• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2009년도 학술발표회 초록집
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• pp.752-757
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• 2009

In the last decade, many methods such as greet chamber, reservoir, or debris barrier, have been utilized to manage and prevent muddy water problem. The Vegetative Filter Strip (VFS) has been thought to be one of the most effective methods to trap sediment effectively. The VFS are usually installed at the edge of agricultural areas adjacent to stream or drainage ditches, and it has been shown that the VFS effectively removes pollutants transported with upland runoff. But, if the VFS is installed without any scientific analysis of rainfall-runoff characteristics, soil erosion, and sediment analysis, it may not reduce the sediment as much as expected. Although Soil and Water Assessment Tool (SWAT) model has been used worldwide for many hydrologic and Non-Point Source Pollution (NPSP) analysis at a watershed scale. but it has many limitations in simulating the VFS. Because it considers only 'filter strip width' when the model estimates sediment trapping efficiency, and does not consider the routing of sediment with overland flow option which is expected to maximize the sediment trapping efficiency from upper agricultural subbasin to lower spatially-explicit filter strip. Therefore, the SWAT overland flow option between landuse-subbasins with sediment routing capability was enhanced with modifications in SWAT watershed configuration and SWAT engine. The enhanced SWAT can simulate the sediment trapping efficiency of the VFS in the similar way as the desktop VFSMOD-w system does. Also it now can simulate the effects of overland flow from upper subbasin to reflect the increased runoff volume at the receiving subbasin, which is what is occurring at the field if no diversion channel is installed. In this study, the enhanced SWAT model was applied to small watershed located at Jaun-ri in South Korea to simulate diversion channel and spatially-explicit VFS. It was found that approximately sediment can be reduced by 31%, 65%, 68%, with diversion channel, the VFS, and the VFS with diversion channel, respectively.

• Asian-Australasian Journal of Animal Sciences
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• 제29권11호
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• pp.1569-1575
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• 2016

Two experiments were conducted to examine the influence of kaolinite clay supplementation (0%, 1%, or 2% diet dry matter [DM] basis) on characteristics of digestion (Trial 1) and growth performance (Trial 2) in calf-fed Holstein steers fed a finishing diet. In Trial 1, 6 Holstein steers ($539{\pm}15kg$) with ruminal and duodenal cannulas were used to evaluate treatment effects on characteristics of digestion. Kaolinite clay supplementation decreased total tract DM digestion (linear effect, p<0.01) without effects ($p{\geq}0.10$) on site and extent of digestion of organic matter, neutral detergent fiber, starch and N, or ruminal microbial efficiency. There were no treatment effects on ruminal pH, volatile fatty acids molar proportions or estimated methane production. In Trial 2, 108 Holstein steers ($132.4{\pm}5.6kg$) were used in a 308-d study to evaluate growth performance and carcass characteristics. There were no treatment effects (p>0.10) on average daily gain (ADG) and gain efficiency (ADG/dry matter intake). Kaolinite supplementation tended (linear effect, p = 0.08) to increase dietary net energy (NE) during the initial 112-d period. However, the overall (308-d) effect of supplementation dietary NE was not appreciable (p>0.20). However, due to the inertness of kaolinite, itself, the ratio of observed-to-expected dietary NE increased with kaolinite supplementation. This effect was more pronounced (linear effect, $p{\leq}0.03$) during the initial 224 d of the study. Overall (308 d), kaolinite supplementation tended to increase (linear effect, p = 0.07) dietary NE by 3% over expected. Kaolinite supplementation did not affect carcass weight, yield grade, longissimus area, kidney, pelvic and heart fat, and quality grade, but decreased (linear effect, p = 0.01) dressing percentage. It is concluded that kaolinite supplementation up to 2% of diet DM may enhance energetic efficiency of calf-fed Holstein steers in a manner independent of changes in characteristics of ruminal and total tract digestion.

• 한국전자통신학회논문지
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• 제13권1호
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• pp.193-198
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• 2018

현재 제조, 의료, 교육, 물류, 기타 서비스업 등 대부분의 분야에서 전산시스템을 도입하여 업무에 활용하고 있으며 업무의 효율성을 더욱 높이기 위해 모바일 시스템을 도입하는 경우가 늘어나고 있다. 그러나 모바일 애플리케이션의 개발은 안드로이드 애플리케이션을 기준으로 안드로이드에 관한 전문적인 지식이 부족한 일반인 또는 일반 회사의 전산팀원들이 개발하기에 어려움이 있고 결과적으로 작업의 효율성이 떨어지게 된다. 이러한 점에 착안하여 본 논문에서는 아직까지 교육용으로 대부분 사용되고 있는 앱인벤터의 기능을 확장하여 건강 검진 신체계측 데이터 입력용 모바일 앱을 설계하고 개발함으로써 건강검진 데이터 입력 업무에 효율성을 제공하고 동시에 전문적인 모바일 앱 개발에 대한 지식이 부족한 전산담당자에게 앱인벤터를 이용해 쉽고 빠르게 업무용 모바일 앱을 개발해 검진업무를 비롯한 DB관련 업무의 효율성을 높일 수 있을 것으로 기대한다.

• 농업과학연구
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• 제28권2호
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• pp.147-161
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• 2001

Efficiency and competitive power in agribusiness management has became important issue due to the rapid changes in farming environment under new WTO agreement. To increase competitive power, small-sized petty farm should be restructured to be specialized large-scaled farming system. Trust farming corporation(TFC) has been introduced to increase farm productivity and competitive power through large scale farming system and refined management skills. Eventually, TFCs are expected to revitalize rural economy. TFCs are increasing in numbers, but they are unsatisfactory in quality often with insolvent operations. The typical problems with TFCs are internal conflicts among members, lack of management abilities and incentives, inefficiency in machinery use, and insolvent operations. The self effort by members and legal-institutional assistance can alleviate the negative factors against the rational for cooperative management and sustain TFCs. This study identifies the management problems of TFCs. To provide the methods for increasing management efficiency, improving rational management skills, and hence to help revitalizing the rural economy with competitive power, 20 TFCs in Nonsan County is surveyed. The major findings are as follows; 1) According to the survey result of 20 trust farming corporations, investments on the accumulation of knowledges and information, accounting management, machinery management are required due to the present lack of management/accounting ability. There also exist problems associated with revenue sources, labor uses, and public recognition. To increase management efficiency under current situation, corporations should import active business plans with expanding farming execution and off-farm season business. 2) Based on the result of corporations' business analysis, more than 50% of the corporations were not able to provide profit dividends to the members. It suggests that trust farming corporations need appropriate and stable revenue sources to sustain business. It is also required that corporations should reduce their excessive expenditure on fixed assets. 3) Theoretical amounts of consignment fees for tillage operation, planting, and harvesting were found to be 338,874 won, 216,596 won, and 332,318 won, respectively. Although actual levels of fee are 110%~120% of these theoretical levels of consignment fee, corporations' expected fee levels could not be acheived because of competency of consignment market.

• 대한안전경영과학회지
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• 제16권2호
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• pp.231-236
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• 2014

In this study, the changes in collection efficiencies due to the time changes of activated carbons were ascertained, and in order to identify the magnitude of adsorption, the before-use and after-use iodine adsorption values were analyzed. In addition, as a result of examining the characteristics of continuous process and non-continuous process and as a result of investigating whether the emission standards would be maintained, the continuous process and printing facilities were seen as not being able to maintain the emission standards. Also were found, in the case of non-continuous process,-taking into consideration the special nature of the job -for 4${\o}$ palletized charcoal, a collection efficiency near 50% was shown even after 96 hours. Also, when the inlet concentration was about 300ppm, it is thought that the emission standards would be maintained if the activated carbons are replaced within at least 96 hours in the case of 4${\o}$ palletized charcoal and the use was deemed pointless in the case of carbon. The results of this study are expected to provide assistance in selecting replacement periods for activated carbons and in selecting absorbents at the project sites, and are expected to be of significant help in the selection of precipitators that can collect total hydrocarbons for compliance of the emission standards.

• 한국폐기물자원순환학회지
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• 제35권8호
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• pp.762-769
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• 2018

This study was carried out to examine the improvement plan by analyzing the characteristics of imported wastes, operation rate, and benefits of energy recovery for incineration facilities with a treatment capacity greater than 50 ton/day. The incineration facility capacity increased by 3,280 tons over 15 years, and the actual incineration rate increased to 2,783 ton/day. The operation rate dropped to 76% in 2010 and then rose again to 81% in 2016. The actual calorific value compared to the design calorific value increased by 33.8% from 94.6% in 2002 to 128.4% in 2016. The recovery efficiency decreased by 29% over 16 years from 110.7% to 81.7% in 2002. Recovery and sales of thermal energy from the incinerator (capacity 200 ton/day) dominated the operation cost, and operating income was generated by energy sales (such as power generation and steam). The treatment capacity increased by 11% to 18% after the recalculation of the incineration capacity and has remained consistently above 90% in most facilities to date. In order to solve the problem of high calorific value waste, wastewater, leachate, and clean water should be mixed and incinerated, and heat recovery should be performed through a water-cooled grate and water cooling wall installation. Twenty-five of the 38 incineration facilities (about 70%) are due for a major repair. After the main repair of the facility, the operation rate is expected to increase and the operating cost is expected to decline due to energy recovery. Inspection and repair should be carried out in a timely manner to increase incineration and heat energy recovery efficiencies.

• 한국콘텐츠학회논문지
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• 제20권12호
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• pp.136-144
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• 2020

선행연구에서는 노동투자비효율성이 정보비대칭이 심하고, 경영자와 외부 투자자들간의 대리인 문제가 클수록 발생한다고 보고하였다. 따라서 노동투자의 비효율성이 높은 기업의 경우 경영자가 기업가치를 훼손시킬 수 있는 기회주의적 의사결정을 내릴 가능성이 높아진다. 이에 본 연구는 시장에서 투자자들이 비효율적으로 노동투자 의사결정이 이루어지는 기업들의 회계정보를 투자의사결정에 유용하게 사용할 가능성이 낮아짐에 따라 노동투자 비효율성이 높아질수록 회계정보의 가치관련성이 감소하는지 살펴보고자 한다. 노동투자효율성은 기업의 실제 노동투자수준과 예상되는 적정노동투자수준의 차이로 측정하여 이 차이가 커질수록 노동투자가 비효율적으로 이루어지는 것으로 판단하였다. 2002년부터 2018년까지 한국거래소에 상장된 기업의 데이터를 사용하여 분석한 결과, 노동투자에 대한 비효율성이 증가할수록 회계이익의 가치관련성이 감소하는 것으로 나타났다. 본 연구는 기업의 경쟁력에 중요한 요인으로 작용하는 인력에 대한 투자가 비효율적으로 이루어지는 기업일수록 회계이익에 대한 정보 유용성이 감소한다는 실증적인 근거를 제시하였다는 측면에서 공헌점을 찾을 수 있다.

• 한국인터넷방송통신학회논문지
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• 제23권6호
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• pp.145-155
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• 2023

도파관과 매칭구조를 이용하여 X-band에서 고효율 결합특성을 갖는 방사형 결합기를 설계 및 제작하였다. 특히 소형으로 제작하기 위해서 도파관 하나에 포트를 2개 매칭할 수 있는 이중 도파관-동축 변환 구조를 적용하였다. 이러한 구조를 적용하면 일반적인 동축-도파관 방사형 결합기보다 소형 제작이 가능해진다. X-band 대역인 9.2-10GHz 에서 측정결과 반사손실 -18.408dB 이하, 출력삽입손실 0.206dB 이하의 결과값을 얻었고 또한 출력결합효율은 95.37% 이상의 높은 값을 얻을 수 있었다. 향후 밀리미터파 대역에서 고출력 송신기용 결합부에 활용 가능할 것으로 기대된다. 특히 크기와 무게를 줄임으로서 활용범위가 더 늘어날 것으로 기대된다.

• 스마트미디어저널
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• 제13권1호
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• pp.18-23
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• 2024

스마트팜의 전력 효율 관리는 기후 변화와의 연계로 중요성을 가지고 있다. 기후 변화가 농업에 부정적인 영향을 미치는 가운데, 미래의 농업은 스마트팜을 활용하여 기후 영향을 최소화할 것으로 예상되고 있으나 스마트팜의 전력 소비는 현재의 전기 생산 체제로 인해 기후 위기를 악화시킬 우려가 있다. 이에 따라 스마트팜의 전력 사용을 효율적으로 관리하고 최적화하는 것이 필수적이다. 본 연구에서는 스마트팜 장비의 전력 사용량을 실시간으로 모니터링하고, GRU를 활용하여 1시간 뒤의 전력 사용량을 예측하는 시스템을 제안한다. CT 센서를 설치하여 전력량을 수집하고, 이를 분석하여 이상 패턴을 탐지하고 예방한다. 또한 IoT 기술과 결합하여 전체 전력 사용량을 효율적으로 관리하고 모니터링한다. 이를 통해 전력 사용을 최적화하고, 에너지 효율성을 향상시켜 탄소 배출을 줄일 수 있다. 이 시스템은 스마트팜의 에너지 관리뿐아니라 전반적인 에너지 사용 효율성을 향상시킬 것으로 기대된다.

• 한국레이저가공학회:학술대회논문집
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• 한국레이저가공학회 1998년도 추계학술발표대회 초록개요집
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• pp.0-0
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• 1998

-Part I- As market needs become more various, the production of smaller quantities of a wider variety of products becomes increasingly important. In addition, in order to meet demands for more efficient production, long-term unmanned factory operation is prevailing at a remarkable pace. Within this context, laser machines are gaining increasing popularity for use in applications such as cutting and welding metallic and ceramic materials. FANUC supplies four models of $CO_2$ laser oscillators with laser power ranging from 1.5㎾ to 6㎾ on an OEM basis to machine tool builders. However, FANUC has been requested to produce laser oscillators that allow more compact and lower-cost laser machines to be built. To meet such demands, FANUC has developed six models of Slab type YAG laser oscillators with output power ranging from 150W to 2㎾. These oscillators are designed mainly fur cutting and welding sheet metals. The oscillator has an exceptionally superior laser beam quality compared to conventional YAG laser oscillators, thus providing significantly improved machining capability. In addition, the laser beam of the oscillator can be efficiently transmitted through quartz optical fibers, enabling laser machines to be simplified and made more compact. This paper introduces the features of FANUC’s developed Slab type YAG laser oscillators and their applications. - Part II - All-solid-state lasers employing laser diodes (LD) as a source of pumping solid-state laser feature high efficiency, compactness, and high reliability. Thus, they are expected to provide a new generation of processing tools in various fields, especially in automobile and aircraft industries where great hopes are being placed on laser welding technology for steel plates and aluminum materials for which a significant growth in demand is expected. Also, in power plants, it is hoped that reliability and safety will be improved by using the laser welding technology. As in the above, the advent of high-power all-solid-state lasers may not only bring a great technological innovation to existing industry, but also create new industry. This is the background for this project, which has set its sights on the development of high-power, all-solid-state lasers with an average output of over 10㎾, an oscillation efficiency of over 20%, and a laser head volume of below 0.05㎥. FANUC Ltd. is responsible for the research and development of slab type lasers, and TOSHIBA Corp. far rod type lasers. By pumping slab type Nd: YAG crystal and by using quasi-continuous wave (QCW) type LD stacks, FANUC has already obtained an average output power of 1.7㎾, an optical conversion efficiency of 42%, and an electro-optical conversion efficiency of 16%. These conversion efficiencies are the best results the world has ever seen in the field of high-power all-solid-state lasers. TOSHIBA Corp. has also obtained an output power of 1.2㎾, an optical conversion efficiency of 30％, and an electro-optical conversion efficiency of 12%, by pumping the rod type Nd: YAG crystal by continuous wave (CW) type LD stacks. The laser power achieved by TOSHIBA Corp. is also a new world record in the field of rod type all-solid-state lasers. This report provides details of the above results and some information on future development plans.