• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.10
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• pp.1275-1282
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• 2012

Helicopter rotor systems are dynamically loaded structures with many composite components such as the main and the tail rotor blades. The fatigue properties of composite materials are extremely important to design durable and reliable helicopter rotor blades. The safe-life methodology has generally been used in the helicopter industry to substantiate dynamically loaded composite components. However, it cannot be used to evaluate the strength reducing effects of flaws and defects that may occur during manufacturing and operational usage. The damage tolerance methodology provides a proper means to overcome this shortcoming; however, it is difficult to economically apply it to every composite component. The flaw tolerant methodology is an equivalent option to the damage tolerance methodology for civil and military rotorcraft. In this study, the flaw tolerant safe-life evaluation is described and illustrated by means of successful application to substantiate the retirement time of composite rotor blades.

• Journal of the Earthquake Engineering Society of Korea
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• v.15 no.6
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• pp.55-66
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• 2011

The purpose of this study was to develop an efficient process in the design and construction of a 1:5 scale 10-story R.C. apartment building model for an earthquake simulation test. The reduction ratio of the specimen was determined by the size ($5m{\times}5m$) and pay load (600kN) of the available shaking table and the availability of model reinforcements. For efficiency and quality control of the reinforcement work, prefabrication was used. Construction was conducted in two steps, the wall in one step, and another step for the slab, because it was impossible to remove the formwork of a wall if the walls and slabs in a story were constructed in one step. The slip form construction method was used repetitively for walls. The formwork of a wall was made with veneer and acryl plate on each side, so it was possible to check the quality of the concrete placing. To construct this model, it took roughly six months with five full-time research assistants, for a total of 602 man days of labor in construction.

• Journal of Navigation and Port Research
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• v.29 no.1 s.97
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• pp.91-96
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• 2005

The National Marine Electronics Association(NMEA) is nonprofit-making cooperation composed with manufacturers, distributors, wholesalers and educational institutions. We use the basic port of equipment in order to process the signal from NMEA signal using equipment. When we don't have enough one, we use the multi-port for processing. However, we need to have module development simulation which could multiplex and provide NMEA related signal that we could solve the problems in multi-port application and exclusive equipment generation for a number of signal. For now, we don't have any case or product using NMEA multiplexer so that we import expensive foreign equipment or embody NMEA signal transmission program like software, using multi-port. These have problems since we have to pay lots ci money and build separate processing part for every application programs. Besides, every equipment generating NMEA signal are from different manufactures and have different platform so that it could cause double waste and loss of recourse. For making up for it, I suggest the NMEA multiplexer embodiment, which could independently move by reliable process and high performance single hardware module, improve the memory efficiency of module by designing the optimized Queue, and keep having reliability for realtime communication among the equipment such as main input sensor equipment Gyrocompass, Echo-sound, and GPS.

• Journal of Korea Water Resources Association
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• v.32 no.3
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• pp.281-289
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• 1999

Small-scale hydropower projects at existing agricultural reservoirs can contribute to produce electric energy by maximizing the use of releases from the reservoirs. The irrigation water duration, the reservoir hydropower simulation, and the nonlinear programming model are employed to estimate potential hydroelectric energy at an existing reservoir. The nonlinear programming model consists of finding a maximum hydroelectric energy subject to irrigation water demand constraints. The sample reservoir given a set of inflow and irrigation water is considered. The optimal solutions by the optimization model yield the most hydroelectric energy for the analysis period in the three methods. Consequently, the nonlinear programming model uses the most water for hydropower generation with respect to the total inflow of the sample reservoir. It is also found that additional storage by increasing the normal water level of the sample reservoir does not significantly increase the annual hydroelectric energy for the given reservoir. It is expected that the optimization model and the proposed procedure for estimating potential hydroelectric energy can be applied to evaluate feasibility analysis for small scale hydropower additions at existing agricultural dams.

• Clean Technology
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• v.23 no.2
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• pp.121-132
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• 2017

The increase of greenhouse gases and the concern of global warming instigate the development and spread of renewable energy and hydrogen is considered one of the clean energy sources. Hydrogen is one of the most elements in the earth and exist in the form of fossil fuel, biomass and water. In order to use hydrogen for a clean energy source, the hydrogen production method should be eco-friendly and economic as well. There are two different hydrogen production methods: conventional thermal method using fossil fuel and renewable method using biomass and water. Steam reforming, autothermal reforming, partial oxidation, and gasification (using solid fuel) have been considered for hydrogen production from fossil fuel. When using fossil fuel, carbon dioxide should be separated from hydrogen and captured to be accepted as a clean energy. The amount of hydrogen from biomass is insignificant. In order to occupy noticeable portion in hydrogen industries, biomass conversion, especially, biological method should be sufficiently improved in a process efficiency and a microorganism cultivation. Electrolysis is a mature technology and hydrogen from water is considered the most eco-friendly method in terms of clean energy when the electric power is from renewable sources such as photovoltaic cell, solar heat, and wind power etc.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.805-810
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• 2002

Development of tenderizer using domestic fruits was studied. Kiwifruit was dried using various methods, and the quality of kiwifruit powder was observed during 12 week storage. Frozen kiwifruit was prepared in paste, dice, and whole flesh. After drying, paste-type kiwifruit showed 2.0 and 1.3 times higher proteolytic activity than dice and whole flesh kiwifruits, respectively. Nine hour of hot-air drying or 46 h of freeze-drying eliminated more than 90% of water from kiwifruit, during which discoloring of kiwifruit occurred. Freeze-dried powder showed 6.6 times higher yield and proteolytic activity, and resulted in almost no discolorization than those of air-dried powder. Addition of bulking agent affected the quality of hot air-dried kiwifruit powder, except color, resulting in $3.2{\sim}3.6$ times higher proteolytic activity than that without bulking agent, which is comparable to 60% of the initial freeze-dried powder content. Moisture content of kiwifruit powder with bulking agent sustained consistently during 12 week storage, whereas proteolytic activity decreased for the first 4 weeks. Freeze-drying is a preferable method to produce kiwifruit powder for tenderizer, although hot air-drying with bulking agent treatment is more economical.

• Journal of Information Management
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• v.8 no.5
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• pp.130-140
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• 1975

이용자(利用者) 중심(中心)의 대화방식(對話方式) 시스팀을 개발(開發)하고 시험(試驗)하였다. 2년(年)동안 280개의 프로파일로 CA - Condensates 데이터 베이스내에서 정보(情報)를 검색(檢索)해 보았다. 그 시스팀의 작업능률(作業能率)을 사용(使用)한 데이터 베이스와 하드웨어의 구조(構造), 소프트웨어 패키지, 이용자(利用者)의 수(數), 그리고 정보(情報)센터에서 제공(提供)한 보조(補助)에 따라 평가(評價)하였다. 대화식(對話式) 검색방법(檢索方法)이나 이용자(利用者)의 요구(要求)를 양화(量化)하는 것, 그리고 여러가지 분야별(分野別)로 검색(檢索)하는 방법(方法) 등 이용자(利用者)의 요구(要求)를 보다 충실(充實)하게 만족(滿足)시킬 수 있는 여러가지 방법(方法)들을 논의(論議)하였다. 모든 정보(情報)시스팀의 목적(目的)은 적시(適時)에 올바른 정(情)보를 적자(適者)에게 제공(提供)하는 것이라고 잘 알려져 있다. 다시 말해서, 정보(情報)시스팀의 주요목적(主要目的)은 이용자(利用者)의 요구(要求)를 충족(充足)시켜 주는 것이다. 이러한 관념(觀念)의 변화(變化)는 정보처리(情報處理)에 큰 변화(變化)를 가져와 정보(情報)시스팀의 적응성(適應性)을 증가(增加)시키기 위해 여러 가지 새로운 방법(方法)들이 개발(開發)되었다. 정보(情報)시스팀들 사이의 상호작용(相互作用), 사람과 컴퓨터와의 대화(對話), 그리고 컴퓨터의 조력(助力)으로 이용자(利用者)의 프로파일을 작성(作成)하는 것 등은 이용자(利用者)의 요구(要求)를 존중(尊重)하고, 필요(必要)한 정보(情報)를 쉽게 찾기 위해서 고안(考案)된 것이다. 한편, 우리들은 이용자(利用者)의 특성(特性)이나 배경(背景), 그리고 문헌(文獻)에 대한 그의 습성(習性) 등에 대해서 얼마나 모르고 있는가를 깨닫게 된다. 상기(上記)의 내용(內容)을 요약(要略)하면, 근대정보(近代情報) 시스팀은 다음의 필요조건(必要條件)을 만족(滿足)해야 한다. 1) 이용자(利用者)의 요구(要求)에 호응(呼應)하기 위해서 적합(適合)한 일련(一連)의 정보(情報)를 제공(提供)해야 한다. 2) 이용자(利用者)와의 관계(關系)에서 시스팀은 적극적(積極的)이어야 한다. 즉, 프로파일 검색공식(檢索公式)에서 유발(誘發)되는 잘못을 지시(指示)하고 지적(指適)할 수 있어 야 한다. 나아가서 컴퓨터의 조력(助力)으로 프로파일을 작성(作成)하고 쉽게 수정(修正)할 수 있는 바람직하다. 우리들은 상기(上記)한 필수조건(必須條件)에 일치(一致)하도록 노력(努力) 하고 Bratislava에 위치(位置)하고 있는 슬로박 과학원(科學院)의 무기화학연구소(無機化學硏究所)와 화학공업경제연구소(化學工業經濟硏究所)가 공동(共同)으로 개발(開發)한 시스팀이 상기(上記)의 특수성(特殊性) 최소(最少)한 몇가지 도입(導入)하였다. 시스팀은 CACS라는 작업명하(作業名下)에서 운영(運營)되었다. 대략 15개월동안 280여개의 프로파일로 CA- Condensates 데이터베이스에서 정보(情報)를 검색(檢索)하여 이용자(利用者)들에게 최신정보(最新情報) 주지사업(周知事業)을 해 보았다. 우리들은 시스팀의 작업능률(作業能率)을 평가(評價)하고 이용자(利用者)의 요구(要求)를 만족(滿足)시키는 최선(最善)의 방법(方法)을 모색(摸索)하였다. 우선 이용자(利用者)와 시스팀사이를 밀접(密接)하게 연결(連結)하는데 중점(重點)을 두었다. 작업능률(作業能率Z)을 분석(分折)해 보고 우리들은 효율(效率)에 영향(影響)을 주는 인자(因子)는 다음의 4가지 주요분류(主要分類)에 속한다는 결론(結論)을 얻었다. (1) 검색(檢索)하는 데이터 베이스 (2) 情報시스팀, 소프트웨어 패키지 그리고 하드웨어 구조(構造) (3) 이용자(利用者)의 특성(特性)과 그의 요구(要求) (4) 정보(情報)센터가 이용자(利用者)에게 제공(提供)하는 보조(補助)

• Korean Journal of Organic Agriculture
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• v.28 no.4
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• pp.591-604
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• 2020

The objectives of this study were to find out the best condition of extracting methods of limonene from citron and to determine effects of limonene on immune modulation activity by measuring cytokine secretion using RAW 264.7 mouse macrophage cells. When distilled water was used as a solvent instead of organic solvents to extract limonene from citron, addition of refluxing process to simultaneous steam distillation extraction method was found to be much effective in extracting limonene. However, it required longer extraction time than using other organic solvents. Limonene extracts showed increased IL-β and IL-6 but decreased the TNF-α gene expression in limonene concentration dependant manner. However oral administration of limonene extracts to mice did not influence significantly compared to control in in vivo experiment. It might be due to that the mice were kept in well controlled and complete environment. Limonene, a natural material from citron has been approved to have a immune-modulation activity in the present study and have a potential as a feed additive that is environmentally friendly and no harmful. Further study with protected limonene, for example, for the protection of limonene from oxidation or bypass the ruminal degradation in order consequently to increase immune-modulation activity might be useful as a further research.

• International Area Studies Review
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• v.15 no.3
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• pp.471-491
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• 2011

This study is to analyze the determinants of inflow FDI with panel data of 12 provinces in western region of China for the period, 1990-2007, from the perspective of market-oriented FDI and production-efficiency-oriented FDI. The empirical findings are following. First, the empirical results prior to the start of western development program show that the GRDP, the intense of industrialization and university graduates per 10,000 residents have positive coefficient signs at the significant level, while wage level has a negative and significant value. Second the empirical results using the data after the launching of the western development program show that the GRDP, the intense of industrialization have positive relations with FDI, while openness in terms of the ratio of international trade to GRDP and the wage level have negative coefficients. Finally, this thesis finds that the empirical results for both periods are very similar, which suggest that the economic structure in western region has not changed significantly even though almost a decade passed since the western development program launched.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.2
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• pp.5-12
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• 2019

The study is carried out to survey the proper management and to propose an eco - friendly separation system through efficient screening and resource recovery of excavated materials containing waste from various excavating fields such as reconstruction of landfill sites for reuse, reclamation of unsanitary landfill and residential land development of waste dumping sites. The current status and screening process and analytical characteristics of the excavated materials containing waste were reviewed. Through the analysis of the samples such as separated combustibles, recyclable soils and residues collected from the on-site visits we were able to understand the characteristics of separated materials and excavated materials containing waste such as calorific value, elementary composition, TOC, foreign material content and LOI. It has been found that elimination of the moisture of excavations, removal of attached soil from the surfaces of the excavated combustibles and the quantitative supply method of the input devices are the main operating factors as essential factors for the optimal separation of excavated materials containing waste. For efficient management and recycling of excavated materials containing, it is necessary to set criteria of ash content in separated combustibles and criteria organic matter content in separated soils.