• Journal of Wetlands Research
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• v.13 no.1
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• pp.139-148
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• 2011

Web structure of spiders is a foraging strategy as well as an investment to get prey. In order to make a good foraging decision spiders should change its foraging strategy in the basis of sensory information provided by potential prey species. We conducted experiments to demonstrate whether a wasp spider, Argiope bruennichi modifies its web-building behavior after experiencing sensory information emitted by a cricket species, Teleogryllus emma. To know how the web structures would be modified, we quantified web characteristics after providing sensory information of the cricket and compared to the control group. Web construction decreased in the course of the experiment in both, control group(without stimulus) and experimental group(with stimuli). The results did not show remarkable differences between two groups. However, on the first day after providing sensory information of the cricket, the web-building behavior of A. bruennichi decreased only in 3.7% of the experimental group individuals against 11.8% of the control group individuals. The number of the stabilimentum constructions decreased overall in both groups. On the first day the decreasing proportion was doubled in the control group(14.7%), comparing to the experimental group(7.4%). The individuals did not lower its web height and did not extend its web area according to sensory information of the prey.

• Journal of the Korea Institute of Building Construction
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• v.9 no.6
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• pp.183-188
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• 2009

HwaSeong (Suwon Fortress) was built during the reign of King Jeong-jo in the Choseon Dynasty. Detailed information on the construction of HwaSeong can be found in Hwaseong Seongyeok Euigui. In this sense, it is necessary to perform a comparative analysis on the Hwaseong Seongyeok Euigui based on construction management factors. This paper aims to analyze the HwaSeong construction project from a modern construction perspective by comparing and reviewing information related to the procurement of construction materials of the time. For this, wooden and steel materials and tiles were analyzed by supply area, supply channel, type and price. From the results of the analysis, it is found that the government used both private and official channels to supply materials. In particular, except for wooden materials that could be supplied from Bongsan, the supply of materials showed a high dependency on private channels. In terms of steel, it was almost 30 percent cheaper through private channels than when purchased through the official channel. Finally, materials vulnerable to damage like tiles were manufactured from the areas near the construction site. From this fact it can be interpreted that the government had a flexible procurement system, including manufacturing on the spot and external suppliers,depending on the property of the material. It is expected these analytical results will serve as key data to understand the management factors in constructing HwaSeong.

• Journal of the Korean Association of Geographic Information Studies
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• v.24 no.4
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• pp.194-208
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• 2021

The Hwanggang Dam in North Korea is located upstream of the Imjin River which is a shared river in the border area. It is known to have a reservoir capacity of 350 million cubic meters and releases a discharge primarily for generating hydroelectric power and partly for transferring to the Yesung River basin. Due to the supply of water from the Hwanggang Dam to another basin, the flow of the Imjin River has decreased, which has a negative impact on the water supply, river maintenance flow, water quality, and ecological environment in Korea. However, due to the special national security issue of the South and North Korea border region, the hydrological data is not shared, and the operation method of the Hwanggang Dam is unknown, so there is a risk of damage to the southern part of the downstream area. In this study, the monthly diversion as the long-term runoff concept was derived through the calibrated hydrological model based on optical remotely sensed Images and water balance analysis. As a result of the water balance analysis from January 2019 to September 2021, the average diversion of the Hwanggang Dam was 29.2m³/s, which is equivalent to 922 million tons per year and 45.6% of the annual inflow of 2.02 million tons into the Hwanggang Dam.

• Economic and Environmental Geology
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• v.55 no.4
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• pp.399-406
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• 2022

In line with the megatrend of 2050 carbon neutrality, the amount of critical minerals used in clean-energy technology is expected to increase fourfold and sixfold, respectively, according to the Paris Agreement-based scenario as well as the 2050 carbon-neutrality scenario. And, in the case of Korea, in terms of the battery supply chain used for secondary batteries, the midstream that manufactures battery materials and battery cell packs shows strength, but the upstream that provides and processes raw materials is experiencing difficulties. The Korea Institute of Geoscience and Mineral Resources has established a strategy to secure lithium, nickel, and cobalt and is conducting surveys to respond to the upstream risk of these types of battery raw materials. In the case of lithium, exploration has been carried out in Uljin, Gyeongsangbuk-do since 2020, and by the end of 2021, the survey area was selected for precision exploration by synthesizing all exploration data and building a 3D model. Potential resources will be assessed in 2022. In the case of nickel, the prospective site will be selected by the end of 2022 through a preliminary survey targeting 10 nickel sulfide deposits that have been prospected in the past. In the case of cobalt, Boguk cobalt is known only in South Korea, but there is only a record that cobalt was produced as a minor constituent of hydrothermal deposit. According to the literature, a cobalt ore body was found in the contact area between serpentinite and granite, and a protocol for cobalt exploration in Korea will be established.

• Journal of the Korea society of information convergence
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• v.5 no.2
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• pp.49-58
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• 2012

Korea has entered into an aging society at an exceptionally high speed. Increasing aged workers give pressure on Korean companies with seniority based pay system with labor costs. The wage peak system has been introduced to Korean companies as an alternative to early retirements. The wage peak system currently adopted in Korea is mainly the aging-limit-security model. But in the future we should actively adopt the employment-extension model. To operate wage peak system successfully, I suggest introduction of the individual wage peak system, development of suitable jobs for the aged, selective application by job classification, incentive graded by performance evaluation, and working hour reduction with the decreased rate of wage.

• Journal of the korean veterinary medical association
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• v.37 no.1
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• pp.52-57
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• 2001

전통적 유방염치료에서 변화는 현대적 우유생산 설비인 덴마크의 연구로부터 나온 결과와 문헌적 고찰을 배경으로 논의된 것이다. 덴마크의 전통적 농장운영제도는 전통적 농부들의 현대화와 1987년에 변화 시킨 정부의 규제법규로 제도화된 것에 의하여 근본적인 형태의 목표로 특성화되어 진다. 모든 질병은 품종, 우사 설비, 사료공급과 경영작전을 통하여 예방되어지는 전통적 농장운영체제에 대한 지침에 의존되어야 하였다. 치료의 농가 선택에 대하여 특별히 관심을 둔 정부규칙은 1. 모든 의학적 예방은 금지된다. 2. 의학적 치료에 뒤 따르는 배출시간은 전통적 농장운영에 비하여 3배가 연장된다. 3. 모든 치료는 수의사에 의하여 수행되어야 한다. 연구는 예방과 치료작전에 초점을 맞춘 전통적 농장운영체제에서 수행한 것이다. 이 과제에서 몇 가지 유방염은 농가자신의 치료로 설명되었으며 그 내용은 다음과 같다. 각 목장에서 유방염은 마싸지 시행과 캠퍼(camphor)또는 페퍼민트오일(pebbermint oil)의 국소응용 그리고 어떤 목장은 동종 요법적 치료(同種 療法的 治療 = Homoeopathic treatment)로 손착유로 하고 농가자신이 치료하였다. 이 결과에서 농부자신의 치료와 수의사 치료가 보여 준 것은 성공 사이에 유의한 차이가 없다. 변화와 전통적 치료에 추가하여 비의학적 치료가 검토되었다. 유방염 건에서 농부 대 수의사 역할은 유방염 문제점이 있는 목장에 근거하면은 똑같다고 검토되었다. 동종 요법적 치료의 문헌연구는 경험을 통하여 수행되어진 것이다. 현 과제는 목장의 치료작전 안에서 종합되고 있는 동종 요법적 치료의 실제적 현상이 설명되고 있다 동종요법은 어떤 건에서 반응이 제안될 수 있는 유방염치료와 관계되는 치료 방법이다. 그러나 덴마크의 경험에서 전통은 유방염 건에서 치료의 선택에 영향이 있을 것이라는 것으로 비교적 제한되어 있다 이 치료에 대한 원리의 배경을 검토하였다.

• Journal of ILASS-Korea
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• v.1 no.1
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• pp.63-75
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• 1996

The purpose of this study is to investigate the break-up characteristics by taking advantage of a two-phase coaxial nozzle. Air and water are utilized as working fluids and the mass ratio air/water has been controlled to characterize the atomization, diffusion and development of mixing process. By way of a photographic technique, conventional developing structures and diffusion angles have been analyzed systematically with variations of mass ratios. The turbulent flow components of the atomized particles were measured by a two channel LDV system and the data were treated by an on-lined measurement equipment. According to the photographic results the spreading angles decreased because the axial inertia moment was relatively higher than the lateral one with respect to the increase of mass ratio. It is found the jet flow diffuses linearly in a certain limit region while the atomizing characteristics, in terms of the distributions of particle diameters did not show particular differences. It may be expected that these fundamental results can be used as reference data in studying the atomization, breakup and diffusions.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1991.04a
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• pp.47-52
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• 1991

주거환경을 침해하는 소음의 주된 요인은 가전제품으로서, 대부분의 가전제 품은 전기모터에 의해 구동된다. 가전제품을 작동시키는 전기모터는 가전제 품에 기진력을 주는 한편 공기중으로 소음을 방사함으로서 조용한 주거환경 을 해치게 된다. 따라서 조용하고 쾌적한 주거환경 확보를 위해서는 가전제 품용 구동모터의 소음을 효과적으로 차단 또는 감소해야 한다. 모터의 소음 원은 그 모터의 종류와 형태에 따라 약간씩은 다를 수 있으나 일반적으로 크게 기계적 소음, 공기 역학적 소음, 전자기 소음, 열/전기 화학적 소음 등 으로 분류된다. 이들 중 모터의 소음에 큰 영향을 주는 것은 기계적 소음, 공기 역학적 소음, 전자기 소음이며 열/전기 화학적 소음은 매우 작은 편이 다. 또한 공기 역학적 소음은 모터에 팬이 부착될 경우에만 큰 문제가 될 뿐 이며, 팬이 부착되지 않을 경우에는 기계적 소음과 전자기 소음이 주된 소음 원이 된다. 기계적 소음과 전자기 소음은 어느 것이 주된 소음원인지는 일반 적으로 잘 알 수 없기 때문에, 개별적인 연구와 실험을 통하여 파악해야 한 다. 기계적 소음은 주로 회전자의 불균형 회전에 의한 진동 및 그로 인한 외 부 프레임의 진동으로 대별되며, 전자기 소음은 주로 공급(Air-Gap)에서의 투과파(permeance wave)와 기자력(magneto-motive force)에 의한 반지름 방향의 힘에 의해 주로 발생된다. 본 연구에서는 기계적 소음과 전자기 소음 중 모터 소음에 영향이 큰 소음원을 판별해 내고 모델 실험을 통하여 감소 방안을 검토하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.282-286
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• 2009

1979년 준공된 수도권 광역상수도 1단계 시설은 상당한 노후화가 진행되었을 것으로 예상되며, 또한 향후 한강하류권 용수공급계획이 예정되어 있어 내부부식 및 관로손상부 개량의 시급성이 제기되었다. 이에 따라 직경 2,800${\sim}$800mm의 초대구경 도수관 53.9km의 개량을 위한 사업이 추진되었으며 시공성, 환경성, 경제성 등의 여러 항목에 대한 검토 결과 신개념 녹색공법인 비굴착식 건식일체형 공법이 최종 선정되었다. 그동안 기존관 개량공사에서 주로 사용되었던 굴착공법이 굴착에 따른 공기지연, 소음 분진 악취 등의 환경오염, 전구간 굴착에 따른 공사비 증가 등 많은 문제점을 안고 있는 것에 반해, 동사업에서 채택된 비굴착공법은 관로내에서 작업이 이루어지므로 공기단축, 환경오염 최소화에 따른 민원발생 최소화, 작업구만 굴착함에서 오는 공사비 절감 등 상대적으로 훨씬 우수한 것으로 평가된다. 동공법에 따르면 관내부 갱생공사는 '배수 및 잔류토사 제거'${\to}$'관내건조'${\to}$'표면처리'${\to}$'프라이머도장'${\to}$'본도장'의 순으로 진행된다. 일체형 장비에 의한 이와 같은 초대형관의 자동화시공은 세계에서 처음 적용되는 것이다.

• Journal of Korean Institute of Industrial Engineers
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• v.41 no.4
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• pp.344-351
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• 2015

Recently, an ERP (Enterprise resource Planning) system has been becoming an essential S/W tool for companies to manage their business processes and manufacturing resources. As the information exchange becomes more complex, not only corporate companies but also small- and mid- sized enterprises (SMEs) are required to build an ERP system. However, for small- and middle- sized companies, the adoption of ERP systems becomes challenging due to high cost and long installation time of the system. This paper presents a novel concept of an adaptive ERP system incorporating the ontology structure of the business supply chain information. The proposed ERP installation methodology is illustrated with an example of a door-trim manufacturing company in the automotive supply chain.