• 제목/요약/키워드: Combined study

검색결과 11,660건 처리시간 0.042초

경쟁적 전력시장에서 복합화력발전의 입찰전략에 대한 연구 (A Study on the Bidding Strategies of Combined Cycle Plants in a Competitive Electricity Market)

  • 김상훈;이광호
    • 전기학회논문지
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    • 제58권4호
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    • pp.694-699
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    • 2009
  • Combined cycle plants which feature distinct advantages for power generation such as fast response, high efficiency, environmental friendliness, fuel flexiblity represent the majority of new generating plant installations across the globe. Combined cycle plants have different operating modes where the operating parameters can differ greatly depending which mode is operating at the time. This paper addresses the bidding strategy model of combined cycle plants in a competitive electricity market by using a characteristic of multiple operating modes of combined cycle plants. Simulation results of case studies show that an operating mode among multiple ones is selected strategically in generation bidding for more profit of generation company.

Interruption analysis of the SFCL-combined DC circuit breaker system using current-limiting technology

  • Kim, Jun-Beom;Jeong, In-Sung;Choi, Hye-Won;Choi, Hyo-Sang
    • 한국초전도ㆍ저온공학회논문지
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    • 제18권4호
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    • pp.30-34
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    • 2016
  • In this study, a SFCL-combined DC circuit breaker system was proposed by applying the current-limiting technology for DC circuit breaking. The SFCL-combined circuit breaker system consists of a mechanical DC circuit breaker combined with superconductors. To ensure the reliable structure and operation of the SFCL-combined circuit breaker system, a simulation grid was designed using the EMTDC/PSCAD program, and simulation was conducted. The results showed that the SFCL-combined DC circuit breaker system with superconductors limited the maximum fault current by 37%. In addition, the burden on the DC circuit breaker was decreased by 87%.

소 발굽질병에 대한 水針의 治療效果 (The Therapeutic Effect of Aquapuncture on Bovine Foot Rot)

  • 류재홍;송근호;김덕환;김명철;신상태;조성환
    • 한국임상수의학회지
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    • 제19권2호
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    • pp.115-120
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    • 2002
  • To clarify the therapeutic effect of aquapuncture therapy on bovine foot rot, the experimental cattle were divided into control (conventional treatment), aquapuncture and combined treatment groups. Each group was composed of 6 Holstein cows with bovine foot rot. In the present study, the change in grade of lameness, total leukocyte counts, N/L. ratio, mean recovery rates (days) and histopathological changes of interdigital tissue before and after treatment were evaluated. The grade of lameness was decreased by treatment in each group, with the decreasing in order of combined > aquapuncture > control group. In change of total peripheral blood leukocyte counts, the tendency of decrease was found. Significances were detected on 9th day (P < 0.05) in control, on 6th day (P < 0.01) in aquapuncture group, and on 3rd (P < 0.05) and 6th day (P < 0.05) in combined group, respectively. In addition, significances were detected on 3rd and 6th day in aquapuncture, and on 3rd day in combined group by comparison with that of control, respectively. N/L ratio was decreased by therapy in each group with the decreasing in order of combined > aquapuncture ) control group. Significances were detected on 6th day (P < 0.01) between aquapuncture and combined groups. The mean recovery rates(days) were rapid with the decreasing in order of combined > acuapuncture > control group. In histopathological findings of interdigital tissue, the findings of inflammation and hemorrhage were not observed after treatment in each group. In conclusion, it was thought that aquapuncture and combined therapy was very effective on treatment of bovine foot rot.

콘크리트 구조물의 단일 및 복합열화 환경하에서의 염소이온 확산특성 (Diffusion Characteristics of Chloride ion under Single and Combined Attacks in Concrete Structures)

  • 오병환;강의영;인광진;이성규;서정문
    • 콘크리트학회논문집
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    • 제14권5호
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    • pp.708-717
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    • 2002
  • 해안 등 열악한 환경에 노출되는 구조물들의 건설이 증가되면서 구조물의 내구성 문제가 심각해지고 있다. 특히, 염해만이 아니라 염해와 황산염 그리고 중성화 등 복합작용에 의한 열화문제는 아직도 연구된 바가 거의 없는 실정이다. 따라서, 본 연구에서는 염해와 황산염 및 중성화가 복합된 환경하에서 콘크리트 구조물의 성능저하 현상을 살피고 이들의 상호작용과 영향을 실험적으로 구명하는데 그 목적을 두고 있다. 이를 위해서 단일 및 복합열화 실험을 포괄적으로 수행하였다. 본 연구결과, 염소이온 단일열화시 보다 황산염 또는 황산염과 중성화가 복합되었을 경우의 열화현상이 더 두드러졌으며, 모든 열화조건에서 표면염소이온의 농도는 시간에 따라 증가하고 반면에 확산계수는 시간에 따라 감소하는 경향을 나타냈다. 표면염소이온 농도는 복합열화에서 더 증가하며 특히 염소이온 확산계수는 염해와 황산염 2중 복합열화시 더 커지고 여기에 중성화가 복합될 경우 더욱 커지는 것으로 나타났다. 따라서, 해안 구조물과 같이 염해와 황산염 및 중성화가 복합될 경우 염소이온의 침투가 더욱 커져 이들의 합리적인 고려가 필요한 것으로 나타났다.

The effectiveness of group combined intervention using animal-assisted therapy and integrated elderly play therapy

  • Kil, Taeyoung;Kim, Hak-man;Kim, Minkyu
    • Journal of Animal Science and Technology
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    • 제61권6호
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    • pp.371-378
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    • 2019
  • The purpose of this study was to investigate the effects of group combined intervention that combined animal-assisted therapy and integrated elderly play therapy on the depression, self-esteem, and emotional expression of geriatric patients residing in nursing homes. This was achieved by providing cognitive, physical, and emotional activities and social interaction at the same time. The group combined intervention method was applied to twelve elderly patients (six in the control group, six in the experimental group) aged 65 or older who live in a nursing home for the elderly in C province, from May 3, 2019 to June 21, 2019, for a total of 8 times (once a week, 50 minutes at a time). The quantitative evaluation was analyzed through SPSS 21.0 for comparison before and after the program was implemented, using the Korean version of the depression and the self-esteem scale. The qualitative evaluation compared emotional expression pre-test and post-test. The major results of the study were as follows: First, the group combined intervention was effective in reducing depression levels of the experimental group among the elderly patients. Second, it was effective in improving the self-esteem of the experimental group among the elderly patients. Third, it showed a significant difference in the emotional expression of the experimental group among the elderly patients. Therefore, it was found that group combined intervention reduces depression and improves self-esteem and emotional expression of the elderly. Based on these results, it is hoped that this study will be a cornerstone in the development of concrete programs for the benefit of elderly patients living in facilities.

개구부가 있는 밀폐공간내 화재의 복합열전달 및 연소가스 분석에 관한 연구 (A Study on the Combined Heat Transfer and Analysis Fire Induced Combustion Gas in a partially Open Enclosure)

  • 박찬국;추병길;김철
    • 한국화재소방학회논문지
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    • 제11권1호
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    • pp.21-35
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    • 1997
  • The natural convection and combined heat transfer induced by fire in a rectangular enclosure is numerically studied. The model for this numerical analysis is partially opened right wall. The solution procedure includes the standard k-$\varepsilon$ model for turbulent flow and the discrete ordinates method (DOM) is used for the calculation of radiative heat transfer equation. In numerical study, SIMPLE algorithm is applied for fluid flow analysis, and the investigations of combustion gas induced by fire is performed by FAST model of HAZARD I program. In this study, numerical simulation on the combined naturnal convection and radiation is carried out in a partial enclosure filled with absorbed-emitted gray media, but is not considered scattering problem. The streamlines, isothermal lines, average radiation intensity and kinetic energy are compared the results of pure convection with those of the combined convection-radiation, the combined heat transfer. Comparing the results of pure convection with those of the combined convection-radiation, the combined heat transfer analysis shows the stronger circulation than those of the pure convection. Three different locations of heat source are considered to observe the effect of heat source location on the heat transfer phenomena. As the results, the circulation and the heat transfer in the left region from heating block are much more influenced than those in the right region. It is also founded that the radiation effect cannot be neglected in analyzing the building in fire. And as the results of combustion gas analysis from FAST model, it is found that O2 concentration is decreased according to time. While CO and CO2 concentration are rapidly increased in the beginning(about 100sec), but slowly decreased from that time on.

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탁리화중탕(托裏和中湯)이 암세포(癌細胞) 및 면역세포(免疫細胞)에 미치는 실험적(實驗的) 효과(效果) (Experimental Effects of Taklihwajung-Tang on the Proliferation of Cancer Cells and Immunocytes)

  • 박수연;김종한;최정화;이준헌
    • 한방안이비인후피부과학회지
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    • 제19권1호
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    • pp.103-114
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    • 2006
  • Objective : The purpose of this study was to investigate effects of Taklihwajung-Tang on the proliferation of cancer cells land immunocytes focusing around combined effects of anticarcinogen. Materials and Method : We used Taklihwajung-Tang extract(THT) with freeze-dried, 8wks-old male balb/c mice and cancer cell lines(L1210, S-180) for this study. The proliferation of cells was tested using a colorimetric tetrazoliun assay(MIT assay). Results and Conclusion : The results of this study were obtained as follow ; 1. THT was significantly showed cytotoxicity on the L1210 cell lines and S-180 cell lines. 2. THT was significantly increased in the proliferation of thymocytes and splenocytes in vitro. 3. In combined effects of THT and vincristine(0.005mg/kg), THT was significantly inhibited proliferation of S-180 cell lines compared with positive control group. 4. In combined effects of THT and vincristine(0.005mg/kg), THT was significantly decreased in the weight of sarcoma compared with positive control group. 5. In combined effects of THT and vincristine, THT was significantly inhibited the hematological side reaction compared with positive control group. The present author thought that THT had action of anti-cancer and immune-activity, and in combined effects of vincristine, THT had recoverable effects on damage by anticarcinogen.

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조선전기 당(堂)·실(室) 결합 건축의 가구특성 분석 -방형 평면의 맞배직교형 지붕 가구를 중심으로- (A Study on the Structure of Combined Architecture of Dang and Sil in the Early Joseon Dynasty -Focusing on the Rectangular Plan and the Gable Roof Meeting at Right Angle-)

  • 김버들;이종서
    • 건축역사연구
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    • 제26권2호
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    • pp.31-42
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    • 2017
  • This study investigates how the spatial recognition structure is emerging through the case of rectangular plan combined with a combination of Dang-Sil(堂室) and Gong(工) shape roof, and identifies a type of architecture in the early Joseon Dynasty that has never been revealed. The conclusion of this study is as follows. First, the Dang and the Sil are connected to each other, but the architectural elements such as pillars, frame, and windows are distinguished and appear as separate buildings. Second, the distinction between Dang and Sil is evident by the difference in the number of ridges and the shape of the roof. In addition, the roof and roof framework of the independent rooms and the rooms were common in the right angled architecture where the direction and the expandability of each structure were maintained. Third, the construction of the Dang-Sil combined structure, in which two or more structure frameworks were combined with the rectangular combined flat roof structure, gradually changed into a single structure with a single ridge. Fourth, this change means that people of the early Joseon Dynasty recognized the Dang and Sil as separate architecture, but the strict sense of spatial separation has disappeared over time.

경두개직류자극을 결합한 동적 신장운동이 축구선수의 다리 근활성도와 점프수행력에 미치는 영향 (Effects of Dynamic Stretching Exercise Combined with Transcranial Direct Current Stimulation on Lower Extremity Muscle Activity and Jump Performance in Soccer Player)

  • 김제호
    • 대한통합의학회지
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    • 제7권4호
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    • pp.273-282
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    • 2019
  • Purpose : The purpose of this study was to provide the effective method for exercise therapy in soccer player. Methods : 30 soccer players were recruited for subjects. The subjects were divided to dynamic stretching exercise combined tDCS (Group I), dynamic stretching exercise combined Sham-tDCS (Group II) of which 15 subjects were randomly allocated. The subjects were given 3 hour of soccer skill and performance and additionally given 20 minutes of dynamic stretching exercise combined tDCS and sham-tDCS for each group, five times a week, for 6 weeks. Their muscle activity and jump performance were analyzed before the intervention. After 6 weeks of the intervention, the mentioned parameters were measured once more for between-group analysis. Results : Comparative analysis of the muscle activity and jump performance between the groups I and groups II showed statistically significant difference. Conclusion : Such results revealed that dynamic stretching exercise combined with tDCS is effective in muscle activity and jump performance. Based on the current study, more effective program is to be proposed for neurologic and musculoskelectal disorder as well as soccer player. Based on the current study, studies that incorporates various combine of variable is required for development of effective tDCS program.

과학기술과 결합된 패션디자인의 기능성에 관한 연구 (A Study on Functionality of Fashion Design Combined with Technology)

  • 권기영
    • 한국의류학회지
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    • 제28권1호
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    • pp.88-99
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    • 2004
  • The purpose of this study is to observe the significance and symbolic meaning of fashion design which is combined with machines, and to develop excellent designs in aesthetic aspects. The method of this study analyzed the related documents and journal, fashion magazines. The results is as follows. The cyborg discourse and virtual human body in virtual world predict the existence of new human. In present times, up-to-date equipments such as wearable computer have begun to be built-in clothing based on technology, and these dress and ornaments influence on human's life gradually in practicality and ability. These equipments are divided as military affairs, medical treatment equipment, leisure, information access and communication, guard, and business assistance. And according to the kind of item, they are divided by headwear, clothing and accessory. The significance of clothing combined with machine is practical viewpoint, economical viewpoint and aesthetic viewpoint. And the symbolic meaning of these fashion combined machine with technology is dis-identity in digital society, dis-borderness between human and machine and the uncertainty of human being. Like this, the clothing which is combined with high-technology shapes its own unique and individual system. But, this must escape from the limit of medium system itself that is technology to become a future clothing for human, suggest new agenda about human and society, and confirm the human being's existence and identity continually.