 정의하여 개발하는 것 보다 시스템의 사용 목적을 이해하고 개발하게 됨으로써, 더 만족도 높은 시스템으로 개발할 수 있게 된다. 프로세스 관점에서 이해하고 정의하는 시스템의 요구 사항은 시스템 보수 작업(Maintenance)시에도 시스템의 상황이 현재 업무 프로세스와 어떻게 연계되어 있는지 파악하기 용이하고, 테스트 단계에서도 테스트 조건이나 테스트 시나리오로서도 활용이 가능하다. 새로운 업무를 담당하는 사람에게도 시스템 개발 요구 사항에서 정의된 업무 프로세스 맵(Map)이 관련 업무를 파악할 수 있는 기초 자료로 재 활용 될 수도 있다. 비즈니스 프로세스 리엔지니어링에서 사용하는 비즈니스 프로세스 맵핑(Mapping) 기술을 소프트웨어 개발 방법론에 적용하여, 요구 분석 단계에서 사용하는 분석 도구로서의 응용을 제안하고자 한다.

• International Journal of Advanced Culture Technology
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• v.8 no.4
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• pp.189-199
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• 2020

We aimed to understand various problems identified at waterscape facilities of gardens built at garden shows in Korea. The main purpose of the study is to understand which parts of waterscape facility built in gardens at garden shows are causing problems and whether these problems can be traced back from garden design phase or from local communities in charge of maintenance. Furthermore, we examined if such problems get more aggregated as time passes by and different garden shows have different types of problems. In this study, types of waterscape facilities examined are pond, waterway, wall fountain, water glass, trough, mist, Cascade, fountain, rain garden, waterfall. An analysis of the maintenance status of waterscape facilities introduced in the existing gardens confirmed that problems could arise in two main respects. One is due to poor maintenance by the organizers of the garden show, and the other is due to the poor design of waterscape facilities by the garden designer.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.2
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• pp.266-274
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• 2021

Ship officers are subject to excessive job stress, which has negative physical and psychological impacts and may adversely affect the smooth supply and demand of human resources. In this study, a mobile web application was developed as a tool for systematic job stress measurement and management of officers and verified through quality evaluation. Requirement analysis was performed by ship officers and staff in charge of human resources of shipping companies, and the results were reflected in the application configuration step. The application was designed according to the waterfall model, which is a traditional software development method, and functions were implemented using JSP and Spring Framework. Performance evaluation on the user interface, confirmed that proper input and output results were implemented, and the respondent results and the database were configured in the administrator interface. The results of evaluation questionnaires for quality evaluation of the interface based on ISO/IEC 9126-2 metric were significant 4.60 for the user interface and 4.65 for the administrator interface in a 5-point scale. In the future, it is necessary to conduct follow-up research on the development of data analysis system through utilization of the collected big-data sets.

• Journal of Information Technology Services
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• v.20 no.1
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• pp.41-54
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• 2021

The SW-centered battlefield management information system R&D project takes a long period of 5-10 years or more by applying a complex and rigid batch acquisition strategy. In order to solve this problem, it is necessary to institutionalize a rapid and flexible battlefield management information system R&D project management procedure applying agile development methodology, and a government project management organization and contract management method to support it In this study, we analyzed the case of applying the Agile development method centered on Scrum to the US SW-centered weapon system R&D project and the characteristics and problems of the battlefield management information system R&D project in Korea, and suggested improvement measures as follows. First, the battlefield management information system R&D model applies the hybrid development method, and the system requirements analysis and system structure design use the existing waterfall development procedure, and the agile method is applied from the SW requirements analysis to the system integration stage. Second, flexible adjustment of performance, schedule, and cost by organizing an Agile IPT in which military (requirements) - DAPA (project management) - developer - functional specialized organizations (test and evaluation, quality, government research institutes, etc.) participate. Third, improving the Basic Order Agreement so that it can be applied to agile R&D.

• The Korean Journal of Health Service Management
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• v.7 no.3
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• pp.203-212
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• 2013

Medical devices separated by a committee of the International Electrotechnical Commission IEC TC (Technical Committee) 62 medical electrical equipment being promoted by the International standards. Actually, a lot of standards were existed, but many national and international standards for medical devices were lacking in practical standards that can be applied to their development. Most international standards were focused in electrical and mechanical safety of medical devices. Therefore, there were few practical standards which contain essential performance evaluation. Although medical device regulations do not enforce a fixed lifecycle model, activities are presented in a sequential manner, thus hinting at a waterfall process. Meanwhile, for a decade or more, software teams have benefitted from agile development methods. Several medical device manufacturers have adopted agile practices while keeping development in compliance with regulations, but conflicts arise and decisions have to be taken in favor of agility or formality. However, if there are new practical standards of medical devices, it must be possible to promote the medical devices industry in their nation. To do this, there is a need to develop a new standard could apply to the international market through the analysis of the medical device related technology. Consequently, new standards such as NP (New proposal) or NWIP (New Work Item Proposal) should be developed through international standardization of medical device technology.

• Journal of The Geomorphological Association of Korea
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• v.24 no.1
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• pp.93-104
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• 2017

The objective of this study was two fold: firstly, we analyzed how the Geoparks have been run since the first one had been designated on December 31th, 2015. We then investigated how visitors' geographical and geological recognitions on the parks have changes. We visited geosites and investigated how well these sites accorded with the conditions for running Geoparks. In addition, scenery pictures and hashtags uploaded in Instagram between 2015 and 2016 were collected in order to analyze visitors preferences on the geosites along the, Hantan Imjingang River Geopark. Results showed that the hotspots were Bidulginang Waterall, Art Valley, and Jaein Waterfall. Compared to the ratio of geographical and geological references in 2015, the hashtags in all of these three geosites increased. The increases were as much as 3% in Bidulginang Falls, 0.6% in Art Valley, and 5% in Jaein Falls. In labelling the geographical and geological terms in Bidulginang Falls and Jaein Falls, the most frequently mentioned hashtags was "columnar joint", followed by "natural monument", "Geopark", and "basalt canyon". This study includes the study of visitors recognition which is one of the most important, but somehow neglected factor for the geopark's management.

• Journal of Environmental Science International
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• v.30 no.3
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• pp.267-277
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• 2021

This study investigates sound, scenery, and soundscape preferences, which are sensory factors that users feel in a healing forest, comparing the difference in recovery by the soundscape. In the barrier-free, wooden walking path of the National Daegwallyeong Healing Forest, a survey site with five different conditions was selected. Users prefer water sounds the most and places with open views for scenery. For the complex sensation of soundscapes, the most preferred is a space where water sounds can be heard, and either a waterfall or an open view can be seen. A profile of mood states test was use to compare users' psychological recovery by the soundscape. It was found that users felt the most positive mood with water sounds and open views. In addition, users' preference for artificial sounds, scenery, and soundscape was the lowest. In the mood state test, it was found that the artificial soundscape incited the most negative emotions.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.35 no.1
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• pp.57-67
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• 2017

Based on the study on place name, meaning analysis of buddhist temple Palgyeng, and classifications of instructions and characteristics of writings on rocks, the main results of the study showed the following. Cheongamsa is located in the upstream of Muheulgugok Valley which was run by Hangang Jeong Gu(寒岡 鄭逑), a typical young man in the middle of the Joseon Dynasty, and overlaps with chief monk Byukam Lee Dukjin's(1896~?) object of Cheongamsa Palgyeng during Japanese colonial era. Including the mountain embracing Cheongamsa called Bullyeong-san, various characteristics of writings on rocks such as use of combination of place names including Sudosan, Seonlyeongsan, and Sinseondae, as well as Cheongamsa Temple, Bullyeongdongchun(佛靈洞天), Namuabitabul, Hogye(虎溪), Yeosan Waterfall(廬山瀑布), and Sejinam(洗 塵巖) show co-existence of Confucianism and Taoism mixed together in the temple. Especially for Cheongamsa Valley Hogye and Samsocheon(三笑泉) which is in the precincts of the temple, are realized as the symbol of the scenery of the three religion consilience of Confucianism, Buddhism, and Taoism through announcement using Hogyesamso(虎溪三笑) which originated from Yeosan Donglimsa, Jiangxi, China. Also, there are Yeosan Waterfall with a noble sense of place by negotiating with god, writing on rocks imprinted, and Yeosangyo(廬山橋) in Cheongamsa. As such, cultures of the three religion remain in various layers with the spirit of Hogyosamso symbolizing the consilience and coexistence of the three religion in Cheongamsa without the exclusiveness of Buddhism. Besides, the third precept of Yukhwagyeongbub, known to be practiced in Buddhist temples, which says "Do not only express self-assertion and ignore others" according to the dogma of working together in harmony, is in accordance with the spirits of Hogyesamso. As shown, Gimcheon Cheongamsa which is adorned with cultural landscapes of Hogyesamso, Gugokdongcheon(九曲洞天), and Palgyeng(八景), is not only good enough for the way of Buddhism and Confucianism but also for a place for the three religion consilience embracing the three religion.