• 대한방사선기술학회지:방사선기술과학
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• 제42권6호
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• pp.477-482
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• 2019

Recently, due to the increased use of medical radiation, the radiation exposure of radiation workers should be considered as well as medical exposure of patients. And it is recommended to close the door during radiography. however, In this study, when the door was inevitably opened for radiography, the proposed method was to install the shield as a method of reducing the exposure dose. And its efficiency was analyzed. In simple chest radiography, the measurement point was changed according to the measurement location. Dose rate were measured 10 times for each condition using a dosimeter. And the average value was derived. Using this, the change of dose according to the opening and closing of the door and the installation of the shield was analyzed. Using this, we compared and analyzed the dose change according to the door opening and closing and the installation of the shield, and significance was verified through the SPSS ver. 24. Depending on whether the door was opened or closed, 11,215.35%, 159.0%, 101.9% increased in front of the door in the consol room, behind the wall and behind the lead glass. Depending on the installing of the shield, the 49.2%, 29.6%, 19.9%, 30.6% decrease in front of the door in the examination and consol room, behind the wall and lead glass. In addition, statistical analysis was showed that there were significant differences in both the results according to whether the door was opened or closed and shielding(p<.05). Close the door during radiography. However, when the door should be opened, it was confirmed that the dose rate were reduced by installing the shield. Therefore, to optimize radiation protection, it is recommended to install shields when opening the door.

• 한국자동차공학회논문집
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• 제17권1호
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• pp.182-189
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• 2009

The noise from the sunroof can be divided into the low frequency buffeting noise and the high frequency turbulence noise generated when a car runs at the high driving speed. The wind deflector suppresses the buffeting noise generation by accelerating the vortex shedding from the front edge of sunroof opening, and guides the flow direction so that air can pass smoothly over the sunroof opening. To reduce the buffeting noise and the high frequency noise, it is very important to locate a deflector in a proper position depending on the driving speed and the sunroof opening width. The deflector's sectional shape also plays an important role in efficiently reducing the buffeting and high frequency noise. In this paper, we determined the optimum deflector's sectional shape and examined the flow characteristics behind a sunroof deflector through CFD analysis with changing the deflector height, the driving speed and the sunroof opening width. It is found that the deflector needs to be located in the higher location to control the buffeting noise by shedding the higher frequency vortices to accelerating vortices from the sunroof front edge. The deflector may act as a new noise source at the high driving speed, then it is desirable to put the deflector at the proper height to reduce the flow fluctuations and the noise generation. We also made a road test to verify CFD analysis results in this study.

• 한국화재소방학회논문지
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• 제28권5호
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• pp.37-43
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• 2014

재실자가 부속실로의 피난 시 부속실 송풍기가 작동하기 전단계에서는 실내화재로 인한 풍속이 발생하여 부속실 개방과 더불어 연소생성물이 부속실을 오염시켜 피난장애의 결과를 가져올 수 있다. 이로인한 화재크기 및 실내 개구부 크기가 화재풍속에 미치는 영향을 확인하기 수치해석 연구를 수행하였다. 수치해석에서는 화재크기 및 실내 개구부 크기를 달리하였고, 실제의 공동주택 형상과 치수를 반영하였다. 수치해석 결과, 화재크기별 실내의 개구부 크기에 따라서 중성대 높이가 변화하여 부속실로 흐르는 화재풍속 특성이 다르게 나타남을 확인할 후 있었다. 또한, 실내 중성대가 높은 곳에 형성된 경우에는 방화문 상 하부에서 화재풍속의 차이가 나타남을 확인할 수 있었다.

• 지구물리
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• 제7권2호
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• pp.135-149
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• 2004

The present time is wanted quickness corretness position so as having more and more concern about present my position AS a doncing fan the intrenet marketed of fornation and recongnition about spatial generel is changed now is opening that present my position is where? to questing is answering through smaller (Mobile Device : Mobile Phone, PDA, GPS) then palm of the hand like this background, we know about that what is LBS?, service commercial of LBS SUCH embodiment practical use and possibilities of the future!!

• 한국유체기계학회 논문집
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• 제15권4호
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• pp.12-18
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• 2012

This study was performed to found out the deviations for clamp-on type ultrasonic flowmeter installed in downstream of valves. It was selected three types of two-path flowmeter mainly used for K-water as test. Experiment carried out to confirmed characteristics of deviation depending on the sensor location, straight pipe length and maker for 1-path, 2-path and 4-path combined 2-path flowmeter. It was selected two kinds of valves with 100 % and 50 % opening, butterfly valves and gate valves, for flow disturbance factor. Finally, we suggested number of sensors by maker, straight pipe length and installed location of sensors satisfying the tolerance depending on the experiment results.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2006년도 추계학술대회
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• pp.332-335
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• 2006

This paper considers a facility location problem, which is concerned with locating facilities on a supply chain network and installing the associated equipments at the facilities to meet a given set of demands. The objective function is to minimize the sum of setup cost (facility opening cost and equipment installation cost), operation cost, and distribution cost. For the equipments, various choices of equipment modes need to be determined. Moreover, in the problem, overwork is allowed each facility but at expensive operation cost. The proposed problem is characterized as being NP-hard problem, so that a heuristic algorithm is derived. In order to evaluate the performance of the proposed algorithm, computational experiments with various numerical instances are conducted.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2002년도 추계학술발표대회
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• pp.321-326
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• 2002

To design mechanical ventilation for bathroom of apartment houses where air supply and exhaust are taken Into consideration, mock-ups of ventilation systems, widely used in bathroom of apartment houses with an area of 100$m^2$, were made and installed in a laboratory, These ventilation mock-ups were available for control of air supply and exhaust, and the size of supply openings were 40cm$\times$1cm, 40cm$\times$3cm, 40cm$\times$5cm. They were installed at five positions, spaced 40cm at a height of 25cm from the floor. and the position of exhaust fans were four corners and center Exhaust fan established each one on corner of the ceiling and one in center. As result that measure ventilation effect by each condition, size of hole that supply air is big, and ventilation effect took effect to be good establishment location is low, Also, distance of exhaust fan is far with hole that supply air, ventilation effect took effect by superior thing.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권12호
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• pp.3166-3181
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• 2012

Localization of mobile station (MS) has now gained considerable attention. Since the hybrid measurements can help to improve the positioning accuracy, several hybrid localization methods have been proposed in the literature. However, the high performance estimator with the closed-form solution and complete performance analysis for time-of-arrival/signal strength (TOA/SS) localization technique is still an opening issue. Two TOA/SS localization algorithms with the closed-form solutions are proposed for the cases with or without uncertainty in the positions of base stations. Furthermore, performance analysis for the TOA/SS localization technique is presented. Both the theoretical variances and Cramer-Rao lower bounds (CRLBs) are derived and the relationship between the cases with or without uncertainty is given. The paper also proves that the TOA/SS scheme has a lower CRLB than the TOA (or SS) scheme. Theoretical analysis and simulations show that the proposed method can reach its CRLB.

• 건축역사연구
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• 제30권5호
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• pp.17-28
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• 2021

The Sijeon (Licensed Markets) legally permitted by the government along the Jongno and the Namdaemunro Avenues played a central commercial role in Hanyang. However, after the opening of the port in the late Joseon era, the Licensed Markets suffered a blow and declined due to the introduction of a new product of civilization and the appearance of foreign merchants. Although the Licensed Markets, which have been maintained without major changes for a long time, have played a major role in the urban spatial structure, the exact location has not been still determined, and researches until now has remained limited for such that. In this study, based on the 1912 land survey records, the location of the Licensed Markets pre-and post- 1910 is identified, and the spatial change of the dismantling process is investigated.

• Journal of Korean Neurosurgical Society
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• 제47권3호
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• pp.169-173
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• 2010

Objective : The normal anatomic relationships characteristic of the pituitary stalk area were previously thought to involve only one location. The purpose of this study was to re-evaluate the anatomic location of the pituitary stalk and possible varying locations in relation to the tuberculum sellae and dorsum sellae using morphometric evaluation and anatomic dissection of human cadaveric specimens. The surgical implications of the variations are discussed. Methods : The calvaria were removed via routine autopsy dissections, and the brains were removed from the skull while preserving the pituitary stalk. The diaphragma sellae, tuberculum sellae, and the location of the pituitary stalk were examined in 60 human cadaveric heads obtained from fresh adult cadavers. Empty sellae were excluded. Results : The openings of the diaphragma sellae averaged $6.62{\pm}1.606mm$ (range, 3-9 mm). The distance between the tuberculum sellae and the posterior part of the pituitary stalk was 1 to 8 mm. The upper face of the diaphragma sellae appeared flat in 26 (43%), concave in 24 (40%), and convex in 6 cases (10%), with a prominent tuberculum sellae in 4 cases (7%). The location of the chiasm was normal in 47 cases (78%), with a prefixed chiasm in 3 cases (5%) and a postfixed chiasm (17%) in the 10 cases. Four cadaver specimens had prominent tuberculum sellae and other parameters were not evaluated. Conclusion : When opening the chiasmatic cistern, neurosurgeons should be aware about the relationship between the pituitary stalk and the surrounding structures to prevent inadvertent injury to the pituitary stalk.