• 제목/요약/키워드: initial seed

검색결과 266건 처리시간 0.026초

On the Initial Seed of the Random Number Generators

  • Kim, Tae-Soo;Lee, Young-Hae
    • 한국시뮬레이션학회:학술대회논문집
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    • 한국시뮬레이션학회 2001년도 The Seoul International Simulation Conference
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    • pp.464-467
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    • 2001
  • A good arithmetic random number generator should possess full period, uniformity and independence, etc. To obtain the excellent random number generator, many researchers have found good parameters. Also an initial seed is the important factor in random number generator. But, there is no theoretical guideline for using the initial seeds. Therefore, random number generator is usually used with the arbitrary initial seed. Through the empirical tests, we show that the choice of the initial values for the seed is important to generate good random numbers.

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ON THE INITIAL SEED OF THE RANDOM NUMBER GENERATORS

  • Kim, Tae-Soo;Yang, Young-Kyun
    • Korean Journal of Mathematics
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    • 제14권1호
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    • pp.85-93
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    • 2006
  • A good arithmetic random number generator should possess full period, uniformity and independence, etc. To obtain the excellent random number generator, many researchers have found good parameters. Also an initial seed is the important factor in random number generator. But, there is no theoretical guideline for using the initial seeds. Therefore, random number generator is usually used with the arbitrary initial seed. Through the empirical tests, we show that the choice of the initial values for the seed is important to generate good random numbers.

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Characterization of Grape Seed Oil

  • Kang, Han-Chul;Park, Won-Jong;Kim, Si-Dong;Park, Jong-Cheon
    • Applied Biological Chemistry
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    • 제41권8호
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    • pp.578-582
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    • 1998
  • Grape seed oil was characterized to assess the usefulness in the food industry. Among the various oils, the initial antioxidant activity was the highest for grape seed oil. Heating the oil at $180^{\sim}C$ for 20 min retained 86% of the initial activity. Grape seed and sesame oils showed a low peroxide value, about 2, implying a less oxidative reaction. The oxidation of grape seed oil was increased to a less extent by heat-treatment than other oils. Light exposure for 1 month resulted in a slight decrease in the antioxidant activity of grape seed oil, maintaining 96% of the initial activity. Other oils were all light-susceptible and the activities decreased significantly. The peroxide values of all the oils increased by light exposure, but the extent of oxidation was still the least for grape seed oil. The addition of grape seed oil to perilla oil was very effective, in that the peroxide value was 5-times decreased by 1 : 5 composition of grape seed oil versus perilla oil. These results indicate that grape seed oil can be used as a good cooking oil or an additive for other oils.

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김치 발효중 겨자의 첨가효과 (The Additive Effects of Mustard Seed(Brassica juncea) during Fermentation of Kimchi)

  • 서권일;정용진;심기환
    • 한국식품저장유통학회지
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    • 제3권1호
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    • pp.33-38
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    • 1996
  • To investigate the food preservative effects of mustard seed(Brassica juncea), mustard seed were added to Kimchi. Titratable acidity of Kimchi treated with mustard seed was higher than that of non-treated control at initial stage, but it was lower than control after 2 days of fermantation. The number of bacteria and lactic acid bacteria increased rapidly at the initial stage of fermentation and reached plateau by 2 days of fermentation. The number of bacteria and lactic acid bacteria of Kimchi treated with mustard seed was lower than that of control, and the more mustard seed added the less bacteria and lactic acid bacteria were observed.

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미세구조 조절에 의한 고투자율 Mn-Zn Ferrite의 특성제어 (Control of Electromagnetic Properties of High Initial Permeability Mn-Zn Ferrite with the Microstructure Control)

  • 도세욱;류지태;김정희;강태현;허원도
    • 자원리싸이클링
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    • 제7권4호
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    • pp.50-54
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    • 1998
  • 원하는 전자기적 특성인 높은 초투자율과 우수한 주파수 의존특성을 얻기 위해 Mn-Zn 페라이트계에서 핵입자의 첨가효과를 실험하였다. 소결온도에서 가소된 핵입자를 첨가함에 따라 비정상 입자성장이 말끔히 사라졌지만, 페라이트의 소결밀도와 초투자율이 감소하였다. 이와 반대로 매트릭스 입자의 가소온도보다 낮은 온도에서 가소된 핵입자의 첨가시에는 비정상 입자성장이 잔유하였으나, 적정한 핵입자 첨가로 Cutoff Frequency가 변화하지 않는 가운데 10∼20%의 초투자율값의 상승이 있었다.

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난각을 이용한 폐수중의 인 제거에 관한 연구 (A Study on the Phosphorus Removal from Wastewater by Eggshell)

  • 김민수;강선홍
    • 상하수도학회지
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    • 제18권2호
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    • pp.174-180
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    • 2004
  • This study is a fundamental research to test the applicability of abandoned eggshell as seed material for crystallization reaction. Eggshell was calcinated at $850^{\circ}C$ and ground to lesser than 0.42mm. The calcination characteristics of eggshell were examined by X-ray diffraction (XRD). The effect of initial calcium concentration, alkalinity, reaction temperature condition, seed dosage were studied by batch test. For the low concentration sample(P concentration is under 50mg/L), more than 90% of P can be removed. The effect of initial calcium concentration(0~120mg/L) was performed. At the result of the test, more than 50mg/L calcium concentration has high removal efficiency. Alkalinity effect was studied for synthetic solution(100mg/L initial P, 50mg/L calcium, 0.025% seed dosage) with 0~300mg/L bicarbonate alkalinities. For synthetic solution(100mg/L initial P, 50mg/L calcium, 100mg/L bicarbonate alkalinity, 0.025% seed dosage), the phosphorus concentration was examined with $10{\sim}35^{\circ}C$. In addition, calcinated eggshell was injected to swine wastewater to test the applicability to actual wastewater.

Response of germination rate and seed moisture contents to storage temperature and frequency of seed banking on seed soybean (Glycine max) for storage period

  • Na, Young-wang;Lee, Young-yi;Yi, Jung-yoon;Son, Eun-ho;Park, Hong-jae
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
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    • pp.288-288
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    • 2017
  • The seeds of soybean (Glycine max) were treated with different storage temperature for this study. The seeds of 3 accessions of soybean varieties in aluminum foil pack were used as materials. Storage temperature applied were $-18^{\circ}C$ and room temperature and seed banking (input after 3 days from output) frequencies were every 1, 6, and 12 month respectively for 9 years of storage period. As results seed banking frequency no affected to germination rate and seed moisture contents at $-18^{\circ}C$ storage room for seeds of soybean after 9 years. Germination rate of soybean seeds was changed from 96.2 % to 95.6 % averagely after 9 years of freezing ($-18^{\circ}C$) storage period. There were no differences in decreasing rate by number of seed banking frequency in soybean seeds. On the other hand, at room temperature germination rate of soybean seeds was decreased from 96.2 % to 27.3 % after 9 years which was decreased sharply to 55 % of initial viability after 6 years. The average rate of annual decrease of germination rate in soybean seeds was 38 % of initial viability at room temperature. Initial moisture contents of soybean seeds were 7.3 % and changed to 7.1 % at $-18^{\circ}C$ while it changed from 7.4 % to 7.0 % at room temperature after 9 years of storage period.

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Effects of Weed Interference and Starter Fertilizer on Subsequent Seed Germination and Vigour of Soybean (Glycine max [L.] Merr.)

  • Mohammadi, G.R.;Amiri, F.
    • 한국잡초학회지
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    • 제32권1호
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    • pp.17-24
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    • 2012
  • The study was conducted to investigate the effect of weed interference and starter fertilizer on subsequent soybean seed quality at the Agricultural Research Farm and Laboratory of Razi University, Kermanshah, Iran. Two factorial experiment was laid-outon a randomized complete block design with four replications. First factor was starter fertilizer levels (0 and 25 kg $ha^{-1}$) applied in the forms of monoammonium phosphate, the second factor was different weed interference periods consisted of five initial weed-free periods (in which, plots were kept free of weeds for 0, 15, 30, 45 and 60 days after crop emergence (DAE) and then weeds were allowed to grow until harvest) and five initial weed-infested periods (in which, weeds were allowed to grow for 0, 15, 30, 45 and 60DAE, after which the plots were kept free of weeds until harvest). Full season weedy condition reduced 100-seed weight, seed germination percentage and seedling dry weight by 25.9, 13.3 and 22.5%, respectively and increased mean germination time and seed electrical conductivity by 55.8 and 24.3%, respectively as compared with full season weed-free control. However, the traits under study were not significantly influenced when field was kept free of weeds for at least 45 DAE (R1) or weedy condition was continued for less than 30 DAE (V8). There was a significant and negative correlation between weed biomass and seed weight (r = -0.93), so that when weed free condition was less than 45 DAE or weed infested period was continued for at least 30 DAE, soybean plants produced wrinkled and underdeveloped seeds with lower weights and qualities. Moreover, soybean seed quality reduction due to weed interference was more evident when starter fertilizer was applied and weeds interfered with soybean from the beginning of the growing season. Information from the present study is beneficial in soybean seed production systems and where farmers use the harvested seeds for the following planting.

한정 용량 차량 경로 탐색 문제에서 이분 시드 검출 법에 의한 발견적 해법 (The Bisection Seed Detection Heuristic for Solving the Capacitated Vehicle Routing Problem)

  • 고준택;유영훈;조근식
    • 지능정보연구
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    • 제15권1호
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    • pp.1-14
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    • 2009
  • 본 연구에서는 한정 용량 차량 경로탐색 문제(CVRP, Capacitated Vehicle Routing Problem)에서 이분 시드 검출 방법(Bisection Seed Detection)을 이용한 휴리스틱 알고리즘을 제안하였다. 이 알고리즘은 3단계로 구성된다. 1단계에서는 improved sweep 알고리즘을 이용해서 초기 클러스터를 구성한다. 2단계에서는 1단계에서 얻은 각 클러스터에 대하여 이분 시드 검출 법을 이용해서 seed 노드를 선택하고, regret 값에 따라 각 경로에 고객 노드들을 삽입 함으로서 차량 이동 경로를 생성한다. 3단계에서는 tabu 탐색 방법과 노드 교환 알고리즘(node exchange algorithm)을 이용하여 2단계에서 얻어진 각 경로를 더욱 향상 시킨다. 본 논문의 실험에서는 제안된 휴리스틱이 비교적 빠른 시간 내에 최적 근사 값을 얻을 수 있음을 보였으며, 이는 빠른 실행 시간을 요구하는 실 업무에 유용하다.

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Successional Changes in Seed Banks in Abandoned Rice Fields in Gwangneung, Central Korea

  • Lee, Seon-Mi;Cho, Yong-Chan;Shin, Hyun-Chul;Oh, Woo-Seok;Seol, Eun-Sil;Park, Sung-Ae;Lee, Chang-Seok
    • Journal of Ecology and Environment
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    • 제31권4호
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    • pp.269-276
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    • 2008
  • In order to understand the role of seed banks for restoration, seed banks in abandoned rice fields in the Gwangneung National Arboretum, central Korea were investigated using the seedling emergence method. The study sites represented three stages: an initial stage dominated by forbs such as Persicaria thunbergii and Juncus effuses var. decipiens, a middle stage dominated by Salix, and a late stage dominated by Quercus aliena and Prunus padus (in nearby riparian forest chosen as a reference stand). DCA ordination arranged the stands according to the number of years since abandonment. CCA ordination identified the dominant environmental variables correlated most closely with Axes 1 and 2 as $Mg^{2+}$ (intraset correlation was 0.827) and $K^+$ (intraset correlation was -0.677), respectively. Species richness and diversity decreased from the initial stage (H'=2.61) to the middle (H'=1.79) and late (H'=0.75) stages. A total of 49 species $(/m^2)$ and 18,620 seedlings $(/m^2)$ emerged out of the seed bank samples. The DCA ordination and similarity analysis detected a large discrepancy between the composition of the actual vegetation and the seed bank. We conclude that the contribution of seed bank to restoration is low. However, seed bank may help the recovery of forbs after disturbance. Some of our results are consistent with the tolerance model of succession whereas others follow the trajectory of the facilitation model. More research on succession will be required to understand the underlying mechanisms.