• 한국의학물리학회지:의학물리
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• 제21권4호
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• pp.340-347
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• 2010

단층치료기(TomoTherapy$^{(R)}$)를 이용한 방사선 치료에서 환자별 정도관리인 DQA (delivery quality assurance)는 보통 이온 전리함과 필름을 이용한다. DQA의 결과는 치료계획장비인 TomoPS (Tomo Planning Station)를 이용하여 분석하게 되는데 필름을 이용한 2차원 선량분포의 비교는 감마인덱스 분석을 사용한다. 감마인덱스를 이용한 비교는 3%/3 mm와 같은 기준을 사용하여 이 기준을 통과한 비율(pass rate)이 허용 값보다 크게 되는지 확인한다. TomoPS는 pass rate 값을 정량적으로 계산해주는 기능이 없다. 본 논문에서는 TomoPS 감마인덱스 분석의 pass rate를 정량적으로 계산하는 방법을 제시하고 이를 계산해주는 프로그램인 PassRT를 개발하였다. PassRT의 검증을 위해 I'mRT MatriXX (IBA Dosimetry, Germany)를 사용하여 측정한 세기조절방사선 치료를 받은 환자의 환자별 정도관리 자료와 필름을 사용한 DQA 자료를 사용하였다. 두 가지 종류의 자료에 대해 PassRT로 계산한 pass rate를 OmniPro I'mRT (IBA Dosimetry, Germany)프로그램으로 계산한 pass rate와 비교하였다. MatriXX를 이용하여 측정한 자료의 비교결과 평균오차 0.00%, 표준편차 0.01%, 최대오차 0.04%였고, 필름의 결과는 평균오차 0.00%, 표준편차 0.02%, 최대오차 0.02%였다. 관심영역이 $24.3{\times}16.6cm^2$ 보다 작은 경우 본 논문에서 제시한 방법으로 감마인덱스 분석의 pass rate를 소수점 첫째자리 까지 정확하게 계산할 수 있어서 보다 정확한 단층치료기의 DQA에 도움이 될 것으로 생각된다.

• 소성∙가공
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• 제27권4호
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• pp.222-226
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• 2018

Severe plastic deformation (SPD) is a promising method for drastically enhancing the mechanical properties of the materials by grain refinement of metallic materials. However, inhomogeneous deformation during the SPD process results in the inhomogeneous microstructure of the SPD-processed material. We manufactured cylindrical copper specimens of 42 mm in diameter with ultrafine grains (UFG) using an equal channel angular pressing (ECAP) to figure out the relationship between homogeneous microstructure and the number of the processing passes. Two specimens, which are ECAP-processed 4 times (4pass) and 6 times (6pass) each with Route Bc, are prepared for comparison of mechanical properties and microstructure. The results show that the mechanical properties of the two specimens (4pass and 6pass) are similar. Moreover, both the specimens show highly enhanced mechanical properties. The 4pass specimen, however, shows inhomogeneity in hardness distribution, while the 6pass specimen shows a homogeneous distribution. Microstructure analysis reveals that the 4pass specimen has an inhomogeneous microstructure with incompletely refined grain structure. This inhomogeneity of the 4pass specimen could be explained by the circumferential rotation during ECAP process.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.600-603
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• 2000

In the high carbon steel wire drawing process, the wire temperature increases as the drawing speed is faster in order to increase the production rate in the shop floor. The rapid temperature rise causes the wire fracture in the dry wire drawing process. So, in this paper, the isothermal pass schedule program, which includes the calculation method of wire temperature at each pass, is proposed to prevent the wire fracture due to the temperature rise. Using the isothermal pass schedule program, it is newly proposed the pass schedule design system that prevents the cup-cone defects, improves the elongation of the final products and assures further deformation. As a result, the temperature rise of the wire was decreased and the production rate of the final product is remarkably grown up according to the increase of the final drawing speed than that of the conventional process. Also, the proposed pass schedule design system could give a useful information to the process designer who would design the high carbon steel wire drawing process.

• 전기전자학회논문지
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• 제5권2호
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• pp.182-189
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• 2001

Single-pass VDD 심장 박동기(pacemaker)는 하나의 리드만 이식하는 수술 과정의 단순함과 하나의 리드만으로 심방 탈분극파를 적절히 검출하여 심방-심실 탈분극의 연속성(A-V sequence)을 이를 수 있다는 이유로 널리 사용되고 있으나, 검출의 신뢰도에 대해서는 여전히 논의의 대상이 되고 있다. 본 논문에서는 논의의 대상이 되고 있는 심방 탈분극파 검출을 개선하기 위하여 자동화된 심장 박동기 심파 검출 알고리즘을 9명의 환자로부터 얻은 Single-pass VDD 심파에 적용하고, 실제 심파 검출과정에서의 동작 특성을 관찰하였다. 자동화된 검출 알고리즘은 최근에 검출된 두 개의 intrinsic 탈분극파 진폭의 평균치를 계산하여 그 평균치의 50%로 검출 문턱치를 매 박동마다 조정하는 매우 단순한 방법으로, 자동화된 검출 알고리즘의 핵심인 문턱 전압 검출치의 자동적 조정만으로도 Single-pass VDD 심방 탈분극파 검출을 개선할 수 있음을 확인하였다.

• 대한통합의학회지
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• 제8권2호
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• pp.131-138
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• 2020

Purpose : The purpose of this study was to investigate the effects of the frequency band pass filter on the P300 event-related potential in the working memory. Methods : The subjects were 20 women in their 20s who applied for participation in the experiment. Event-related potentials (ERPs) were elicited using 3-back tasks for the working memory, and were recorded from Fz, Cz, and Pz scalp electrodes. The high-pass filters were set to 0.01, 0.1, and 0.3 Hz for analysis purposes, and the low-pass filters were set to 30 and 15 Hz. The 3-back task was presented for a total of 100 times, among which 30 times were designated for the target stimulation (a matched number) and 70 times for the non-target stimulation (an unmatched number). The temporal interval between each stimulation was set at 1 second, while each time duration was randomly presented between 2 to 4 seconds. ERP were analyzed for the P300 recorded from Fz, Pz and Cz scalp electrodes. Results : Latency and amplitude had no significant interaction effects in both the high- and low-pass filters. For the main effects, the latency and amplitude of the P300 event-related potential had no significant difference in the high-pass filters, but the latency had a significant difference in the low-pass filter of Fz, and the amplitude had a significant difference in the low-pass filter of Pz. Conclusion : The results of this study showed that the less than 0.3 Hz high filters had no effects on the differences between the latency and amplitude of the P300 event-related potential in the working memory. The 30Hz low-pass filter, however, was found to be useful for recording the P300 event-related potential in the working memory.

• 한국전문물리치료학회지
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• 제14권1호
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• pp.64-73
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• 2007

The purpose of this study was to find any correlations among Postural Assessment Scale for Stroke (PASS), Modified Barthel Index (MBI), Tone Assessment Scale (TAS), Motor Assessment Scale-Gait (MAS-G), Fugl Meyer-Balance (FM-B), and to predict MBI from subscales of the PASS. The subjects were 41 stroke patients of the Korea National Rehabilitation Center in Seoul. The main outcome measures were postural control (PASS), gait (MAS-G), Balance (FM-B), Tone (TAS), ADL (MBI). The data was analyzed using the Pearson product correlation. PASS scale was used between other clinical and instrumental indexes, multiple stepwise regression analyses were performed to identify prognostic factors for ADL incline, and Cronbach's alpha coefficient was used to identify internal consistency on PASS scale. The results of this study areas follows: 1. The highest level was sitting without support, the lowest level was standing on paretic leg on PASS scale. The highest level was chair/bed transfer, the lowest level was bathing on MBI. 2. All items of the PASS, except postural tone were significantly correlated with Gait, Balance, MBI (p<.01), 3. The Internal Consistency (Cronbach's alpha coefficient=.85) was very high, indicating that the PASS is homogeneous and is likely to produce consistent response. Furthermore, the sums of maintaining position items and of changing-position items were strongly correlated (r=.64, p<.05) and there were significant correlations between sums of PASS, sums of maintaining position items (r=.87, p<.01), and changing-position items (r=.93, p<.01). 4. The standing without support of the PASS items was the strongest variance ($R^2$=.85) of the predicting ADL function. These findings provide strong evidence of the predictive value of the postural control on gait, Balance, ADL function in stroke patients and to can provide a reference for the successful therapeutic program and more improved functional recovery.

• 한국재료학회지
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• 제21권6호
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• pp.320-326
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• 2011

Flat rolling of wire is an industrial process used to manufacture electrical flat wire, medical catheters, springs, piston segments and automobile parts, among other products. In a multi-step wire flat rolling process, a wire with a circular crosssection is rolled at room temperature between two flat rolls in several passes to achieve the desired thickness to width ratio. To manufacture a flat wire with a homogeneous microstructure, mechanical and metallurgical properties with an appropriate pass schedule, this study investigated the effect of each pass schedule (1stand ~ 4stand) on the microstructures, mechanical properties and widths of cold rolled high carbon steel wires using four-pass flat rolling process. The evolutions of the microstructures and mechanical properties of the widths of cold rolled wires during three different pass schedules of the flat rolling process of high carbon wires were investigated, and the results were compared with those for a conventional eight-pass schedule. In the width of cold rolled wires, three different pass schedules are clearly distinguished and discussed. The experimental conditions were the same rolling speed, rolling force, roll size, tensile strength of the material and friction coefficient. The experimental results showed that the four-pass flat cold rolling process was feasible for production of designed wire without cracks when appropriate pass schedules were applied.

• 한국ITS학회 논문지
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• 제15권1호
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• pp.52-65
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• 2016

2007년 전국적으로 개통된 하이패스(Hi-pass)의 이용률은 70%에 육박하고 있다. 본 연구에서는 현재 하이패스 이용률이 약 70%에 이르고 있는 상황에서 기존 하이패스 이용자들의 편의성과 만족도를 높일 수 있는 방안을 찾고자 수정 중요도-만족도 분석(Modified Importance-Performance Analysis, M-IPA)을 수행하였다. 서비스 분석에서 주로 사용되었던 M-IPA 기법의 경우 지역, 계층, 성별 등 다양한 유형별 특성 파악 및 각 유형별 개선 전략 수립이 가능하다는 장점을 가지고 있다. M-IPA 수행 결과 '무정차 납부'와 '통행요금 연계 할인'항목의 경우 중점 개선 항목으로 도출되었다. '무정차 납부'항목의 개선을 위하여 하이패스 이용수요에 맞는 하이패스 톨 부스의 운영 및 영업소 전후 진출입로를 고려한 하이패스 부스의 위치 선정 등의 개선이 필요한 것으로 도출되었다. 또한,'통행요금 연계 할인'의 항목의 경우 현재 하이패스 이용 시 통행요금 할인이 이루어지고 있으나, 이에 대한 인식이 부족하여 홍보가 필요한 것으로 나타났다. 본 연구를 통하여 하이패스 이용자들의 만족도를 개선시켜 하이패스 이용률을 제고시킬 수 있는 방안 도출을 위한 기초자료로 활용할 수 있을 것으로 기대된다.

• 한국수자원학회논문집
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• 제49권9호
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• pp.799-807
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• 2016

본 연구는 기상이변과 도시열섬현상으로 국지성 호우가 잦아져 도시침수피해가 매년 반복되고 있으며, 건기시에는 비가 모자라 지하수 부족으로 이어져 하천 건천화 현상이 빈번히 발생하고 있어 이를 해결하고자 "도시침수 저감을 위한 by-pass 빗물침투성 우수관거"를 제안한다. 집중호우로 확률년수 이상의 호우발생시 관거를 확대 교체하지 않고 기존우수 관거를 그대로 사용하며 배제시스템과 연계하여 by-pass 빗물침투성 우수관거를 설치하여 본 연구지역 대한민국 서울특별시 강남구 강남역사거리 지역 3.07 ha에서 관거확대공사와 비교시 평균 27백만원(44%) 공사비절감 및 기존 우수관거 유지로 별도의 우수처리 대책이 불필요하다. "도시침수 저감을 위한 by-pass 빗물침투성 우수관거"는 여름철 확률년수 이상의 비가 오더라도 by-pass관로를 통하여 통수능력을 증가시키며, 봄, 가을에 내리는 소량의 비는 by-pass 침투공을 통하여 전량 지중 수자원 확보에 기여한다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 추계학술대회 논문집
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• pp.46-49
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• 2008

Drawing process of the high carbon steel wire with high speed is usually performed at room temperature using multi pass. Tn the multi pass drawing, temperature rise affects the mechanical properties of the final product. The excessive temperature rise during the deformation promotes the occurrence of delamination, and deteriorates the torsion property and durability of wire. This paper investigates the occurrence of delamination in the wire through the torsion test and the evaluation of wire temperature. The excessive wire temperature ieads to the occurrence of delamination. Based on the calculation of the wire temperature, a new pass schedule, that can prevent the delamination due to the excessive wire temperature rise, is designed through the isothermal pass schedule.