수경재배 시스템에서 이온선택성전극(ISE)를 이용하여 배액 내 칼륨, 칼슘, 질소 이온농도를 측정하고 배양액 조제알고리즘을 통해 부족농도를 보충하는 시스템을 개발하였다. 또한, ISE로 실시간 측정이 어려운 다량원소 중 미측정 이온에 대한 농도는 배액 내 다량원소 간 상관관계를 통해 예측하였다. 회수된 배액을 재사용하기 위해서는 배액의 이온농도 측정도 중요하지만 부족한 양을 어떻게 정확하게 공급해 줄 것인지도 중요하다. 부족 농도를 보충하기 위해 비료농축액을 사용하였으며, 회수된 배액 내 미측정된 다량원소 이온들의 농도를 예측하기 위해 상추 재배실험 을 통해 이온 크로마토그래피로 측정한 다량원소 간 관계를 분석하였다. PO4의 경우 전극을 이용하여 측정 가능한 다량원소 간의 상관관계는 결정계수 K=0.91, NO3=0.96, Ca=0.87로 모두 높은 관계를 나타내었다. 이 중 결정계수가 가장 높은 질산을 조제 알고리즘에 사용하였다. Mg의 경우 K=0.93, NO3=0.93, Ca=0.99로 셋 중 Ca와 가장 밀접한 관계를 보여 Ca를 조제 알고리즘에 사용하였다. SO4의 경우 K=0.86, NO3=0.97, Ca=0.95를 나타냈으며 결정계수가 가장 높은 NO3를 알고리즘에 적용하여 양액을 조제 하려고 했으나 해당 비료의 과잉공급이 발생하게 되어 Ca을 적용하여 양액을 조제 하였다. 알고리즘을 이용하여 조제한 결과 전체적으로 10% 내의 오차로 나타났지만 비료농축액 공급량 결정 시 투입되는 비료를 순차적으로 결정할 뿐만 아니라 특정 이온의 과잉 또는 부족 농도가 최소화될 수 있는 방향으로 알고리즘을 만들었기 때문에 NO3과 SO4에 대한 공급오차는 발생할 수밖에 없었다. 개발된 시스템의 성능을 평가하고자 재배실험에서 나온 배액과 제조된 양액을 비교하였고 K, Ca, NO3의 공급오차는 평균 ±10%내를 보여 예상치보다 다소 많은 오차를 보였지만 회수된 배액을 재조제하여 공급하였을 때 실제 작물재배에서 목표 농도를 유지할 수 있을 것으로 보였다. 하지만 보다 정밀한 제어를 위해 상추 생육단계별 이온흡수량 데이터베이스를 구축하여 조제알고리즘에 적용시켜 배양액을 공급할 수 있는 연구가 필요하다고 판단되었다.

In this study, the heat transfer characteristics of pilot wave heat exchanger for white smoke reduction system was investigated. The performance of the wave and honeycomb heat exchanger combined with the first stage, second stage and third stage was tested using a calorimeter. Air and water inlet/outlet temperature and flow rate, pressure drop and dehumidification amount were measured to compare the heat transfer performance according to the type and the combination of heat exchanger. The heat transfer rate and dehumidification amount of the wave heat exchanger were higher than that of the honeycomb heat exchanger, and the pressure drop was low. As the stage increased, the heat transfer rate and the increase of the dehumidification amount were more pronounced, and the pressure drop linearly increased. The wave heat exchanger had a lower flow resistance than the honeycomb heat exchanger with the honeycomb structure and had a higher heat transfer effect due to the convection, so the water outlet temperature was higher in the wave heat exchanger.

The paper investigates the Brain Drain in Chinese family business based on a sample of 319 family businesses in China. Using a fuzzy set qualitative comparative analysis (fsQCA) to uncover different combinations of conditions (pay and welfare, work environment, management style of the leaders, and career planning) that are sufficient to achieve high and low brain drain. The results show that pay and welfare is a necessary but not a sufficient condition by itself to achieve high brain drain. The findings show that three causal recipes are equifinal in achieving high brain drain. The first causal recipe combines high work environment with low level of career planning and with high pay and welfare. The second combines low work environment with high level of career planning and with high pay and welfare. Finally, the third combines high work environment with high level of management style of the leaders and with high pay and welfare. The study also found two causal configurations that are equifinal to achieve low brain drain. Moreover, these combinations are not a mirror of the combinations founded for high brain drain. This study offers several implications to both researchers and business practitioners: It is acquired that in order to prevent brain drain, the pay and welfare of employees should be raised while the management philosophy should pay attention to humans in the first place. Secondly, the leaders need to improve their own quality so as to strengthen the management of family businesses. Finally, a refined human resource system needs to be established. After brain drain, enterprises should perfect their contract constraining mechanism and, bring in suitable talents promptly so that the loss is minimised.

As the hydrofluoric acid leak at Gumi-si, Gyeongsangbuk-do or hydrochloric acid leak at Ulsan demonstrated that chemical related accidents were mostly caused by large amounts of volatile toxic substances leaked due to the damages of storage tank. The purpose of this study was to develop PFA lined bottom drain ball valve for using in semiconductor, LCD manufacturing fields, pharmaceutical and others. For this purpose, modeling and design of PFA lined bottom drain ball valve, casting mold and casting production, design and manufacturing of lining mold, design and manufacturing of lining jig, PFA forming and assembly have been carried out for 50A×25A PFA lined bottom drain ball valve. In addition, a performance test was performed for the pin hole, density, tensile strength, elongation and elastic modulus of the developed prototype. As a result, the performance of the prototype valve satisfies all the objects of this study. Also, the developed valve was a very good performance compared with conventional 50A×25A imported valve with the same size.

A series of injection and drainage test were conducted on an circular acrylic tube to investigate the pressure generated by the accumulated fill materials inside a circular acrylic tube structure. The acrylic tube was filled by means of gravity filling with a slurry material having an average water content of 700%. The water head during the filling process was 1.8m and the bottom pressure during initial filling was 20.18kPa. The recorded stress at the sides of the acrylic tube was 17.89kPa during the filling process and was reduced to 13.58kPa during the leaving process. Continuous drainage of the acrylic tube has greatly influenced the stresses around the tube structure. As the water is gradually allowed to overflow, the generated pressure at the topmost pressure sensor of the tube was reduced further to 2.17kPa. Eventually, the initially liquid state slurry material transforms into plastic state after water has dissipated and substantial soil particles are deposited in the acrylic tube. The final water content of the deposited silt inside the acrylic tube after the test was 42%. It was found that the state of stresses(geo-static earth pressures) in the acrylic tube was anisotropic rather than isotropic.

This study is for reduction of heat island to control the rise in climate, temperature changes, according to the passage of a vehicle due to cyclic loading, such as cracks in the asphalt layer in order to determine the proper diameter control and caused the asphalt to prevent damage. Slab drain is suitable to determine drainage asphalt diameter.

산업기술의 부정한 유출을 방지하고 이를 보호하여 국내산업의 경쟁력을 강화하고 국가의 안전보장과 국민경제의 발전에 기여하고자 2007년 제정된 ｢산업기술의 유출방지 및 보호에 관한 법률｣의 개정안이 최근 국회에 제출되었다. 개정안에서는 산업기술의 정의와 국가핵심기술의 대상범위에 대한 모호성을 제거하고, 산업기술 침해행위에 대한 금지청구권을 신설하여 법 집행의 실효성을 제고하고자 하였다. 또한 산업기술보호위원회의 운영체계를 조정하여 실질에 맞게 정비하고자 하였다. 특히 이번 개정안은 외국인투자에 의한 국가핵심기술의 유출을 통제할 수 있는 최소한의 법적 근거를 마련하였다는 점에 큰 의미가 있다. 과거 수차례의 입법적 시도를 무산시켰던 투자위축에 대한 우려를 고려하여 동 개정안에서는 자율적 신고제를 원칙으로 하고, 그 대상을 국가로부터 개발지원을 받은 기술로 한정하였으며, 또한 산업기술보호위원회의 심의를 거치도록 하여 국가안보와 투자촉진이라는 상반된 이해관계를 적절히 조정하고 있다.이 글에서는 최근 국회 법사위에서 대안으로 의결된 개정시안을 중심으로 위에서 언급한 주요내용을 분석하고 있다. 또한 이 글은 동 개정안에서 미처 다루지 못했던 향후과제로서 처벌조항의 개선, 산업보안관리사제도 및 산업보안관리체계 인증제도의 도입, 그리고 국가핵심기술 사전판정제도의 도입에 관해 구체적인 제안하고 있다. 즉, 처벌조항과 관련해서는 현행법 제14조에서 위반행위에 대해 일괄적으로 법정형을 정하고 있는 문제점을 지적하고 입법체계상 경미한 침해행위부터 중대한 침해행위까지 행위유형별로 세분화된 법정형을 규정할 것을 제시하였다. 그리고 국회 논의과정에서 제외되었던 산업보안관리사 및 산업보안관리체계 인증제도의 경우 시장에서 이들 제도에 대한 수요가 여전히 존재하고 있으므로 추가적인 연구를 통해 보다 차별성 있는 제도로 거듭 발전시킬 것으로 제안하고 있으며, 끝으로 현행법은 국가핵심기술 자체를 지정할 뿐 이를 보유하고 있는 기관을 지정하지 않는다는 문제점을 고려하여 수범자가 스스로 국가핵심기술 보유기관에 해당하는지를 알 수 있도록 사전판정제도의 도입을 제안하고 있다.

In science and engineering programs in the U.S. in 2000 China, South Korea and India were top countries of origin sending students. More than half of the students intend to stay in the U.S. Immigration, education and occupational choices all have human ca

Korea's protected horticulture is rapidly increasing in scale due to various advantages such as year-round harvesting, labor savings through automation and shortened culture period, and greater income generation. This study was conducted to investigate the impact of protected horticulture on water quality. The results of this study are expected to provide basic data contributing to improvements towards sustainable agriculture and eco-friendly design of protected horticulture complex. The average T-N and T-P loads from vinyl greenhouses were 286.55± 143.98 mg/L and 59.14±13.77 mg/L, respectively and those from glass greenhouses 380.68 ± 150.41 mg/L and 61.85±20.72 mg/L. The annual discharge of wastewater derived from the monthly discharge from the horticulture greenhouses were estimated at 2597 ton/ha, with the annual phosphorus load amounting to 155.3 kg/ha. The average T-N and T-P loads in the tested greenhouse effluents were in excess of 8.3- and 13.5-fold the standards for the Korean wastewater plant effluent. The waste nutrient solution discharged from a protected horticulture complex can cause water contamination. Therefore, there is a need to conduct follow-up research using a water purification system or a trench method to develop a eco-friendly protected horticulture complex for sustainable agriculture.

NATM터널의 경우 대부분 산악지역에 위치함에 따라 배수형 터널이 지배적이다. 그러나 NATM 터널에서의 배수기능 저하와 수압작용, 이에 따른 라이닝 변상(누수, 백태 등)이 다수 보고되었으며, 매년 내구성과 사용성 확보를 위한 유지관리 비용이 투입되고 있다. 본 연구에서는 고속철도 NATM 터널을 대상으로 최근 실시한 정밀안전진단 결과를 활용하여 횡배수관 막힘 현상과 지보패턴과의 상관관계 분석사례를 소개하고 향후 개선방안에 대한 연구방향을 제시하고자 한다.

This study sought to find a new diagnostic method. The drain hole temperature and the upstream water temperature change were measured for 1 year. The purpose of this study was to analyze the correlation between the temperature of the drain hole and the upstream temperature.

In this study, in order to survey the concrete dam leakage use the Thermal Line Sensor (TLS) temperature monitoring instruments. The temperature monitoring locations are two drain hole of concrete dam and the upsteam water temperature of dam.

This study is for the damage with lack of drain pipe length and it is presented for the improved references which is ｢Design and management guidelines of road drainage facilities｣.

Various methods were investigated to confirm the clogging of the drain hole of the concrete dam and recover it. The effects of drainage holes were investigated through re-drilling at the two locations.

This study is for the damage with lack of drain pipe length and it is presented for the improved references which is ｢Design and management guidelines of road drainage facilities｣.