• Korean Journal of Agricultural and Forest Meteorology
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• v.6 no.3
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• pp.170-176
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• 2004

This study was carried out to establish a spatial decision support system for evaluating climatic aspects of a given geographic location in complex terrains with respect to the quality apple production. Monthly climate data from S6 synoptic stations across South Korea were collected for 1971-2000. A digital elevation model (DEM) with a 10-m cell spacing was used to spatially interpolate daily maximum and minimum temperatures based on relevant topoclimatological models applied to Jangsoo county in Korea. For daily minimum temperature, a spatial interpolation scheme accommodating the potential influences of cold air accumulation and the temperature inversion was used. For daily maximum temperature estimation, a spatial interpolation model loaded with the overheating index was used. Freezing risk in January was estimated under the recurrence intervals of 30 years. Frost risk at bud-burst and blossom was also estimated. Fruit quality was evaluated for soluble solids, anthocyanin content, Hunter L and A values, and LID ratio, which were expressed as empirical functions of temperature based on long-term field observations. AU themes were prepared as ArcGlS Grids with a 10-m cell spacing. Analysis showed that 11 percent of the whole land area of Jangsoo county might be suitable for quality 'Fuji' apple production. A computer program (MAPLE) was written to help utilize the results in decision-making for site-selection of new orchards in this region.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.10
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• pp.82-90
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• 2011

Because of the development of Smart phone devices, the demands of high performance FPU(Floating-point Unit) becomes increasing. Therefore, we propose the high-speed single-/double-precision FPU design that includes an elementary add/sub unit and improved multiplier and compare and convert units. The most commonly used add/sub unit is optimized by the parallel rounding unit. The matrix operation is used in complex calculation something like a graphic calculation. We designed the Multiply-Add Fused(MAF) instead of multiplier to calculate the matrix more quickly. The branch instruction that is decided by the compare operation is very frequently used in various programs. We bypassed the result of the compare operation before all the pipeline processes ended to decrease the total execution time. And we included additional convert operations that are added in IEEE754-2008 standard. To verify our RTL designs, we chose four hundred thousand test vectors by weighted random method and simulated each unit. The FPU that was synthesized by Samsung's 45-nm low-power process satisfied the 600-MHz operation frequency. And we confirm a reduction in area by comparing the improved FPU with the existing FPU.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.4
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• pp.304-308
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• 2014

Accurate prediction of peak bloom dates (PBD) of flowering cherry trees is critical for organizing local cherry festivals and other associated cultural and economic activities. A two-step phenology model is commonly used for predicting flowering time depending on local temperatures as a result of two consecutive steps followed by chill and heat accumulations. However, an extensive computation requirement for parameter estimation has been a limitation for its practical use. We propose a sequential parameterization method by exploiting previously unused records of development stages. With an extra constraint formed by heat accumulation between two intervening stages, each parameter can then be solved sequentially in much shorter time than the brute-force method. The result was found to be almost identical to the previous solution known for cherry trees (Prunus ${\times}$ yedoensis) in the Tidal Basin, Washington D.C.

• The Transactions of the Korea Information Processing Society
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• v.3 no.4
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• pp.992-1001
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• 1996

Radix sort scans the data twice in a pass, to search bit 0s of the items being sorted and store them into the lowest address, and to search bit 1s and st ore them into the following addresses. This doubles the sorting time. In this paper, we introduce Reverse Radix Sort Algorithm, in which the data being sorted are sacnned just once and write upward from the lowest address if it is 0 and downward from the highest address if it is 1. The algorithm is simple and the hardware sorter implemented by this method shows very high sorting sped. Hardware implementation requires two separate pocket memories, register, an upward increasing address counter, a downward decreasing address counter, and comparator. The software simulation of Reverse Radix Sor Algorithm performs sorting in the speed of 54.9ms per 10 thousand of 8 bit digit data, but the hardware sorter spends 5.3ms to sort the same number of data.

• Horticultural Science & Technology
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• v.19 no.4
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• pp.540-544
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• 2001

The effect of long day treatment on the growth and flower bud differentiation of persimmon tree grown in a heated plastic house was investigated. The rate of leaf sprout was 65% in the long day treatment and 71% in natural day (control). In the long day, the shoot grew 16.7 cm longer, full bloom and harvest days were shorter, fruit weight was 16% lighter, and the sweetness and firmness of fruit were lower. The photosynthesis rate in the long day treatment was higher, showing the tendency of increasing with time. However, the rate of photosynthesis increased after 1600 hours showed higher than the control. Carbohydrate accumulation in the shoot was decreased, with higher nitrogen content and lower C/N ratio in the long day. The number of flower primordia per bud was less, and the days for differentiation was longer in the long day.

• Journal of Conservation Science
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• v.9 no.1
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• pp.48-52
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• 2000

A hundred wooden foundation piles were found underground during reconstruction for Heungreamun after removing ex-Chosunchongdokbu (ex-Government General of Chosun) building, which was built in 1916, at Kyungbok Palace in Seoul. It is known that larch piles had been collected from the Yaru area near Mt. Baekdu (Changbai). in North Korea. We examined 15 piles for identification of the species and their tree-ring structure. The species is identified as Larix gmelini by microscopic observation. Average diameter of the piles was 27 cm and average age 103 years. We obtained 151 year tree-ring chronology. However, we could not date the exact cutting years because there was no reference chronology yet. When we can obtain chronologies from living trees near the Yaru area, we could make a absolute and longer chronology for studying past history and environments around Mt. Baekdu.

• Korean Journal of Animal Reproduction
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• v.20 no.4
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• pp.385-393
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• 1997

다세포 생물에서 몸의 효율적 생존을 위한 각 기관의 homeostasis는 세포 증식과 사망에 의해 조절된다. 따라서, apoptosis라 명명된 세포사망은 정교한 기전에 의한 능동적이고 자발적인 사망기전으로써 몸의 정상적 유지를 위한 필수적인 현상이다. 발생기 세포나 신경세포 또는 흉선세포 분화 동안 과다한 세포의 제거가 apoptosis의 대표적인 예이며, 각종 호르몬에 의해 그 기능이 조절되는 난소세포에서도 apoptosis가 활발히 일어난다. Rat난소에는 태어날 때 수십 만개의 난포를 지니고 있는데, 이 중 단지 1%만이 배란에 사용되어질 뿐이고 나머지는 모두 사망하게 된다. 이러한 난포사망은 난소의 적절한 세포 수를 유지하기 위한 필수적 과정이며, 인위적으로 apoptosis를 억제하는 유전자인 bcl-2를 과다 발현시키면 난소암이 발생하는 연구결과가 이를 입증해주고 있다. 이처럼 중요한 난포 사망기전은 apoptosis라는 개념이 정립되면서 최근 들어 점차 그 연구가 활발해지고 있다. Apoptosis의 특징 중 뚜렷한 점은 DNA가 일정한 간격으로(180∼200 bp)잘려지는 DNA fragmentation현상으로, 이를 이용하여 DNA3'-end 부위에 방사선동위원소를 label한 후 이를 전기영동으로 분리하면 apoptosis를 손쉽게 측정할 수 있다. 난소의 기능은 시상하부호르몬인 LH와 FSH 뿐만 아니라 난소에서 분비되는 각종 난소국부호르몬들에 의해 조절된다. 특정한 발육단계의 난포는 특정한 호르몬에 의해 그 기능을 조절 받는데, 이러한 난소기능 조절기작은 매우 복잡한 경로를 지니고 있다. 이러한 복잡한 기작으로 인해 초기 연구에서첨 생체 내에서 밝히려는 연구 시도는 어려움에 부딪치게 되었다. 생체내 실험은 난소가 다양한 발육단계의 난포를 동시에 지니고 있어 특정한 발육단계의 난포 사망기전을 연구하기 어렵다. 또한 난포는 생체 내에서 다양한 호르몬을 동시에 분비하기 때문에 특정한 난소국부호르몬이 사망기전에 미치는 영향을 조사하기 힘든 점이 있다. 최근 들어 난포체외배양이 다양하게 개발되면서, 이러한 어려운 점을 극복할 수 있게 되었다. 본 논문은 각 발육단계의 난포를 절단해 체외배양하면서, apoptosis DNA 절단 현상을 이용하여 각종 난소국부 호르몬들이 난포발육단계별로 사망기전에 미치는 영향을 요약해 보였다. 난포는 발육하면서 점차 복잡한 호르몬 경로를 생존을 위해 필요로 한다. Prevulatory난포생존에 필요한 난소국부호르몬들은 early antral 단계의 난포에서는 그 미치는 영향이 감소되다가 preantral단계의 난포에서는 영향을 전혀 미치지 못했다. 단지 예외는 cGMP처리로써, 세포내 cGMP수준을 일정하게 유지시켜주는 것이 난포발육단계에 무관하게 생존에 중요한 인자로, 장래 연구는 난포 세포내의 cGMP수준을 조절하는 기작을 규명하는데 있을 것이다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.2
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• pp.303-310
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• 2018

Bitcoin (BTC) is a cryptocurrency proposed by Satoshi Nakamoto in 2009. Bitcoin makes its transactions with no central authorities. This decentralization is accomplished with its mining, which is an operation that makes people compete to solve math puzzles to include new transactions into block, and eventually block chains (ledger) of bitcoin. Because miners need to solve a complex puzzles, they need a lot of computing resources. In return for miners' resources, bitcoin network gives newly minted bitcoins as a reward to miners when they succeed in mining. To prevent inflation, the reward is halved every 4 years. For example, in 2009 block reward was 50 BTC, but today, the block reward is 12.5 BTC. On the other hands, exchange rate for bitcoin and Korean Won (KRW) changed drastically from 924,000 KRW/BTC (January 12th, 2017) to 16,103,306 KRW/BTC (December 10th, 2017), which made mining more attractive. However, there are no rigorous researches on the profitability of bitcoin mining. In this paper, we evaluate the profitability of bitcoin mining.

• Journal of KIISE:Databases
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• v.34 no.1
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• pp.46-58
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• 2007

Since microarray data acquire tens of thousands of gene expression values simultaneously, they could be very useful in identifying the phenotypes of diseases. However, the results of analyzing several microarray datasets which were independently carried out with the same biological objectives, could turn out to be different. One of the main reasons is attributable to the limited number of samples involved in one microarry experiment. In order to increase the classification accuracy, it is desirable to augment the sample size by integrating and maximizing the use of independently-conducted microarray datasets. In this paper, we propose a novel two-stage approach which firstly integrates individual microarray datasets to overcome the problem caused by limited number of samples, and identifies informative genes, secondly builds a classifier using only the informative genes. The classifier from large samples by integrating independent microarray datasets achieves high accuracy up to 24.19% increase as against other comparison methods, sensitivity, and specificity on independent test sample dataset.

• Horticultural Science & Technology
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• v.19 no.3
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• pp.348-351
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• 2001

'Saenara' released by National Horticultural Research Institute in 1997 is a mid-season apple cultivar with attractive red skin, high quality and high productivity. This cultivar originated from the cross between 'Spur EarliBlaze' and 'Spur Golden Delicious' at Suwon in 1981. It was first selected in 1992 and named 'Wonkyo Ga-08'. The regional adaptability test was carried out for 5 years from 1993 to 1997 at 7 different sites. 'Saenara' is medium in tree vigor and has a spreading tree form. It bears abundant flower buds on many spurs. It blossoms a day earlier than 'Spur Golden Delicious', 3 days later than 'Spur EarliBlaze'. Harvesting time of 'Saenara' is September 10, 140 days after full bloom at Suwon. Fruit shape is conical and skin color is bright red. Fruit weighs about 300 g and has $14.6^{\circ}Brix$ soluble solids content. It is susceptible to alternaria leaf spot (Alternaria mali Roberts).