• Title/Summary/Keyword: 불균형비율

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Experimental Analysis of Web Server on Multiprocessor (다중 처리기 기반 웹 서버 구조의 실험적 성능 분석)

  • Jeong, Jin-Guk
    • Journal of KIISE:Information Networking
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    • v.28 no.1
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    • pp.22-36
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    • 2001
  • WWW의 급격한 발전은 몇몇 웹 서버에 큰 과부하를 가져오게 하였다. 이로 인해 고성능 웹서버의 구축이 필요하게 되었는데 그중 프로세스의 오버헤드를 줄이기 위해 도입된 멀티 쓰레드 기법을 이용한 병행 웹 서버들이 많이 이용되게 되었다. 일반적으로 멀티 쓰레드 기법을 이용하는 웹 서버의 구조는 요구 기반 웹 서버 작업 기반 웹 서버 Thread Pool 구조 웹 서버 등으로 나눌수 있다. 본 논문에서는 이런 웹 서버들을 리눅스가 탑재되어 있는 다중 처리기상에 구현하였으며 다양한 환경하에서 성능을 비교 분석하였다 각각의 웹 서버들은 Pthread 라이브러리와 Socket 라이브러리를 이용하여 구현하였으며 여러 파라미터-CPU 개수 CGI 비율, 웹 서버구조, 파일크기 부하량 등-를 조절하면서 실험하였다 실험 결과 분석에 의하면 요구 기반 웹 서버에서는 하나의 CPU에서 수행이 되는 쓰레드의 개수가 많게 되면 성능이 저하되는 것을 볼 수 있었고 작업 기반 웹 서버에서는 단계사이의 불균형으로 인하여 큐에서의 대기 시간이 누적되면 성능이 저하되는 것을 볼수 있었다,. Thread Pool 구조의 웹서버는 쓰레드의 개수가 조절되고 큐에서의 대기 시간 또한 없앰으로 해서 다른 웹 서버에 비해 좋은 성능을 보임을 알 수 있었다. 이와 같은 실험 결과는 다중 처리기를 이용한 고성능 웹 서버를 구축하는데 있어서 이용될 수 있을 것이다.

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Examining the Collection of Public Libraries in Terms of Subject and Currency (공공도서관 소장자료 현황 분석 - 장서의 주제별 분포 및 노후화 현황 -)

  • Kim, Sun-Ae;Suh, Hye-Ran
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.20 no.1
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    • pp.151-164
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    • 2009
  • This study attempted to analyse the collections of public libraries in terms of their subject distribution and currency. It was expected that the analysis would give public librarians some suggestions as to their collection development policy making. This study team selected 423 Korean public libraries across the country and scrutinized the collections by their classes of Korean Decimal Classification(KDC) and publishing years. The study results indicated that there was some subject disproportion in public library collections. Literature and social sciences were accounting for 54.8% of whole collections. Currency of collections of public libraries could be said relatively excellent. It was found that 64.9% of whole collections had been published after 2000.

Anthropometric Measurements of the Upper and Lower Body Balance and Exercise Habit among Female College Students in Some Parts of the Gyeongnam (경남 일부 지역 여자 대학생의 상하체 균형 계측치와 운동 습관)

  • Kim, Young-Sik;Yoon, Im-Sil;Lee, Won-Joon;Nam, Jeong-Su;Yoon, Joong-Soo;Youn, Ryea-Min;Jung, Han-Na;Ko, Jae-Shik;Choi, Hyun-Ju
    • Journal of Life Science
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    • v.20 no.4
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    • pp.535-542
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    • 2010
  • This study was carried out to examine anthropometric parameters and related habits in female college students. Mean age, height, and body weight of the subjects in total (n=212) were 20.7 yrs, 161.8 cm, and 53.5 kg, respectively. Anthropometric parameters were measured by bioelectrical impedance analysis. Mean degree of obesity, body mass index (BMI), and waist-hip ratio (WHR) were 98.4%, $20.6\;kg/m^2$, and 0.80 respectively. Surprisingly, 63.7% of the subjects showed unbalanced weak upper bodies compared to their lower bodies. Therefore, they were divided into two groups: unbalanced weak upper body group (UU, n=135) and balanced upper body groups (BU, n=77). Bodyweight, degree of obesity, BMI, and WHR in the UU group were significantly lower than those in the BU group. Amounts of body protein, body fat, and body mineral in the UU group were also significantly lower than those of the BU group. Mid-arm muscle circumference of the UU group ($18.5{\pm}0.8\;cm$) was significantly lower than those of BU group ($20.4{\pm}1.2\;cm$), although mid-arm circumference of the UU group was not significantly different compared to those of the BU group. On a questionnaire on exercise habits, 1.5% of the UU group and 7.8% of the BU group answered that they exercised regularly, and 55.5% of the UU group and 31.2% of the BU group reported that they never exercised (p<0.01). Even in the subjects who exercised, the duration of the exercise was not sufficient because 38.4% of the UU group and 35.8% of the BU group answered that they exercised for less than 30 min. In conclusion, interventions in exercise habits may be needed for female college students who have unbalanced weak upper bodies.

Effects of Systematic Variation Application of Fe, Mn, Cu, and Zn on the Contents of N-compounds(Crude/Pure Protein) in Orchardgrass and White Clover (Fe, Mn, Cu 및 Zn의 Systematic Variation 시비가 Orchardgrass 및 White Clover의 질소화합물(조/순단백질) 함량에 미치는 영향)

  • Jung, Yeun-Kyu
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.24 no.3
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    • pp.183-192
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    • 2004
  • This pot experiment was conducted to investigate the effects of systematic variation application of Fe, Mn, Cu, and Zn on forage performance of orchardgrass and white clover. The treatments of systematic variation were 0/100, 25/75, 50/50. 75/25, and $100/0\%$ in the Fe/Cu(trial-1). Mn/Zn(trial-2), and Fe+Cu/Mn+Zn(trial-3), respectively The treatments of Fe/Mn/Cu/Zn(trial-4) were composed of $70\%$ for main element and $10\%$ for other 3 elements, respectively. 1. The contents of N-compounds in forages tended to be in inverse proportion to the yields. In the Mn/Zn trial, the 0/l00 to white clover resulted in the relatively high contents of soluble N-compounds and low ratio of pure protein/soluble N-compounds in company with a severe yield decrease. 2. In the Fe+Cu/Mn+Zn trial, the 0/100 and 100/0 resulted in the somewhat high contents of N-compounds in white clover. It was likely to be caused by the concentration effect derived from yield decrease. In addition, the 100/0 resulted in the relatively high content of soluble N-compounds and low ratio of pure protein/soluble N-compounds. The protein synthesis in white clover was likely to be negatively influenced by the 100/0. 3. In the Fe/Mn/Cu/Zn trial, white clover showed the low contents of crude and pure protein at the 1st cut. It was likely to be caused by the unbalanced mutual ratios derived from the high application levels of each single element. 4. In white clover at the 5th cut, the 0/100 of Mn/Zn and 100/0 of Fe+Cu/Mn+Zn resulted in the relatively high content of K. It was likely to be caused by the concentration effect derived from yield decrease.

Falls among Community Dwelling Elderly People: Prevalence and Associated Factors (일부 농촌지역 노인들의 낙상발생과 관련된 요인)

  • Cho, Young-Chae;Yoon, Hyun-Suk
    • Journal of agricultural medicine and community health
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    • v.29 no.2
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    • pp.223-235
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    • 2004
  • Objectives: This study was to evaluate the actual condition of falls among community-dwelling elderly people and its related factors to prepare for the establishment of comprehensive prevention programs of senior population. Methods: The study subjects included 460 home residents over 65 years in a district of Chungnam Province and interviews were given to all of them, asking about experiences of falls and their related factors. The analysis of study results came to the following conclusions. Results: The rate of falls among total subjects was 35.5%. With the percentage by age and sex, over 70's and female were significantly higher than male(p=0.000) and under 69 (p=0.008). The groups with poor visual acuity and hearing ability had higher rate of falls than the normal groups based on their health status. In terms of place they experienced falls, out-door occurrence accounted for 53.4% of total falls, which was higher 46.6% of in-door. By season when falls are experienced, "winter" showed the greatest rate, and by time of the day, evening had the highest rate. By causes of falls, "Slippery ground"accounted for 30.5% and "Tumbled over" 23.5% of total falls, respectively, showing the major role of environmental causes for falls. For individual factors, "Irritability" and "Carelessness" occupied 11.3%, 10.8% of total falls, respectively. The Odds Ratios for falls in women was 2.19 times higher than in men, and those in 70's are 2.01 times higher than in 60's, and those with abnormal BMI was 3.68 times higher than in normal groups, and those with perceived symptoms was 1.94 times higher than those without. Conclusions: It is suggested that more consideration should be directed toward taking comprehensive and systematic prevention measures ranging from setting-up the injury-protective environments to allowing senior citizens to have competence in ADL activity as well as proper general health conditions, considering the higher rate of falls for elderly persons in a rural part of this country than that of western countries and the greater proportion of falls which can be ascribed to environmental factors.

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Qualitative Equity of Neighborhood Parks in Daegu According to Socioeconomic Status (사회경제적 지위에 따른 대구시 근린공원 질적 가치 형평성)

  • Jung, Mijeong;Jung, Taeyeol
    • Journal of the Korean Institute of Landscape Architecture
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    • v.48 no.2
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    • pp.45-55
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    • 2020
  • In terms of environmental justice, urban parks play a pivotal role in imperative amenities allowing for physical activity. The reasonable distribution of urban park services must be considered in terms of community demand and the context of the park. The purpose of this study is to analyze the inequity of qualitative park service according to the socioeconomic status(SES) in Daegu. The qualitative service was assessed for 82 neighborhood and walking-distance parks by utilizing the NGST(Neighborhood Green Space Tool). The inequity was analyzed by SES variables(ratio of basic living recipients, ratio of single-parent families, average housing sales, dilapidated dwelling ratio, and park area per capita). The features of the qualitative equity in Daegu is as follows. First, urban park planning in Daegu is in parallel with the development of residential areas rather than the local policy. The development pattern of parks stretching from center of the city to outskirts clearly dissociates the city based on socioeconomic status. The parks in the center are relatively old and poorly managed. Second, overall neighborhood parks lacked recreational facilities. The facilities are significantly influenced by the housing values around them. The lower the recreation facility score, the higher the floor gradient of the urban parks constraining physical activities. Third, the quantitative supply of parks has nothing to do with the quality of the urban parks. Green space distribution is highly dependent on natural park areas, so the park area per capita cannot be a standard for assessing qualitative equity.

Interpreting Soil Tests for Turfgrass (잔디 토양 분석의 해석)

  • Christians, Nick;Joo, Young-Kyoo;Lee, Jeong-Ho
    • Asian Journal of Turfgrass Science
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    • v.20 no.2
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    • pp.223-235
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    • 2006
  • Soil testing laboratories unfamiliar with turfgrasses will often overestimate the plant's need for phosphorus and underestimate the need for potassium. This is partly due to differences in rooting between grasses and many garden plants and crops. The grasses are generally more efficient in extracting phosphorus from the soil, reducing their need for phosphorus fertilizer. The fact that crop yield is often the primary objective in field crop production, and is usually of little interest in turfgrass management, may affect soil test interpretation for potassium. Potassium levels above those required for maximum tissue yield of grasses may improve stress tolerance and turfgrasses will usually benefit from higher applications of this element. There are also diffrrences in soil testing philosophies. Some laboratories use the sufficiency level of available nutrients(SLAN) approach, whereas others prefer the basic cation saturation ratio(BCSR) approach. Some will use a combination of the two methods. The use of the BCSR theory easily lends itself to abuse and questionable fertilizer applications and products are sometimes recommended citing imbalances in cation ratios. The usefulness of the BCSR ratio theory of soil testing varies with soil texture and interpretations on tests performed on sand-based media are particularly a problem. Other soil testing problems occur when sand-based media used on sports fields and golf greens contain free calcium carbonate. The ammonium acetate extractant at pH 7.0 dissolves excessive amounts of calcium that can bias cation exchange capacity measurements and measurements of cation ratios. Adjusting the pH of the extractant to 8.1 can improve the accuracy of the testing procedure for calcareous media.

Perception of Native and Prohibitive Foods in Hansan - Do Area (한산도 지역의 향토음식과 금기식품에 대한 인식)

  • 박영선
    • Korean journal of food and cookery science
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    • v.15 no.1
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    • pp.23-36
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    • 1999
  • The purpose of this study was to investigate the kinds of native and prohibitive foods in Hansan-Do area. The kinds of the prohibitive foods and the reason prohibiting those from pregnant or lactating woman, fisherman and sick people were surveyed by using a guestionnaire from 1994 to 1998. The results showed that Chungmu Gimbab was perceived highly as a native foods and the reason for prohibiting specific foods was not based on scientific evidences.

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Uncertainty Assessment of CANDU Void Reactivity using MCNP-4C with ENDF/B-VII(I) (ENDF/B-VII기반 MCNP-4C를 이용한 CANDU-6 기포반응도 불확실성 평가(I))

  • Hong, S.T.;Kwon, T.A.;Lee, Y.J.;Oh, S.K.;Lee, S.K.;Kim, M.W.
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 2008.04a
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    • pp.69-75
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    • 2008
  • 기포반응도는 월성발전소를 비롯한 CANDU형 원자로의 주된 안전성 쟁점사안으로 끊임없이 논의되어 왔다. 이는 설계기준사고가 노심에서 열에너지 불균형이 원인이 되어 기준이상의 핵연료 파손과 방사성물질 누출로 발전할 위험이 있는 사건들로 정의될 때, 사건 진행 과정에 기포반응도 증가는 조기에 운전중단을 실패할 경우 출력폭주로 이어지므로 사건의 결말이 중대사고로 전환될 위험이 크기 때문이다. 본 연구는 공개된 최신 핵자료인 ENDF/B-VII.0를 NJOY.99로 처리한 연속에너지 반응단면적 라이브러리를 구축하고 MCNP-4C에 접속하여 37봉 천연우라늄 핵연료다발의 표준노심격자에 대한 기포반응도를 시뮬레이션하여, 지금까지 각종문헌에 제시된 값들과 비교, 종합하므로 내제된 불확실성을 추정하는 내용이다. ENDF/B-VII.0 기반 MCNP-4C의 CANDU 노심격자 모델은 동일한 핵자료와 핵종농도를 사용한 WIMS-IAEA 모델과 비교할 때, 초기 노심의 임계도 오차 약 3.51mk가 연소 진행에 따라 $7.5\times10^{-4}mk$/MWD/teU의 비율로 감소하는 것으로 나타났다. 또한 MCNP-4C 예측기포반응도는 초기노심에서 기포율 50% 및 100%에 대해 각각 8.38 및 15.96mk, 평형노심에서 7.68 및 14.72mk로 계산된다. 이는 월성 2, 3, 4 FSAR의 초기노심 및 평형노심에서 100% 기포상태에 대한 값, 약15.0 및 10.6mk와 비교할 때, 초기노심은 약 1.0mk 평형노심은 약4, 1mk 보수적이지만, 다른 연구결과들과는 최대오차 ${\pm}1{\sim}2mk$ 이내에서 잘 일치하는 것으로 평가되었다. 본 연구는 CANDU 노심의 기포반응도 불확실성 요인의 규명 및 영향평가를 위한 노력의 일부로서 앞으로 감속재의 붕산농도 변화, 감속재 및 냉각재의 중수 순도 변화, 기기노화에 의한 격자 구조 및 물성 변화, 중성자속 및 출력 분포 불균형, 반응도조절장치의 위치, 등 주요 설계변수의 변화에 대한 반응도영향 분석연구를 계속할 계획이다.

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Determinants of Credit Default Swap Spreads: The Case of Korean Firms (한국 기업들의 신용부도스왑 스프레드에 대한 결정요인 분석)

  • Park, Yoon-S.;Kim, Han-Joon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.10
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    • pp.4359-4368
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    • 2011
  • Among several macroeconomic missteps blamed for the recent global financial crisis including the social problems of income distribution and the lack of proper financial remedies, two of them have received particular attention: the global BOP(Balance of Payment) imbalance and the misguided monetary policy. Such BOP imbalance was blamed for massive foreign exchange investment flows from Asia into the U.S., triggering the financial and real estate bubble in America. The latter refers to the excessively loose monetary policy of the U.S. Federal Reserve, which pushed financial institutions and households into reckless investment behavior in search of higher returns. Given the abuse of certain innovative financial techniques and new investment instruments that have been created in recent decades, both collateralized debt obligations (CDOs) and credit default swaps (CDS) enjoyed a symbiotic and toxic relationship prior to the financial crisis This paper is organized as follows: The first section analyzes the real causes of the recent financial crisis. The second details the role of CDOs and CDS. Then, to identify key determinants of the CDS spreads in an emerging capital market, the sample data of major Korean firms' CDS spreads are used to estimate the risk premium by utilizing the multiple regression analysis. The empirical test result indicates that Korean 3-year treasury bond rate(TYIELD), market to book value ratio(MV/BV), and assets size(INASSETS) are shown to demonstrate statistically significant influences on the changes of the CDS premium for sample firms.