• 터널과지하공간
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• 제28권1호
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• pp.111-124
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• 2018

본 연구는 전세계적으로 활발하게 기술 개발 중인 네트워크형 복층 도로터널에서의 환기 설계를 위해 새롭게 요구되는 설계인자를 분석한다. 분류 및 합류부 지점에 존재하는 확폭구간에서 단면적의 변화에 따라 발생하는 충격손실계수를 결정하기 위해 전산유체역학(CFD)를 통한 수치해석 연구를 진행하였다. 수치해석에 사용된 모델은 실제 스케일을 반영하였고 이전의 선행 연구의 충격손실계수 값과의 비교분석을 통해 그 값의 신뢰성을 확보하였다. 수치해석 연구의 결과로 단면적비의 변화에 따른 충격손실계수 값을 도출해냈고 급확대부와 급축소부 두 경우 모두 이전의 선행 연구에서 제시된 충격손실계수 값보다 높게 계산되어졌다. 이는 네트워크형 복층 도로터널의 기하학적 구조의 특성이 충격손실계수에 미치는 영향이 크다고 판단된다. 따라서 본 연구의 결과 값은 앞으로 네트워크형 복층 도로터널의 환기 설계에 있어 좀 더 정확한 설계에 도움이 될 것으로 기대된다.

• Advances in nano research
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• 제8권4호
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• pp.323-333
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• 2020

In recent years, there has been an upsurge for the usage of buckling restrained braces (BRB) rather than ordinary braces, as they have evidently performed better. If the overall brace buckling is ignored, BRBs are proven to have higher energy absorption capacity and flexibility. This article aims to deliberate an economically efficient yet adequate type of all-steel BRB, comprised of the main components as in traditional ones, such as : (1) a steel core that holds all axial forces and (2) a steel restrainer tube that hinders buckling to occurr in the core; there is a more practical detailing in the BRB system due to the elimination of a filling mortar. An investigation has been conducted for the proposed rectangular-tube core BRB and it is hysteric behavioral results have been compared to previous researches conducted on a structure containing a similar plate core profile that has the same cross-sectional area in its core. A loss of strength is known to occur in the BRB when the limiting condition of local buckling is not satisfied, thus causing instability. This typically occurs when the thickness of the restrainer tube's wall is smaller than the cross-sectional area of the core plate or its width. In this study, a parametric investigation for BRBs with different formations has been performed to verify the effect of the design parameters such as different core section profiles, restraining member width to thickness ratio and relative cross-sectional area of the core to restrainer, on buckling load evaluation. The proposed BRB investigation results have also been presented and compared to past BRB researches with a plate profile as the core section, and the advantages and disadvantages of this configuration have been discussed, and it is concluded that BRBs with tubular core section exhibit a better seismic performance than the ones with a plate core profile.

• 한국실내디자인학회논문집
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• 제24권2호
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• pp.125-133
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• 2015

Gaze induction characteristics in space vary depending on characteristics of spatial components and display. This study analyzed dominant eye-fixation characteristics of three zones of department store space. Eye-fixation characteristics depending on spatial components and positional relationship can be defined as follows. First, [**.jpg] was used as an extension in the process of storing the image photographed during image data processing for analysis in pixels and due to compressed storage of image data, the image produced with a clear boundary was stored in neutral colors. To remove this problem, the image used in operation was re-processed in black and white and stored in the [**.bmp] format with large capability, at the same time. As the result, the effort caused by unnecessary colors in the program operation process was corrected. Second, the gaze ratio to space area can be indicated as a strength of each gaze zone and when analyzing the gaze strength of the three zones, the left store was a zone with a "little strong" gaze strength of "102.8", the middle space was a zone with an "extremely weak" gaze strength of "89.6" and the right store was a zone with an "extremely strong" gaze strength of "117.2". Third, the IV section had a strong strength of gaze on the middle space and the right store and the V section showed a markedly strong strength of gaze on the left and right stores. This tendency was the same as the VI section with the strongest gaze strength and the right store had a little strong gaze strength than the left store.

• 한국안전학회지
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• 제27권3호
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• pp.153-160
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• 2012

Various social problems such as traffic congestion, car accidents and environmental problems(air pollution, noises etc.) have been happening in the Seoul metropolitan area that has the car oriented traffic system providing cars continuously. Along with this, the financial burden caused by current oil price anxiety made paradigm shift from caroriented to public transportation-oriented. Its typical example is an arterial branch bus system changing(bus lane through the center of main road) started in Seoul in July, 2004. But study on safety analysis of bus lane and characteristic of accidents are not sufficient enough to now. The bus lanes are expanded to provide roads for better traffic operation and accidents between buses and pedestrians or ordinary vehicles are considered main problems. This study divided each bus route of median bus lane(bus-only lane through the center of main roads) and bus lane at roadside by intersection and collected and analysed data about influence variables of bus accidents chosen in each section. We constructed a logistic model using collected data. As a result, bus lane at roadside are used by both buses and other kinds of vehicles differently from median bus lane and showed such characteristic in accident influence. Therefore access management to factors causing conflict and improvement of operation management are required. In case of median bus lane, the more buses moving general vehicle lane and traffic volume of section were, the more accidents happened. In case that stop line of center lane is not backward, view blocking of vehicles turning left caused accidents.

• 대한한방내과학회지
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• 제39권6호
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• pp.1168-1180
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• 2018

Objective: As the number of sarcopenic patients worldwide is increasing, the need for the treatment of sarcopenia is increasing. Ginseng has been reported to be a major herbal supplement. We tested whether red ginseng would be effective for sarcopenia using red ginseng preparation which can be easily obtained locally in Korea. Methods: 30 rats were randomly divided into three groups: the control group (n=10) (Group C), the group with Dexamethasone -induced sarcopenia (n=10) (Group D), and the group to which red ginseng was administered group after induced sarcopenia with Dexamethasone (n=10) (Group DH). Dexamethasone was intraperitoneally administered to group D and group DH for 7 days to make sarcopenic model. After that, the red ginseng tablets prepared by Korea Ginseng Corporation were diluted in distilled water and administered orally to the DH group for 2 weeks. Body weight and grip strength were measured 8 times during the experiment. At the end of the experiment, blood was collected by cardiac puncture. In addition, the tibialis muscle was extracted, a myofibril cross section was measured by immunohistochemical staining and MyHC (myosin heavy chain) was quantified by Western blotting. Results: The ratio of the area on myofibril cross-section showed significant differences after administration of the red ginseng tablet. Conclusions: Red ginseng has a significant effect on the recovery of myofibril cross-section on sarcopenia. This experiment will be helpful for future clinical studies on drug effects in sarcopennia.

• Structural Engineering and Mechanics
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• 제84권3호
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• pp.295-310
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• 2022

This paper proposes a modified bar simulation method for analyzing the shear lag effect of variable sectional box girder with multiple cells. This theoretical method formulates the equivalent area of stiffening bars and the allocation proportion of shear flows in webs, and re-derives the governing differential equations of bar simulation method. The feasibility of the proposed method is verified by the model test and finite element (FE) analysis of a simply supported multi-cell box girder with constant depth. Subsequently, parametric analysis is conducted to explore the mechanism of shear lag effect of varied sectional cantilever box girder with multiple cells. Results show that the shear lag behavior of variable box-section cantilever box girder is weaker than that of box girder with constant section. It is recommended to make the gradient of shear flow in the web with respect to span length vary as smoothly as possible for eliminating the shear lag effect of box girder. An effective countermeasure for diminishing shear lag effect is to increase the number of box chambers or change the variation manner of bridge depth. The shear lag effect of varied sectional cantilever box girder will get more server when the length of central flanges is shorter than 0.26 or longer than 0.36 times of total width of top flange, as well as the cantilever length exceeds 0.29 times of total length of box's flange. Therefore, the distance between central webs can adjust the shear lag effect of box girder. Especially, the width ratio of cantilever plate with respect to total length of top flange is proposed to be no more 1/3.

• 한국의류학회지
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• 제34권11호
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• pp.1779-1785
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• 2010

The experiment is designed to create some useful data on the dressed shapes that contribute to simulating the adaptability of clothes. We studied the dressed shapes of blouse with above-elbow sleeves and sleeveless according to five types of arm movement (basic posture, reach forward 45, 90, and reach lateral 45, 90) in the stand-posture. Experiments were conducted to understand the dressed shape through 3-D measurement Vivid 910 and to investigate the width, depth, area distribution and gap of the shape of blouses on the section map with a software program for 3-D shape analysis, Rapid Form 2004. The Data were analyzed by factor analysis. The results of this study are as follows: The ratio of depth per width in the stand-posture was lower than other arm movements and the reach lateral was higher than the reach forward. The gap of the upper body was a briefed 4 factor; front, front-side, back, and back-side. It was higher than the sleeveless with a change of the gap in the dressed blouse with above-elbow sleeves by arm movements per stand-posture. The divisional gap shows the adaptability of clothes according to the types of blouse and arm movements in the change of the ratio.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2003년도 봄 학술발표회 논문집
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• pp.853-860
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• 2003

Relationship between axial strain and volumetric strain of Light-Weighted Foam Soil (LWFS) are investigated. LWFS is composed of the dredged soil from offshore, cement and foam to reduce the unit weight and also increase compressive strength. For this purpose. the triaxial compression tests are carried out on the prepared specimens of LWFS with various conditions such as initial water contents, cement contents, and curing stresses, The test results of LWFS Indicated that the axial strain - volumetric strain relationship is almost linearity with increase cement contents and the unit weight but the relationship is non-linearity with decrease cement contents and the unit weight. In this study, it is found that assuming no change of cross section area of LWFS, axial strain occurring the poisson's ratio of zero, that the axial strain same to volumetric strain, steeply increases with decrease the unit weight, initial water content, and cement contents.

• Advances in pediatric surgery
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• 제4권2호
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• pp.144-147
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• 1998

The sacrococcygeal region is the frequent site for meningocele, congenital dermal sinus and pilonidal cyst. From May 1995 to July 1998, we have treated 8 neonatal patients with an abscess in the sacrococcygeal area. The mean age at onset was 8.3 days with a range from 6 to 11 days. The sex ratio was 5:3 with male preponderance. Mild fever was the only systemic symptom. Ultrasonogram revealed a slightly hypo echoic lesion in the subcutaneous tissue which became more hypoechoic with time. Pus cultures showed $Staph.$ $aureus$ in 7 patients, two of them had mixed infection with $E.$ $coli$ and other 2 had methicillin-resistant $Staph.$ $aureus.$ The remaining one patient had a mixed infection with $Klebsiella$ and $Proteus.$ Histopathological examination revealed non-specific granuloma and fibrinoid necrotic debris. All patients were easily treated by incision, drainage and proper antibiotics.

• 한국유체기계학회 논문집
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• 제16권1호
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• pp.5-10
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• 2013

The performance of screw air compressor is affected by rotor profile, lobe number, air end wrap angle, rotor L/D ratio, suction and discharge ports, revolutions of air end and load regulation control, etc. In general, an efficient screw compressor needs a rotor profile of which has a large flow cross-section area, short sealing lines and a small blow-hole. In this study, experimental study was performed with newly designed $5{\times}6$ rotor profile and various shapes of air end. Results show that the measured specific power consumption of the newly designed screw compressor appeared to be lower than any other published data for the equivalent screw compressors manufactured.