결과 내 재검색





        검색결과 15

        2022.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        CFD was used to study the change in the operation of the governor to check the effect of response delay due to residual air in the governor cylinder, which adjusts the pump RPM of the Turbine Driven Aux. Feed Water Pump(TD AFWP) in the Nuclear power plant. As a result of analysis, as the amount of internal air increased, the time delay also increased proportionally, and a time delay of up to 0.2 sec. occurred. As in the theory, it was confirmed that the cylinder operation delay occurred depending on the presence or absence of a compressive fluid such as air, but the time delay wat not enough to significantly affect the pump operation.
        2021.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Four types of metal oxide semiconductor gas sensor arrays were used to observe the aroma and spoilage odor emitted during the ripening process of plum & banana fruits. All gas sensors showed a high correlation (R=0.82~0.90) with the olfactory. The TGS 2603 sensor showed a high correlation of 0.90 between the odor generated and sensory perception of smell in the process of ripening and decaying fruits. In addition, it showed a very high correlation of 0.91 with the decay rate of the plum sample, and the significance probability through one-way ANOVA was also less than 0.05, which confirmed it as an optimal gas sensor (TGS 2603). Principal component analysis was performed using all the data. The cumulative variability was 99.54%, which could be explained only by two principal components, and the first principal component was 95.11%, which was related to the freshness of the fruit. It was analyzed as fresh fruit in the negative(-) direction and decayed fruit in the positive(+) direction.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, by using a system analysis program(Fluid Flow), the correlation between the location where cladding damage occurs frequently inside the power plant seawater pipe and flow characteristics is analyzed, and the root cause and improvement plan are reviewed. As a result, it was confirmed that a high flow velocity occurred in the backwash piping(7.64m/s) and the front and rear ends of the flow control valve(5.93m/s). In addition, it was confirmed that cavitation occurs when the seawater level decreases below the saturated water vapor pressure at the rear end of the orifice. These areas are locations where the internal cladding damage occurs frequently in power plants, and the main cause of damage is considered to be excessive flow velocity and cavitation in the pipe. In order to solve this problem, improvement method such as installation of backwash pipe orifices, change of pipe shape at the front and rear end of flow control valve, and change of orifice type were derived.
        2020.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the past, the U.S. NRC(Nuclear Regulatory Commission) strictly required testing of the EDG for NPP through Reg.Guide 1.108 Rev 1. However, these test requirements acted as a deterioration and wear factor for diesel engines, and are now applying Reg.Guide 1.9 Rev 3, which relaxed regulatory requirements and improved performance monitoring. After applying the new regulatory guidelines in this study, the EDG analyzed the performance of the combustion chamber. As a result, there were no signs of deterioration or decreased performance of the current EDG. This is due to slow start, short operation time, the use of high quality fuel oil and proper maintenance. On the other hand, if the performance is proven, it is judged that proper period extension of cylinder maintenance is possible.
        2020.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The change in pressure measurement according to the low pressure tap blockage rate of the Venturi flowmeter used in domestic nuclear power plants was approached numerically. Blockage rates were modeled dividing by 1/10dT to the downstream side of the low pressure tab to identify differential pressure changes. As a result, differential pressure increased in proportion to the blockage rate, and there was no change in differential pressure measurement at 10 to 40 percent with relatively small blockage rate, but the error rate of 50% to 0.3% or higher was shown.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        2010년 구제역으로 많은 농가들이 피해를 입었으며, 발생원인과 바이러스 전파 과정에 대해서 명확한 원인과 근거를 찾을 수 없는 상태이다. 본 연구에서는 구제역의 발생에 있어서 불명확한 살처분 방지와 감염경로의 예측을 위한 지형적인 특성을 구명하고자, 2010년 경북지역을 대상으로 구제역이 발생한 농가 58개의 지형을 분류하였다. 분류요소는 농가가 위치한 고도, 경사도, 축사의 방향, 도로인접도, 마을인접도와 경사방향을 설정하여 발생농가의 지형적 자료를 각 항목에 분류하였다. 각 요소별 분류에서고도와 경사도, 하천인접도에서는 차이점을 나타내었으나, 축사방향 및 경사방향, 도로인접도, 마을인접도에서는 유사한 지형적인 특성을 보였다. 본 연구를 통하여 구제역 발생 농가만의 특수한 지형은 알수가 없었지만, 많은 변수들을 고려한 지형분류가 구제역 확산 방지와 예찰을 하기 위한 기초자료로 활용 될 수 있을 것으로 판단된다.
        2013.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        온실 및 식물공장 작물재배에 있어서 LED 광원과 작물생육에 관한 연구들은 활발히 진행 되고 있으나, LED광원과 식물에 병을 일으키는 식물병원균에 대한 연구들은 미흡하다. LED 광원은 이미 시설재배 혹은 식물공장에 설치되어 있으므로 LED광원으로 식물에 발생하는 병원균을 제어할 수 있다면 방제에 필요한 인적, 시간적 비용과 살균제 등과 같이 인체에 유해한 성분들의 사용을 감소시킬 수 있을 것으로 판단하여 LED광원에 대한 Botrytis cinerea의 균사생장을 조사하였다. 식물공장에서는 주로 엽채류를 재배하며 엽채류에는 여러 가지 곰팡이균들에 의한 질병 발병 가능성이 충분히 내재되어 있다. 병원균의 포자는 항상 작물재배지에 존재하고 있기 때문에 LED 광원이 식물병원균의 균사 생장을 억제 할 수 있다면, 식물공장내에서 작물재배에 효과적으로 이용할 수 있을 것으로 판단된다. 식물공장의 광원중 가장 많이 보편화되어 있는 LED 광원을 이용하여 B. cinerea의 균사 생장을 조사한 결과 Blue 광원에서 균사 생장이 억제되는 것을 관찰할 수 있었다. 이러한 결과는 식물공장내 LED의 비율과 광량의 적절하게 조절함으로써 식물병원균의 증식을 억제 할 수 있을 것으로 판단된다.
        2010.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문은 인간의 감성을 반영한 아이폰 기반의 3차원 미로 게임을 제시한다. 이를 위해서 2차원의 미로이미지를 입력받아서 골격선(skeleton) 추출 기술을 활용하여 이진화 된 최소의 데이터를 얻는다. 이 데이터를 이용하여 OpenGL ES를 활용한 3차원 미로 환경을 구축한다. 또한 인간의 감성에 영향을 미치는 시각·청각 요소들이 반영된 아이템을 배치하여 게임적인 흥미요소들을 추가한다. 시각적 요소에는 미로 텍스처의 색상과 밝기, 청각적 요소에는 OpenAL을 활용한 멀티사운드를 이용한다. 본 논문에서 제시하는 3차원 미로 게임은 기존의 2차원 미로 게임들과 달리, 스테이지 별로 시나리오를 구성하였으며 3차원으로 개발함으로써 게임의 현실성을 높일 수 있었다.
        2005.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to examine the effects of self-controlled learning using the (KR) feedback schedule versus the yoked KR on the acquisition and retention of balance training for individuals with hemiplegics. Sixteen hemiplegics were randomly assigned to either a self-controlled or yoked KR group. All subjects were ambulatory with or without an assistive device. The self-controlled group was provided with feedback whenever they requested it, whereas the yoked group had no influence on the feedback schedule. All subjects performed 10 acquisition trials and 10 retention trials the day after acquisition. The data were analyzed using an independent t-test and a Mann-Whitney U test. Participants in the self-controlled group achieved significantly more effective learning than the yoked group during the acquisition and retention test except anterior/posterior (AP) body sway. These results suggest that a feedback schedule which is controlled by the individuals with hemiplegics may be more effective in balancing training than a yoked KR which is not controlled by the subject.
        2014.12 서비스 종료(열람 제한)
        We studied clinical utility of open door laminoplasty with foraminotomy in CSM with multilevel radiculopathy. We divided into two groups; the first group underwent laminoplasty with formainotomy, and the second group underwent laminoplasty and multiple ant. approaches. In the first group, the JOA score increased from a preoperative 13.3 to postoperative 16.0 (range, 10 to 18), and in the second group from 12.8 to 15.5 (range, 10 to 18). However, the pre-operative VAS score was 6.1, 6.5 and, 2 weeks after surgery, had decreased to 2.4, 1.4, the last score was the same, 1.8, finally. The open door lami-noplasty with foraminotomy was easily performed and clinical profiles were similar to those for the laminoplasty and multi-ple anterior approach.
        2013.09 서비스 종료(열람 제한)
        The principle of treatment of type 2, 3 odontoid process fracture is controversial. The debate is in regard to which is effective between conservative treatment and surgery. We enrolled 41 patients with type 2, 3 odontoid process fracture from January 2007 to December 2011 at Chosun University Hospital. Patients in Group I (GI) received a halo vest and those in Group II (GII) underwent surgery by ant. screw fixation. The bone fusion was classified according to stable bone union, fibrous union, and unstable non-union. Patients in GI received halo vest for a mean period of 4.9 months and those in GII received a neck collar for a mean period of 3.8 months. Tweleve patients in GI and 17 patients in GII had stable bone union. Three patients in GI and two patients in GII had fibrous union. Five patients in GI and two patients in GII had non-union. The halo vest was a good conservative treatment for type 2, 3 odontoid process fracture : however, low bone fusion rate is a problem in particularly old age. However, ant. screw fixation is a better treatment in regard to short surgical time, short fusion time, and high bone fusion rate.
        2013.01 KCI 등재 서비스 종료(열람 제한)
        본 연구는 우리나라에서 가장 일반적인 중소규모의 비내진 상세를 가진 건축물을 대상으로, 노후도를 고려하여 내진성능을 평가하였다. 평가결과, 준공 후 24년이 경과되었으나 노후도는 대체로 양호한 것으로 평가되었고, 1차, 2차 내진성능평가는 기준지표를 만족하지 못하는 것으로 나타났다. 3차 내진성능평가에서는 층간변위비를 기준으로 목표성능은 만족하지만 보강이 필요한 것으로 판단되었다. 대상 건축물에 벽체보강, 가새보강, 댐퍼보강을 한 후 내진성능평가를 실시한 결과, 보강방법에 상관없이 층간변위비는 현저히 감소하여 즉시거주수준을 만족하는 수준으로 나타났다. 그러나 벽체보강의 경우 밑면전단력이 2배 이상 증가되어 기존기초에 대한 검토가 필요하다.