• Journal of Korea Water Resources Association
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• v.44 no.5
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• pp.377-388
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• 2011

Surface Image Velocimetry (SIV) is a recently-developed discharge measurement instrument. It uses image processing techniques to measure the water surface velocity and estimate water discharge with given cross section. The present study aims to implement a FSIV (Fixed-type Surface Image Velocimetry) at Soojeon Bridge in the Dalcheon. The hardware system consists of two digital cameras, a computer, and a pressure-type water stage gauge. The images taken with the hardware system are sent to a server computer via a wireless internet, and analyzed with a image processing software (SIV software). The estimated discharges were compared with the observed discharges through Goesan dam spillway and index velocity method using ADVM. The computed results showed a good agreement with the observed one, except for the night time. The results compared with discharges through Goesan dam spillway reached around 5~10% in the case of discharge over 30 m3/s, and the results compared with discharges through index velocity method using ADVM reached around 5% in the case of discharge over 200 $m^3/s$. Considering the low cost of the system and the visual inspection of the site situation with the images, the SIV would be fairly good way to measure water discharge in real time.

• Journal of Yeungnam Medical Science
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• v.23 no.1
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• pp.71-81
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• 2006

Background: This study was done to better understand patterns, trends and local distribution patterns of malocclusion so that we can provide adequate information to patients, to help make the appropriate diagnosis and therapeutic plans, and to assess the future directions of malocclusion treatment. Materials and Methods: Malocclusion patterns, distribution and trends of visiting patients were examined in 993 malocclusion patients who had been evaluated and diagnosed at the Department of Dentistry, Yeungnam University Hospital over a 10-year period from 1995 to 2004. Results: The number of visiting patients per year showed an increasing trend and the visit rate was 1.28 time-higher in females(56.1%) than in males(43.9%). 1) Age distribution showed that the 7-12 year-old group was the largest (36.7%). Geographic distribution showed the majority of patients were from the Dalseo district(28.2%). Angle's malocclusion classification revealed that class III was the largest(38.4%). Crowding was the chief complaint in the highest percentage of patients(33.9%). The therapeutic method used was the fixed appliance in 61% of cases and a combination with extraction in 30.8%. Conclusions: The availability of dental services can accommodate orthodontic needs adequately as well as obtain reliable quantitative information regarding the characteristics of orthodontic patients.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.5
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• pp.263-270
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• 2021

In this study, a reliability-based design optimization of a 130-m class fixed-type offshore platform, to be installed in the North Sea, was carried out, while considering environmental, material, and manufacturing uncertainties to enhance its structural safety and economic aspects. For the reliability analysis, and reliability-based design optimization of the structural integrity, unity check values (defined as the ratio between working and allowable stress, for axial, bending, and shear stresses), of the members of the offshore platform were considered as constraints. Weight of the supporting jacket structure was minimized to reduce the manufacturing cost of the offshore platform. Statistical characteristics of uncertainties were defined based on observed and measured data references. Reliability analysis and reliability-based design optimization of a jacket-type offshore structure were computationally burdensome due to the large number of members; therefore, we suggested a method for variable screening, based on the importance of their output responses, to reduce the dimension of the problem. Furthermore, a deterministic design optimization was carried out prior to the reliability-based design optimization, to improve overall computational efficiency. Finally, the optimal design obtained was compared with the conventional rule-based offshore platform design in terms of safety and cost.

• The Korean Journal of Nuclear Medicine Technology
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• v.23 no.1
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• pp.54-58
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• 2019

Purpose At now, there are many kind of dedicated heart SPECT machine in clinical nuclear medicine. Among those, the fixed focusing type SPECT can make a good quality, quantity image because a detectors of this SPECT arranged forward a special ROI and didn't rotate around of body. So, in this paper, we will evaluate a spatial uniformity about resolution and sensitivity at a same plane of a fixed focusing type SPECT. Materials and Methods We used D-SPECT as a fixed focusing type SPECT and Cario MD as a rotated parallel type SPECT to comparing each other. We injected $^{99m}Tc(14.8MBq/1cc)$ to 10 capillary tube (diameter=1mm), and we set those line sources a tfield of view of each SPECT. And then we acquired SPECT date, we applied are construction by recommended methods. By using two tomography images, we calculated a full width of half maximum as a resolution and total counts as a sensitivity, and we compared a CV (coefficientofvariation) values between two images as a spatial uniformity. Results In case of D-SPECT, a CV of resolution and sensitivity are 7.45%, 12.34%. In case of Cario MD, an CV of resolution and sensitivity are 12.49%, 21.84% Conclusion As a results, CV of resolution and sensitivity of a fixed focusing type SPECT is 67.75%, 77.00% higher than ones of a rotated parallel type SPECT. It means that a fixed focusing type SPECT is more uniformed, because this new SPECT can reduce a motion blur artifact by rotating detector around body, also all of detector that made by semiconductor arrange forward a special FOV like heart.

• Journal of Korean Port Research
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• v.10 no.2
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• pp.91-101
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• 1996

Today transportation problems are severer with the increase of the vehicles and travel demand in urban areas, but could not be completely solved with only the expansion of the new transportation facilities. Because the expansion of the new transportation facilities are limited in urban areas. As one of the Transportation System Management(TSM) techniques in this study, the simulation results of the existing signal systems which were operated based upon the peak time periods for increasing the efficiency on the pretimed signalized intersections(PSI) during the different time periods : the AM on-Peak, the AM off-Peak, the PM off-Peak, and the PM on-Peak, were as follows : i) There was no distinct difference in the total traffic volumes concentrated on the signalized intersections during the different time periods, but a considerably big difference in the directional traffic volumes for those time periods. ii) There were about 53% reduction of the average delay and 51% reduction of the fuel consumption when applying the different signal systems to the different time periods regardless of the CBD and Non-CBD. iii) There were about 36% increase of the average delay and 33% increase of the fuel consumption when applying the same signal systems during the peak time periods to the different time periods regardless of the CBD and Non-CBD. Based on the above results, it was concluded that constructing the different signal systems for the different time periods would be better than construction the same ones for those periods on the pretimed signalized intersections in urban areas.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.87.1-87.1
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• 2015

우리나라는 세계적으로 보기 드문 조류발전의 적지이며, 특히 진도 울돌목, 장죽수도, 맹골수도, 완도 횡간수도 등 서남해안에 조류에너지 여건이 좋은 상태이다. 조류발전시스템은 물속에 잠겨서 동작하는 형태이므로, 대형 고정 설비가 요구되어 높은 부대비용 발생과 이상유무 발생시 유지보수가 어려운 문제가 있다. 이를 위해 설비 및 설치비용을 줄이는 부유식 형태와 유지보수가 용이한 구조 설계를 적용한 실용적인 조류발전시스템 개발하며, 주요 적용처로 관심이 높아져 가는 에너지자립섬 적용을 목표로 섬내 전기 수요에 부합되는 15 kW급 조류발전을 공급하고자 하며, 이외 다양한 해양에너지를 활용한 에너지 자립화 방향을 제시하고자 한다.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.10a
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• pp.213-214
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• 2000

총 암모니아성 질소(TAN)은 고밀도 양식에서 한계요소로 작용하는 수질인자 중의 하나이다. 생물학적 처리법에 의한 암모니아의 제거는 순환여과식 양식 시스템의 설계에서 가장 중요한 부분이다. 효율적인 순환 여과식 양식 시스템을 위해서는 생물반응기의 질산화 속도식을 구하여 적정한 용량의 처리시스템을 설계하여야 한다. (중략)

• Journal of KSNVE
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• v.6 no.5
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• pp.587-594
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• 1996

The differential equation governing both the free vibrations and buckling loads of tapered beam-columns of regular polygon cross-section with constant volume were derived and solved numerically. The parabolic and sinusoidl tapers were chosen as the variable depth of cross-section for the tapered beam-column. In numerical examples, the clamped-clamped, hinged-clamped and hinged-hinged end constraints were considered. The variations of frequency parameters and first buckling load parameters with the non-dimensional system parameters are reported in figures, and typical vibrating mode shapes are presented. Also, the configurations of strongest columns were determined.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.3
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• pp.207-210
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• 1982

For the removal of initial water content in cuttlefish, the effects of fixed-bed drying condition on the drying rate were investigated, with following results. 1. The drying rate of cuttlefish dried at fixed-bed condition was also faster than that at natural convection type or hot air dryer.2. By controlling air temperature and its direction to cut-and-peeled sample the drying time can be reduced to 2 hrs. 3. Shirai's equation and Arrhenius' law were applicable to fixed-bed dried cuttlefish. Drying rate constant (k) by Shirai's equation, and Arrhenius' plot were as shown in Table 3, 4 and Fig.3, respectively.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.108-111
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• 2012

최근에 태풍 매미 등 이상 기후로 인한 기상이변이 빈번히 발생함에 따라 그에 대한 대처방안을 모색하기 위해 2005년 해양수산부에서는 지역 및 해역별 특성을 분석하여 종전 설계기준을 강화하였다. 하지만, 기존에 설계된 항만 구조물의 마루높이 및 피복재 중량 등이 새로 개정된 설계기준에 미치지 못하는 등 안전성에 대한 문제가 발생하고 있으며, 이러한 문제점을 개선하기 위해 기존 방파제를 보강하는 여러 방식이 제안되고 있다. 그 중 부유식방파제는 해수의 소통을 방해하지 않는 친환경적인 구조물로써, 연약지반에 시공이 가능하고 시공 시 오탁이 적게 발생하여 시공이 편하다는 장점을 가지고 있다. 또한 구조물의 해체 및 보강시 건설폐기물을 발생시키지 않는 친환경적인 구조물이기 때문에 새로운 방식의 대체 외곽항만구조물로 관심을 받고 있다. 이에, 본 연구에서는 사석경사제 전면에 부유식구조물을 설치하여 방파제 보강하는 방안을 제시하고자, 부유식구조물을 통과한 파랑이 사석경사제와 만나 발생하는 처오름높이를 분석하였다. 본 수치모의에서는 유체의 점성 및 난류특성을 포함하고 있는 Navier-Stokes 방정식을 그대로 해석하는 2차원 수치파동수조(CADMAS-SURF)를 이용하여 수치 모의을 수행하였다. 부유식구조물은 불투수성구조물로 수면에 고정시키는 방식을 적용하여 사석경사제의 전면에 설치하였으며, 고정된 부유식구조물의 흘수심을 변화시켜 사석경사제에서의 처오름높이를 산정하였다.