• Journal of KIISE:Computing Practices and Letters
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• v.8 no.1
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• pp.9-16
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• 2002

Join operation exert a great effect on the performance of system in temporal database as in the relational database. Especially, as for the temporal join, the optimization of interval partition decides the performance of query processing. In this paper, to improve the efficiency of parallel join query in temporal database. I proposed Minimum Interval Partition(MIP) scheme that time interval partitioning. The validity of this MIP algorithm that decides minimum breakpoint of the partition is proved by example scenario and I confirmed improved efficiency as compared with existing partition algorithm.

• The KIPS Transactions:PartD
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• v.9D no.4
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• pp.571-578
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• 2002

In temporal database, extended time dimension for history management brings about complexity of join operation and increased cost. To solve this problem, a method that joins the divided segment time data after partition the time range into fixed time interval is introduced. But existing methods can't solve the ambiguity problem of time border that caused by temporal granularity in the partition point. In this paper, We suggested Fuzzy Minimum Interval Partition (FMIP) method that introduced the possibility distribution of fuzzy theory considered uncertainty time interval border in the partition line.

• Journal of Bio-Environment Control
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• v.19 no.4
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• pp.234-239
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• 2010

The irrigation interval and time for the supply of nutrient and water to the plant is important in the aeroponic system. This study was conducted to investigate the effect of irrigation interval on the growth of Phalaenopsis hybrid seedlings in the aeroponic system. Young bare-root plants (four leaves, 16 g in fresh weight) were used for this experiment. The composition of nutrient solution was, in $me{\cdot}L^{-1}$, 9 N, 3 P, 4 K, 4 Ca and 2 Mg. The electrical conductivity (EC) and pH of nutrient solution used was $1.2\;dS{\cdot}m^{-1}$ and 5.8, respectively. Irrigation intervals were 10, 20, 30, 40, and 50 minute and each irrigation time was 10 minute. The total fresh and dry weight, the number of branched roots, and relative growth rate at the 20 and 30 min. was greater than 10, 40, 50 min. interval. Especially, the fresh weight of roots at 30 min. interval was the highest. Leaf length was the highest at 30 min. interval but there was no difference in leaf width. The amount of water consumed for a month was 0.71 L per plant and it was reduced with increasing irrigation interval. There was no difference in the amount of consumed mineral contents for 15 days except for potassium. Potassium absorbed was the highest at 30 min. irrigation interval. As a result, the optimum irrigation interval was 30 min for the production of Phalaenopsis hybrid seedlings in the aeroponic system.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11a
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• pp.527-530
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• 2002

본 논문에서는 하드웨어/소프트웨어 시스템의 파이프라인 실행을 지원하는 알고리즘을 제안한다. 파이프라인 실행을 지원하기 위해 시간제약과 면적제약조건을 만족하는 분한 결과를 찾는 기존의 방법은 하드웨어/소프트웨어 분할과 파이프라인 스케줄링을 독립적으로 실행하였으며 최소시간의 파이프라인 입력간격으로부터 최적의 분할 결과를 얻기 위해 점진적인 방법을 사용하기 때문에 많은 알고리즘 실행시간을 가진다. 본 논문에서는 분할 단계에서 스케줄링을 함께 고려하면서 최소 입력 간격을 갖는 파이프라인 실행을 지원하는 낮은 복잡도의 알고리즘을 제안한다. 이를 위해 최소입격간격에서의 파티션에 분포하는 노드와 종속성을 찾아서 하드웨어 구현과 프로세서에서의 분포 그래프를 생성하고, 상대적 스케줄 긴박도[8]를 구할 때는 노드 별 실행시간과 구현비용을 고려하며 분할 이후에 발생하는 통신 지연 시간을 힘 에 반영한다. 논문은 최소 입력 간격내에서 구성되는 파티션에 존재하는 노드의 파이프라인 스케줄과 시스템 제약시간을 만족하면서 구현비용을 저하시키기 위한 낮은 실행시간을 갖는 분한 알고리즘을 제안한다.

• Journal of Veterinary Clinics
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• v.30 no.6
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• pp.435-441
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• 2013

This retrospective study evaluated the effects of the interval from calving to first insemination (ICFI) and days open (DO) on the reproductive performance in dairy cows. In the first analysis, data from 705 cows were grouped based on the ICFI: short (30-60 days, n=217), medium (61-90 days, n=309), and long (91-150 days, n=179). The occurrence of endometritis was greater in the long group than in short and medium groups (p<0.05). The occurrence of ovarian cysts increased with increasing ICFI (p<0.05), while body condition score (BCS) during the 5 month postpartum period was lower with increasing ICFI (p<0.01). The hazard of pregnancy by 365 days in milk (DIM) was lower (hazard ratio [HR]=0.70, p<0.0001) in the long group, but higher (HR=1.41, p<0.0001) in the short group compared with the medium group. In the second analysis, data from 436 cows were grouped based on the DO: short (30-90 days, n=154), medium (91-180 days, n=183), and long (181-360 days, n=99). The occurrence of a retained placenta was greater in the long group than in the medium group (p < 0.05). Ovarian cysts occurred more frequently in medium and long groups than in the short group (p=0.08). BCS was lower in the short group compared with medium and long groups at month 1 postpartum (p<0.05). Milk yield (kg/day) was greater in the medium group compared with the short group at months 2 to 5 postpartum (p<0.05). The hazard of first insemination by 150 DIM was lower in the long group than in the short group (HR=0.73; p<0.02). The hazard of pregnancy by 365 DIM was lower (HR=0.64, p<0.0001) in the long group than in the medium group, while the hazard did not differ between short and medium groups (p>0.05). Moreover, the culling rate was greater in the long group than in the short group (p<0.05). In conclusion, a longer ICFI and DO resulted in reduced reproductive performance in dairy cows, which was attributable to an increase in postpartum diseases, a lower BCS and a greater milk yield.

• Journal of Korean Society of Transportation
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• v.22 no.6
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• pp.109-120
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• 2004

Since the late of 1990, there have been number of studies on the required number of probe vehicles and/or optimal aggregation interval sizes for travel time estimation and forecasting. However, in general one to five minutes are used as aggregation intervals for the travel time estimation intervals for the travel time estimation and/or forecasting of loop detector system without a reasonable validation. The objective of this study is to deveop models for identifying optimal aggregation interval sizes of loop detector data for travel time estimation and prediction. This study developed Cross Valiated Mean Square Error (CVMSE) model for the link and route travel time forecasting, The developed models were applied to the loop detector data of Kyeongbu expressway. It was found that the optimal aggregation sizes for the travel time estimation and forecasting are three to five minutes and ten to twenty minutes, respectively.

• Journal of Korean Society of Transportation
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• v.35 no.1
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• pp.63-78
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• 2017

The purpose of this study is to determine the optimal aggregation interval to increase the reliability when estimating representative value of individual vehicle travel time collected by DSRC equipment in interrupted traffic flow section in National Highway. For this, we use the bimodal asymmetric distribution data, which is the distribution of the most representative individual vehicle travel time collected in the interrupted traffic flow section, and estimate the MSE(Mean Square Error) according to the variation of the aggregation interval of individual vehicle travel time, and determine the optimal aggregation interval. The estimation equation for the MSE estimation utilizes the maximum estimation error equation of t-distribution that can be used in asymmetric distribution. For the analysis of optimal aggregation interval size, the aggregation interval size of individual vehicle travel time was only 3 minutes or more apart from the aggregation interval size of 1-2 minutes in which the collection of data was normally lost due to the signal stop in the interrupted traffic flow section. The aggregation interval that causes the missing part in the data collection causes another error in the missing data correction process and is excluded. As a result, the optimal aggregation interval for the minimum MSE was 3~5 minutes. Considering both the efficiency of the system operation and the improvement of the reliability of calculation of the travel time, it is effective to operate the basic aggregation interval as 5 minutes as usual and to reduce the aggregation interval to 3 minutes in case of congestion.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2010.09a
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• pp.363-368
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• 2010

본 논문은 레미콘 차량의 관제 및 관리, 레미콘 플랜트의 효율적 운영을 위해 시행되고 있는 레미콘차량 관제 시스템의 최적 좌표 전송 주기를 평가하고자 하였다. 이를 위해 실제적으로 레미콘차량 관제 시스템을 운영 중인 레미콘회사를 사례로 2010년 5월 한달 간 운행된 20대의 차량에 30초, 1분, 3분, 5분 간격으로 수신 된 좌표 주기별 거리와 실제로 운행 된 거리를 비교하였다. 또한 최적 좌표전송주기를 평가하기 위해 30초, 1분, 3분, 5분 간격으로 전송되는 주기별 Packet 계산표에 따라 데이터 요금제를 비교 환산하여 비용 대비 최적의 좌표전송주기를 평가 하였다. 그 결과 1분 간격의 송신주기가 오차율이 2.34%, 1일 8시간 운행기준 월 송신요금이 10,000원으로 나타나 가장 합리적으로 분석되었다. 그러나 좌표전송에서 비정상적인 값이 수신 될 경우 그에 대한 방안이내 처리 절차 등의 추가적인 연구의 필요성이 제기된다.

• Membrane Journal
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• v.29 no.5
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• pp.292-298
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• 2019

The purpose of this study was to improve the desalination performance by using split electrodes in the capacitive desalination process. The experiment was carried out by measuring the desalination efficiency of the NaCl aqueous solution according to the partitioning of the electrode at 20 mL/min flow rate, 1.2 V, 3 min adsorption conditions, and -1 V, 1 min desorption conditions. The desalination efficiency for the non-divided electrodes with a surface area of $146cm^2$ reached 40% while the divided electrode with a surface area of $133cm^2$ showed a desalination efficiency of 57%. The desalination efficiency of the same split electrode was 49% at 2 cm divided interval and 57% at 1cm divided interval. The desalination efficiency of the split electrode was higher than that of the normal CDI and narrower divided intervals increased the performance.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.1127-1131
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• 2004

최근에 재해영향평가 등에서 많이 채택하고 있는 Huff의 4분위법에 의한 강우의 시간분포를 통한 유출량 산정은 도시화지역 등에서 유출량에 내한 관측기록이 없어서 적절한 검정이 불가능한 실정이다. 따라서 산정된 계획홍수량에 의해 설계되는 수공구조물의 경제성 또는 안전성의 정도를 파악하지 못하고 실무에 반영되는 문제를 내포하고 있다. 본 연구에서는 서울지역 최근 29개년간의 년 최대 강우관측자료에 대하여 각각을 Huff의 4분위법에 의한 10분 간격으로 시간분포고, 실제 관측 강우의 경우 10분 간격으로 판독하여 도시유출모형인 SWMM을 이용하여 유출량을 산정하고 결과를 비교하였다. 또한 각각에 대하여 유출량을 빈도해석하여 비교한 결과 강우의 시간분포간격이 짧은 경우 국내적용 Huff분포는 실강우분포에 의한 유출량보다 크게 산정되는 것으로 나타났다.