• Microbiology and Biotechnology Letters
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• v.20 no.5
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• pp.597-606
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• 1992

Effects of dilution rate, inlet glucose and ammonium chloride concentrations on ,he performance of continuous culture of Alcaligenes eutrQPhus for poly-p-hydroxybutyrate (PHB) production were investigated. When inlet substrate concentrations were maintained constant (inlet glucose concentration = 20 g/l, inlet ammonium chloride concentration = 2 g/l), growth rate of residual biomass and PHB production rate showed its maximum at $0.1h^{-1}$ and $0.06h^{-1}$, respectively, and washout at $0.13h^{-1}$. PHB content decreased from 50% to 25% by increasing dilution rate, while specific PHB production rate increased continuously. Cell mass and PHB concentration gave its maximum values at inlet ammonium chloride concentration of 2 g/l and thereafter decreased, which showed the existence of substrate inhibition by ammonium. When inlet glucose concentration was 30 g/l, cell mass reached its maximum value, while PHB concentration increased continuously. The parameters of kinetic model were evaluated by the graphical and parameter estimation methods. The computer simulation results for the effects of dilution rate, inlet glucose and ammonium chloride concentrations fitted the experimental data very well.

• The Journal of Korean Society for Radiation Therapy
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• v.33
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• pp.25-33
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• 2021

Purpose : The purpose of this study is to evaluate the accuracy and usefulness of the Trigger mode for the Respiratory Gated Radiation Therapy (RGRT) Materials and methods : A QUASAR respiratory phantom that inserted a 3 mm fiducial marker (a gold marker) was used to estimate the accuracy of the Trigger mode. And the 20 bpm was used as reference respiration rate in this study. The marker that placed at the center of the phantom was contoured, and the lower threshold of a gating window was fixed at 2.0 mm using an OBI with Truebeam STx^TM. The upper threshold was measured every 0.5 mm from 1.0 mm to 3.0 mm. The respiration rates were changed every 10 bpm from 10 bpm to 60 bpm. We repeatedly measured five times to check the error rate of the trigger mode in the same condition. Result : The differences of a distance from a peak phase to upper threshold, 1.0 to 3.0 mm at a 20 bpm as a reference for 3 days in a row were 0.68±0.05 mm, 0.91±0.03 mm, 1.23±0.03 mm, 1.42±0.04 mm, and 1.66±0.06 mm, respectively. Measurement result of changes in respiratory rate compared to baseline respiratory rate in maximum absolute difference. The coefficient of determination (R2) to estimate the correlation between the respiration velocity and variation of absolute difference was on average 0.838, 0.887, 0.770, 0.850, and 0.906. The p-values of all the variables were below 0.05. Conclusion : Using Trigger mode during respiratory gated radiation therapy (RGRT), accuracy and usefulness of trigger mode at reference breathing rate were confirmed. However, inaccuracies depending on the rate of breathing it could be uncertain in case of respiration rate is faster than 20 bpm as a standard respiration rate compared to slower than 20 bpm. Consequently, when conducting a RGRT using the trigger mode, real time monitoring is required with well educated respiration.

• Journal of Korean Society of Transportation
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• v.23 no.4 s.82
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• pp.17-28
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• 2005

About 91.1% of Railway-Highway Crossings (RHC) in Korea use a Constant Distance Warning System(CDWS), while about 8.9% use a Constant Warning Time System(CWTS). The CDWS does not recognize speed differences of approaching trains and provides only waiting times to vehicles and pedestrians based on the highest speed of approaching trains. Under the CDWS, therefore, low speed trains provide unnecessary waiting times at crossings which often generates complains to vehicle drivers and pedestrians and may cause wrong decisions to pass the crossings. The objective of this research is to improve the safety of the RHC by developing accurate a CWTS. In this research a train speed and location detection system was developed with ultra sonic detectors. Locations of the detectors was decided based on the highest speed and the minimum warning time of Saemaul of 160 km/h. To validate the algorithms of the newly developed systems the lab tests were conducted. The results show that the train detection system provides accurate locations of trains and the maximum error between real speeds of trains and those of the system was 0.07m/s.

• Annual Conference of KIPS
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• 2008.11a
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• pp.3-4
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• 2008

본 논문에서 k-means 군집화 알고리즘을 효율적으로 적용하는 방법을 제안했다. 제안하는 알고리즘의 특징을 속도 향상을 위해 예측 데이터를 이용한 것이다. 군집화 알고리즘의 각 단계에서 군집을 변경할 데이터만 최인접 군집을 계산함으로써 계산 시간을 줄일 수 있었다. 제안하는 알고리즘의 성능 비교를 위해서 KMHybrid 와 비교했다. 제안하는 알고리즘은 데이터의 차원이 큰 경우에 KMHybrid 보다 높은 속도 향상을 보였다.

• Proceedings of the KAIS Fall Conference
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• 2003.06a
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• pp.98-101
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• 2003

폴리머 수용액인 점탄성 유체속에서 물체를 떨어뜨리면 시간 간격에 따라 종말속도가 다르게 측정된다. 이는 폴리머 수용액이 점성과 탄성을 포함하고 있는 것으로 수용액 내부에서 처음 통과한 물체를 기억하는 기억유체(memory fluid)라고 정의 할 수도 있다. 낙하에 사용된 물체는 속이 빈 알루미늄 구를 사용하였으며 구 내부에 일정량의 철분을 삽입하여 밀도를 변화시켰다. 이 결과 구를 떨어뜨리는 시간 간격이 작을수록 종말속도 값은 크게 나타나며 시간 간격이 충분히 크면 처음 구를 떨어뜨릴 때의 종말속도와 같게 된다. 또한, 농도가 증가할수록 처음 구를 떨어뜨려 측정된 종말속도는 서서히 감소하다가 측정시간간격의 85％를 통과하며 다시 처음의 속도에 도달하게 된다. 구의 종말속도는 점탄성 유체의 농도가 각각 500wppm, 1000wppm, 2000wppm의 경우 처음 구를 떨어뜨린 후에 구의 밀도와 온도변화에 따라 최고속도에 도달하는 시간도 증가하였으며, 시간이 경과할수록 감소하여 일정시간이 경과한 후에는 처음의 상태로 복귀되는 것을 알 수 있다.

• Journal of Korea Water Resources Association
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• v.40 no.9
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• pp.723-734
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• 2007

This study was to investigate the settling velocity which is an important factor for the prediction of cohesive deposition under the various densities of particle and dissolved ion addition$(Na^+,\;Cl^-,\;OH^-,\;H^+)$ in rivers, ports, reservoirs and lakes. Settling velocity of suspended fine particles in still water was measured with a pressure sensor (maximum 10 mbar). At the initial concentration of 20g/l of alumina and quartz the average settling velocities were high due to the aggregation behaviour of particles. At this point it was 0.185 mm/s (alumina) and 0.022 mm/s (quartz). Above this initial concentration it was on the decrease owing to the hindered settling. The higher the salinity is, the faster the settling velocity of alumina and quartz is. Furthermore, in an acid condition the average settling velocity of alumina was on the decrease. In an alkaline water, which causes strong flocculation, the average settling velocity of alumina it was observed on the increase. However, in an alkaline medium the low average settling velocity of quartz powder was measured.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04b
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• pp.625-627
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• 2001

기존의 종이지도를 수치지도 처리과정으로 얻어진 등고선(contour line) 데이터는 원격탐사(Remote Sensing)와 지리정보시스템(GIS)의 응용분야에서 주로 사용되어지는 데이터이다. 이러한 등고선은 해당 지역의 DTM(Digital Terrain Model) 데이터 생성을 위해 보간(interpolation)하여 생성하는 데 연구가 집중되어 왔다. 본 논문에서는 DEM(Digital levation Model)으로부터 얻어진 등고선 데이터를 이용하여 사용자에게 3차원으로 가시화 해 줄 수 있는 기법을 소개한다. 등고선 추출을 위한 방법으로는 기존의 소개되어진 Marching Square 알고리즘을 적용하였고, 지역적인 최고점(local minimum)과 최소점(maximum)을 구하기 위해 등고선을 열린 등고선(open contour)과 닫힌 등고선(closed contour)으로 분류하게 된다. 지역적 최고, 최소점을 찾기 위한 탐색공간을 줄이기 위해 닫힌 등고선만을 닫힌 등고만을 대상으로 등고선 트리를 생성하였으며, 생성된 트리의 리프노드에 대해서 최고, 최소점에 대한 근사(approximation)를 수행하게 된다. 이렇게 구해진 근사된 장점들과 등고선 데이털 입력으로 하여 제한된 딜로니 삼각분할(Constrained Delaunay Triangulation)을 수행함으로써, 3차원 지형을 재구성할 수 있다. 실험에서 간단한 그리드 샘플데이터와 USGS로 획득한 데이터를 이용하여 속도 측정을 하였다. 결과적으로 저장공간 측면에서 적은 량의 데이터를 가지면서 등고선을 표현할 수 있는 3차원 지형을 랜더링할 수가 있음을 알 수 있다.

• Annual Conference of KIPS
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• 2001.10a
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• pp.641-644
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• 2001

기존의 종이지도를 수치지도 처리과정으로 얻어진 등고선(contour line) 데이터는 원격탐사(Remote Sensing)와 지리정보시스템(GIS)의 응용분야에서 주로 사용되어지는 데이터이다. 이러한 등고선은 해당 지역의 DTM(Digital Terrain Model) 데이터 생성을 위해 보간(interpolation)하여 생성하는 데 연구가 집중되어 왔다. 본 논문에서는 DEM(Digital Elevation Model)으로부터 얻어진 등고선 데이터를 이용하여 사용자에게 3 차원으로 가시화 해 줄 수 있는 기법을 소개한다. 등고선 추출을 위한 방법으로는 기존의 소개되어진 Marching Square 알고리즘을 적용하였고, 지역적인 최고점(local minimum)과 최소점(maximum)을 구하기 위해 등고선을 열린 등고선(open contour)과 닫힌 등고선(closed contour)으로 분류하게 된다. 지역적 최고, 최소점을 찾기 위한 탐색공간을 줄이기 위해 닫힌 등고선만을 대상으로 등고선 트리를 생성하였으며, 생성된 트리의 리프노드에 대해서 최고, 최소점에 대한 근사(approximation)를 수행하게 된다. 이렇게 구해진 근사된 정점들과 등고선 데이터를 입력으로 하여 제한된 딜로니 삼각분할(Constrained Delaunay Triangulation)을 수행함으로써, 3 차원 지형을 재구성할 수 있다. 실험에서 USGS 로부터 획득한 지형 데이터를 이용하여 속도 측정을 하였다. 결과적으로 저장공간 측면에서 적은 량의 데이터를 가지면서 등고선을 표현할 수 있는 3 차원 지형을 렌더링 할 수 있음을 알 수 있다.

• Journal of Animal Science and Technology
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• v.48 no.4
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• pp.487-492
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• 2006

This study estimated characteristics and genetic parameters for milking traits in Holstein dairy cattle. Daily records (12,561) were available from a hundred fifty four lactating cows with sixty six sires at National Livestock Research Institute from November, 2005 to April, 2006. The cows were fed same rations, and were milked twice daily using milking parlour equipped with Alpro-system?? to collect milking records automatically. The experimental cows have averaged 1.9 parities, 139.7 days in milk, and 13kg milk yield per milking. Average milk flow was 64% of peak milk flow. Milking duration, peak milk flow, average milk flow, and milk yield per milking were 5.57±1.67 minutes, 3.58±0.79kg/minute, 2.28±0.51kg/minute, and 13.02±4.09kg, respectively. All traits in the morning milking were higher than those of in the evening milking, and were also increased with parity. Heritabilities for milking duration, peak and average milk flow, and milk yield per time were 0.49, 0.70 0.58 and 0.36, respectively. The genetic correlations of milking duration with peak milk flow, average milk flow, and milk yield per time were 0.48, 0.54, and 0.41, respectively. The correlations of milk yield per milking with peak milk flow and average milk flow were 0.23 and 0.30, respectively. In conclusion, milk flow was increased with milk yield; however milk flow was opposite relationship with milk duration. Further studies are not only necessary to warranty genetic parameters, but pre-installation of automatic recording system to collect daily milking record is also necessary.

• (The)Study of the Eastern Classic
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• no.32
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• pp.363-390
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• 2008

In this article, the author studied the relationship between the Sovereign and the follower in Juyeok which contained some eliments, such as Eum-Yang, Soseong 8 gyae, Daeseong 64 gyae. In Juyeok, the 'Sovereign 5 hyo' (1) shows distinctiveness in basic characteristics whether they are Eum or Yang(high level classification), (2) shows characteristics of Soseong-gyae to which they belong(middle level classification), (3) shows different characteristics according to Daeseong-gyae's circumstances(low level classification). Five Yanghyo are regarded as male sovereign having masculinity, whereas five Eumhyo are female sovereign with femininity. Gungyae is the most 'sturdy type leader' who possesses dignity and has good judgement. Taegyae, the blessing type leader, holds affection and calmness within sturdiness. Rigyae is gorgeous and passionate 'enthusiastic type leader'. Jingyae, the pioneering leader, bravely starts ascending in Eum-dominant atmosphere. Songyae has the virtue of hesitancy and concession, known as the leader of humbleness. Gamgyae always stay low and calm, regarded as a leader of sense. Gangyae shoots up from the earth, meaning a leader of strong will. Gongyae, embracing type leader, is straight and square, though it tries to embrace everything. Daeseong-gyae(64gyae) is formed by Soseong-gyae piling another Soseong-gyae. The characteristics of Soseong 8gyae are embodied in two-level form, the top(inner gyae) and the bottom(outer gyae). Simultaneously, the whole characteristics of 대성괘 are embodied. The Sovereign should show his/her leadership based on the 'characteristics of Daeseong-gyae'. These characteristics are the contingency from 'contingency leadership'. In other words, they are preconditions which leaders ought to admit.