• 디지털산업정보학회논문지
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• 제16권4호
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• pp.29-42
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• 2020

SCADA (Supervisory Control and Data Acquisition) systems for remote monitoring, data acquisition and control are applied to major industrial infrastructures including power, water and railroad. Recently, there are many researches on key management scheme for secure communication due to change to the open network environment. These systems are located at far distances and are connected to the main control center through various types of communication methods. Due to the nature of these systems, they are becoming the significant targets of cyber attack. We propose an efficient key management scheme which is established on ID-based cryptosystem without an expensive computation on MTU (Master Terminal Unit), Sub-MTU, and RTU (Remote Terminal Unit). The proposed method is secure and effective in key management among multiple legitimate devices.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.281-285
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• 2001

This study was carried out to improve the performance of heat recovery device attached to exhaust gas flue connected to combustion chamber of greenhouse heating system. Three different units were prepared for the comparison of heat recovery performance; AB-type(control unit) is exactly the same with the typical one fabricated for previous study of analyzing heat recovery performance in greenhouse heating system, other two types(C-type and D-type) modified from the control unit are different in the aspects of airflow direction(U-turn airflow) and pipe arrangement. The results are summarized as follows; 1. In the case of Type-AB, when considering the initial cost and current electricity fee required for system operation, it is expected that one or two years at most would be enough to return the whole cost invested. 2. Type-C and Type-D, basically different with Type-AB in the aspect of airflow pattern, are not sensitive to the change of blower capacity with higher than $25\;m^{3}/min$. Therefore, heat recovery performance was not improved so significantly with the increment of blower capacity. This is assumed to be that air flow resistance in high air capacity reduces the heat exchange rate as well. Never the less, compared with control unit, resultant heat recovery rate in Type-C and Type-D were improved by about 5% and 13%, respectively. 3. Desirable blower capacity for these heat recovery units experimented are expected to be about $25\;m^{3}/min$, and at the proper blower capacity, U-turn airflow units showed better heat recovery performance than control unit. But, without regard to the type of heat recovery unit, it is recommended that comprehensive consideration of system's physical factors such as pipe arrangement density, unit pipe length and pipe thickness, etc., are required for the optimization of heat recovery system in the aspects of not only energy conservation but economic system design.

• 한국초전도ㆍ저온공학회논문지
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• 제5권1호
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• pp.133-135
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• 2003

Cryogenic systems are requirement for the operation of HTS power cables. In general, HTS power cables require temperature below 77K, a temperature that can be achieved from the liquid nitrogen at latm or sub-cooled LN2 above latm. HTS power cable needs sufficient refrigeration to overcome its low temperature heat loading. This loading typically cones in two forms : (1) heat leaks from the surroundings and (2) internal heat generation. This paper explains the cooling test system of 10m HTS power cable. This system is composed of storage dewar, auto fill system, core cryostat and cold-box. Storage dewar is a LN2 storage tank and auto fill system is a LN2 supply device to the sub-cooler, Core cryostat is a LN2 flow line. Cold box is a control unit of temperature and flow rate. It is composed of control valve, flow meter, sub-cooler and circulation pump, etc..

• 한국기계가공학회지
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• 제13권6호
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• pp.15-22
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• 2014

With a conventional positioning apparatus, it is very difficult simultaneously to achieve desired driving ranges and precision levels at the sub-micrometer level. Generally, a lead screw and friction drive have been used as servo control systems. These have large driving ranges, and high-speed positioning is feasible. In this study, we present a global servo system controlled by a laser interferometer acting as a displacement measurement sensor for achieving positioning accuracy at the sub-micrometer level.

• 한국습지학회지
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• 제24권4호
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• pp.345-353
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• 2022

산업과 생활환경에서 사용된 공학적 미세입자는 결국 하수처리장을 거쳐 수계로 배출되므로 미세입자의 수계 배출 제어에 매우 중요한 역할을 담당하고 있다. 그러나 다수 연구에서 하수처리장 유출수 내 미세입자의 농도가 무영향관찰농도(No Observed Effective Concentration, NOEC)를 빈번히 초과하고 있는 것으로 보고되고 있어 전통적인 하수처리 기능과 더불어 미세입자를 보다 효과적으로 제어할 수 있도록 하수처리장의 설계와 운영을 최적화시킬 필요가 있다. 이를 위해서는 하수처리장 내 단위공정별 특성 및 운전조건에 따른 미세입자의 거동특성과 제거효율에 대한 예측이 선행되어야 한다. 이에 본 연구에서는 하수처리장 내 각 공정 특성별 및 주요 운전조건의 영향에 따른 미세입자 제거효율예측을 위한 모델을 개발함으로써 하수처리장에서 미세입자를 보다 효율적으로 제어하기 위한 도구를 제공하고자 하였다. 개발 모델에서는 수처리 계통에서의 4개 단위공정(1차침전지, 생물반응조, 2차침전지, 및 총인처리시설)을 고려하고, 슬러지처리 계통은 농축, 소화, 탈수 공정 등의 다중 공정을 통합한 단일 공정으로 모의한다. 모의 대상 미세입자는 TiO₂ (nano-TiO₂)로서, 수중에서의 용해와 변환은 미미하므로 부유성 고형물과의 부착 기작만을 고려하였다. 부유성고형물에의 nano-TiO₂ 부착 기작은 고-액상 간 평형가정에 기반한 겉보기분배계수(Kd)를 매개변수로 반영하였으며 정상상태에서의 미세입자의 농도 및 부하를 공정별로 계산할 수 있도록 하였다. 아울러 개발 모델 구동의 편의를 위하여 MS 엑셀기반 사용자 인터페이스를 제작하였다. 개발 모델을 이용하여 주요 운전인자인 고형물체류시간(Solid Retention Time, SRT)이 nano-TiO₂ 제거효율에 미치는 영향을 파악하였다.

• Parasites, Hosts and Diseases
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• 제47권2호
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• pp.93-102
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• 2009

Malaria is a major cause of death in tropical and sub-tropical countries, killing each year over 1 million people globally; 90% of fatalities occur in African children. Although effective ways to manage malaria now exist, the number of malaria cases is still increasing, due to several factors. In this emergency situation, prompt and effective diagnostic methods are essential for the management and control of malaria. Traditional methods for diagnosing malaria remain problematic; therefore, new technologies have been developed and introduced to overcome the limitations. This review details the currently available diagnostic methods for malaria.

• 동아시아식생활학회지
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• 제14권6호
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• pp.640-645
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• 2004

An eight-week-old male ICR mouse, which was induced with acute alcohol and sub-acute alcohol poisoning condition, was administered with bohee tea(Camelia sinensis L) extract. Under the inducement of the sub-acute alcohol poisoning condition, no considerable differences could be found in the blood alcohol concentration of the positive control group and the bohee tea group(p<0.05). The GOT activity of the three groups: bohee tea, Drink, and Alcodex decreased than that of the normal control group(9.064±4.687 unit)(p<0.05). In addition, the blood GOT activity of the dark green tea group dropped by 81.44% compared with that of the positive control group. On the other hand, the blood GTP activity of the bohee tea group decreased by 5.2% as opposed to that of the positive control and the Drink that decreased by 7.5% as opposed to that of the positive control. The hepatic ADH activity of the bohee tea increased by 22.7%, as opposed to that of the positive control group. The Drink, however, had an increase rate of 33.6%. In the case of the hepatic ALDH activity of the liver, no significant differences were ever recorded among all groups, except for the positive control group. Due to an intake of bohee tea extract, the hepatic ALDH activity decreased by 77.27% which could not be seen in the positive control group. However, Drink and A1codex had a decrease could be seen(p<0.05).

• 디지털융복합연구
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• 제13권6호
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• pp.247-256
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• 2015

본 연구는 키네틱 발광 오브젝트 제어 장치 및 이를 위한 방법에 관한 것으로 BMW Korea의 의뢰를 받아 제작하게 된 작품이다. 연구에서 설명하고 있는 작품은 BMW Korea 드라이빙센터의 설치를 목적으로 하고 있으며 현제 프로토타입 제작이 완료된 상태이다. 본 연구는 다수의 그룹으로 이루어진 다수의 오브젝트와, 그것을 이용하여 형상을 나타내기 위해 다수의 그룹 각각에 대응하는 메인 제어 신호를 전송하는 메인제어부와, 메인 제어신호에 따라 상기 다수의 그룹 중 대응하는 그룹의 오브젝트 각각에 대응하는 서브 제어 신호를 전송하는 다수의 서브제어부와, 서브 제어 신호에 따라 다수의 오브젝트 각각과 연결된 와이어의 길이를 조절하는 다수의 구동부를 포함하는 것을 특징으로 하는 키네틱 발광 오브젝트 제어 장치와 이에 따른 방법에 관한 연구이다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.637-640
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• 2005

In the development of a electronic system for a optical payload comprising mainly EOS(Electro-Optical Sub-system) and PDTS(Payload Data Transmission Sub-system), many aspects should be investigated and discussed for the easy implementation, for th e higher reliability of operation and for the effective ness in cost, size and weight as well as for the secure interface with components of a satellite bus, etc. As important aspects the interfaces between a satellite bus and a payload, and some design features of the CEU(Camera Electronics Unit) inside the payload are described in this paper. Interfaces between a satellite bus and a payload depend considerably on whether t he payload carries the PMU(Payload Management Un it), which functions as main controller of the Payload, or not. With the PMU inside the payload, EOS and PDTS control is performed through the PMU keep ing the least interfaces of control signals and primary power lines, while the EOS and PDTS control is performed directly by the satellite bus components using relatively many control signals when no PMU exists inside the payload. For the CEU design the output channel configurations of panchromatic and multi-spectral bands including the video image data inter face between EOS and PDTS are described conceptually. The timing information control which is also important and necessary to interpret the received image data is described.

• Animal Bioscience
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• 제35권1호
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• pp.64-74
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• 2022

Objective: This study was conducted to investigate the effects of dietary multi-strain probiotic (MSP) (Bacillus coagulans Unique IS2 + Bacillus subtillis UBBS14 + Saccharomyces boulardii Unique 28) on performance, gut morphology and expression of nutrient transporter related genes in broiler chickens. Methods: A total of 256 (4×8×8) day-old CARIBRO Vishal commercial broiler chicks of uniform body weight were randomly distributed into four treatments with 8 replicates each and having eight chicks in each replicate. Four dietary treatments were T₁ (negative control-basal diet), T₂ (positive control-antibiotic bacitracin methylene disalicylate at 20 mg/kg diet), T₃ (MSP at 10⁷ colony-forming unit [CFU]/g feed), and T₄ (MSP at 10⁸ CFU/g feed). Results: During 3 to 6 weeks and 0 to 6 weeks, the body weight gain increased significantly (p<0.05) in T₃ and T₄ groups. The feed intake significantly (p<0.05) reduced from T₁ to T₃ during 0 to 3 weeks and the feed conversion ratio also significantly (p<0.05) improved in T₃ and T₄ during 0 to 6 weeks. The humoral and cell mediated immune response and the weight of immune organs were also significantly (p<0.05) improved in T₃ and T₄. However, significant (p<0.05) dietary effects were observed on intestinal histo-morphometry of ileum in T₃ followed by T₄ and T₂. At 14 d post hatch, the relative gene expression of glucose transporter (GLUT5), sodium-dependent glucose transporter (SGLT₁) and peptide transporter (PepT₁) showed a significant (p<0.05) up-regulating pattern in T₂, T₃, and T₄. Whereas, at 21 d post hatch, the gene expression of SGLT₁ and PepT₁ was significantly (p<0.05) downregulated in MSP supplemented treatments T₃ and T₄. Conclusion: The supplementation of MSP at 10⁷ CFU/g diet showed significant effects with improved performance, immune response, gut morphology and expression of nutrient transporter genes. Thus, the MSP could be a suitable alternative to antibiotic growth promoters in chicken diets.