• 한국산학기술학회논문지
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• 제19권1호
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• pp.644-653
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• 2018

최근 기후변화로 인한 집중호우, 태풍 등의 영향으로 산사태가 빈번히 발생하고 있다. 산사태를 예방할 수 있는 효율적인 방법은 사방사업이다. 이러한 사방사업의 효율성을 높이기 위해서는 산지에서 유출되는 토사량에 대한 정량적 측정이 필요하다. 본 연구에서는 산지계류에 Load-cell 센서를 설치하고, 분동테스트를 통하여 계류에서의 적용성과 재하 형태에 따른 출력값을 비교하였다. 개별 및 복합 하중시험을 실시한 결과, Site 1에서 평균 0.4kgf, Site 2에서 평균 0.6kgf 차이로 재하 형태의 영향은 낮게 나타났다. 또한 측정값의 정확도를 높이기 위해 하중계수를 산정하였다. 하중계수를 Load-cell 측정 값에 적용하여 보정한 결과, 두 사이트에서 출력율이 각각 14.8%p, 24.6%p 상승하여 기준값에 근사하게 산정되었다. Load-cell 센서는 수위, 강우 등과 함께 시계열 분석을 통하여 산지 토사유출량을 정량적으로 산정할 수 있었다. 모니터링이 장기간 이루어진다면 산림유역에 대한 토사유출 매커니즘 구명에도 활용할 수 있을 것이다. 또한 Load-cell과 같은 센서를 산지 계곡에 적용함으로써 계측센서 등 관련분야 산업 발전에 기여할 수 있을 것으로 기대된다.

• 한국지리정보학회지
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• 제15권3호
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• pp.103-118
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• 2012

분포형 모형은 유역내에서 공간 분포된 임의 지점의 유출해석 결과를 손쉽게 얻을 수 있다. 이때 다양한 특성을 가지는 소유역으로 구성된 유역의 경우, 소유역에 대해 신뢰성 있는 유출량을 얻기 위해서는 소유역별로 보정된 모형을 적용해야 한다. 본 연구에서는 관측 유량자료가 있는 소유역별로 모형을 보정할 수 있는 다지점 보정 기술을 개발하였다. 이를 위해서 다지점 보정 대상매개변수의 선정 및 적용 방법과 소유역 네트워크 정보를 설정하는 방법을 제시하였다. 또한 다지점 보정 모듈을 구현하기 위한 클래스를 설계하고 GUI를 개발하였으며, 소유역별로 설정된 매개 변수를 이용한 유출해석 절차를 정립하였다. 다지점 보정 모듈을 낙동강 수계 선산 유역($977km^2$)에 적용하였다. 적용결과 다지점 보정 모듈은 유역내 소유역에 대한 모형의 보정에 효과적으로 적용할 수 있었으며, 다지점 보정에 의해서 소유역의 유출해석 결과를 향상시킬 수 있었다.

• International Journal of Concrete Structures and Materials
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• 제8권4호
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• pp.279-287
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• 2014

This paper presents the findings of an investigation of the fiber content variations in concrete being discharged from a ready-mix truck at the construction site. Concrete samples were extracted from the truck drums at the beginning, middle and end of discharge. Subsequently, fibers in each sample were separated from the concrete, and weighed. Presumably, synthetic macro fibers will float towards the top, i.e. towards the drum opening, of the inclined, revolving truck-drum, while, on the other hand, steel fibers will tend to gravitate towards the lower parts of the mixer drum. Accordingly, the discharge batch, containing synthetic macro fibers, will contain a higher amount of synthetic fibers per unit volume at the start of discharge than the average unit volume fiber content of the mix, and the content will gradually decrease further down the batch. The discharge batch of steel fiber concrete will contain fewer fibers per unit volume at the start of discharge than the average unit volume fiber content of the mix, and the content should gradually increase further down the batch. The correctness of the foregoing is partly confirmed. A certain percentage of the truck loads did not comply with the proposed requirements, mainly steel fiber reinforced batches, indicating the necessity of a code or guideline amendment. A change in the Norwegian shotcrete directive was made in 2011, based upon experimental research work (2010), which, in combination with the subsequent University of Life Sciences report (2012), constitutes the foundation of this article.

• 조명전기설비학회논문지
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• 제20권6호
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• pp.75-80
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• 2006

산업현장에서 많이 사용되고 있는 전력기기에 결함이 발생하면 치명적인 사고로 진전되어 경제적, 인적 손실이 발생될 수가 있다. 본 논문은 GIS에 사용되는 절연가스인 $SF_6$의 압력 변화에 따른 부분방전을 모의하고, 발생되는 부분방전 신호를 절연 진단 방법 중 하나인 UHF법을 이용하여 부분방전 시 방사되는 방사전자파의 스펙트럼을 분석해 금속 이물질이 $SF_6$가스 부분방전에 미치는 영향을 측정하였다. 이러한 연구는 현장 GIS 및 $SF_6$가스절연 전력설비에서 내부압력 변화 시 금속 이물질에 의해 발생되는 절연파괴 사고의 방지에 중요한 역할을 할 것으로 사료된다.

• 한국임상수의학회지
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• 제38권3호
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• pp.152-158
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• 2021

A 3-year-old spayed female beagle dog was presented with epiphora, severe hemorrhagic and purulent ocular discharge in the right eye (OD). A reflux of the discharge through the other canaliculi, associated with signs of chronic inflammation, was observed on cytology. Dacryocystorhinography revealed retention of contrast media ventral to the lower punctum, indicating complete obstruction and the potential presence of radiolucent foreign body. Ocular discharge subsided after the first treatment, including flushing of the nasolacrimal duct and application of topical antibiotics and corticosteroids, but clinical symptoms of the dacryocystitis waxed and waned thereafter. Surgical treatment was delayed for 8 months due to Dirofilaria immitis infection, and topical treatment and monthly flushing were maintained. On the day of operation, a foreign body was released through the fistula, while flushing for disinfection under general anesthesia, just before the surgery. Dacryocystectomy was performed to remove necrotic tissue and residual foreign body around the nasolacrimal cyst. Upon histopathologic findings, the removed foreign body was considered to be a plant, and the nasolacrimal cyst was comprised of chronic active ulcerative inflammation and necrotic tissues. At the 1-week recheck, improvement of epiphora and ocular discharge and healing of the surgical site was noted. In conclusion, nasolacrimal duct foreign body can be considered in recurrent dacryocystitis, despite nasolacrimal flushing and topical medication. In this study, dacryocystectomy was curative without recurrence of dacryocystitis or epiphora.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 C
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• pp.1930-1932
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• 2004

SOM(Self Organizing Map) algorithm which has some advantages such as data accumulation ability and the degradation trend trace ability was compared with conventionally used BP(Back Propagation) algorithm. For the purpose, partial discharge data were acquired and analysed from the artificial defects in GIS. As a result, basically the pattern recognition rate of BP algorithm was found out to be better than that of SOM algorithm. However, SOM algorithm showed a great on-site-applicability such as ability of suggesting new-pattern-possibility. Therefore, through increasing pattern recognition rate it is possible to apply SOM algorithm to partial discharge analysis. Also, for the image processing method it is required the normalization of the PRPDA graph. However, due to the normalization both BP and SOM algorithm have shown worse results, so that it is required further study to solve the problem.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 지반공학 공동 학술발표회
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• pp.174-187
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• 2005

Recently, because of environment, cost, supply and demand factors, though applying sea-sand as horizontal drains is getting difficult that usage of Gravel has been growing in large size of construction sites, Study on engineering properties and behavior characteristics of Gravel stratum is not thoroughgoing enough. We have applied Gravel Mat as the horizontal drains in O O construction site. We also conducted several field tests such as Material property test, Geosynthetics damage test with Repeated load, Discharge capacity test performed by inflow of upper soil and In-situ PBD Penetration test to review the application of Gravel Mat. Test results show that Gravel Mat is not only advantageous in Trafficability and Water drainage by Consolidation due to its great Internal friction angle and Permeability, but also easy to penetrate with Mandrel and has great discharge capacity and guarantee of the stability against geosynthetics damage at the same time. With these benefits Gravel Mat shows great application in fields.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.240-242
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• 2005

It is well known that the PD (Partial Discharge) signals are generated if insulators have some defects such as voids in electrical facility and various PD detection methods are developed for preventing electrical troubles. So, an interest for the PD signals is higher and higher according to the high concern for the defects detection method of the aging electrical facility. When the equipment to detect PD signals installed at site and it works, a lot of noises flow in the equipment from surrounding situation and it will be mixed with original PD waveform. So we can not get the desired PD waveform. Therefore, there are many trial to reject or suppress the noise from the PD signals from long times ago. The greater of them used the hardware such as bridge circuits and frequency filters to suppress the noise. This paper proposed a novel noise rejection method in acquired data from PD detection equipment. The noise has the irregular phase and higher signal level than real PD, and noise decision is performed after inspection of pulse distribution in ${\Phi}$-q-n graph of acquired data from PD detection equipments. By experimental results on high voltage electric equipments, it is shown that proposed method has good performance. It is expected that this noise rejection technology is useful in numeric calculation and trend management of PD level.

• 한국임상수의학회지
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• 제14권1호
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• pp.93-98
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• 1997

The vaginal endoscopy was performed in two Labrador Retrievers from onset of vaginal bleeding until metestrus accompanying with vaginal smear and blood progesterone concentration to investigate estral changes, and the intrauterine infusion of radiopaque fluid using vaginal endoscope (rigid 25-degree endoscope, Karl Storz) was detected by radiogrphy to determine if theis technique is feasible for future artificial insemination in the dogs. During the proestrus vaginal mucous membrane folds were edematous and a large amount of clear red discharge was present. In the beginning of estrus, the mucous membrane folds was present and the amount of the red discharge was decreased. In the estrus there were obbvious shrinkage, angulation of the membrane folds and decreasing of the discharge. In metestrus the vaginal folds started to round out and the surface appeared moist and sticky. The endoscope used for endoscopic monitoring of the vaginal mucosa was advanced until the external os of the cervix could be visualized. A plastic catheter, 8Fr guage was manupulated into the cervical os and then advanced through into the uterus. The radiopaque fluid was injected into the uterus through the catheter and radiographs taken to detect the site of insemination using the endoscopic technique revealed the exact infusion of the fluid in the uterus, consequentlyto prove that this technique is usable for more successful artificial insemintion tn the bitch.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.382-384
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• 1997

On-site partial discharge test by use of AC voltage has been considered not to be appropriate for the extruded power cable due to their large capacitance depending on their lengths. Therefore, it is proposed, in this work, to use switching impulse voltage of which the front time is set from 1ms to 10ms. This newly proposed method enables us to simulate the 1/4 period of power frequency at 60 Hz and to obtain similar effect of AC voltage test. Our tentative results show that 51 voltage is proved to be an alternative method, replacing AC voltage, by which partial discharge was well produced from the artificial defects integrated in 22.9kV distribution power cables.