• 제목/요약/키워드: Individual number

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시간이 연속인 마르코프 체인하에서 개체수 과정에 관한 연구 (A Study of Individual Number Process Under Continuous-Time Markov Chains)

  • 박춘일;김명철
    • 한국항해학회지
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    • 제16권1호
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    • pp.94-97
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    • 1992
  • In this paper, the individual number of the future has depended not only upon the present individual number but upon the present individual age, considering the stochastic process model of individual number when the life span of each individual number and the individual age as a set, this becomes a Markovian. Therefore, in this paper the individual is treated as invariable, without depending upon the whole record of each individual since its birth. As a result, suppose {N(t), t>0} be a counting process and also suppose $Z_n$ denote the life span between the (n-1)st and the nth event of this process, (n{$geq}1$) : that is, when the first individual is established at n=1(time, 0), the Z$Z_n$ at time nth individual breaks, down. Random walk $Z_n$ is $Z_n=X_1+X_2+{\cdots}{\cdots}+X_A, Z_0=0$ So, fixed time t, the stochastic model is made up as follows ; A) Recurrence (Regeneration)number between(0.t) $N_t=max{n ; Z_n{\leq}t}$ B) Forwardrecurrence time(Excess life) $T^-I_t=Z_{Nt+1}-t$ C) Backward recurrence time(Current life) $T^-_t=t-Z_{Nt}$

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생활체육시설의 지역 간 격차에 따른 19세 이상 인구의 우울증상 (Depressive Symptoms of the Population Aged 19 and Over due to Regional Gaps in Sports Facilities)

  • 심형섭;김봄결;김도희;김태현
    • 보건행정학회지
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    • 제32권1호
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    • pp.63-72
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    • 2022
  • Background: Depression is a common disease around the world. Many studies are showing that mental health can be improved through physical activity, and daily regular exercise can reduce the negative effects of depression or depressive symptoms. In order to promote individual physical activity, a physical activity-friendly environment must precede. Therefore, this study attempted to confirm whether the number of sports facilities for all affects individual depression. Methods: Among the respondents to the 2018 Community Health Survey, data from 181,086 people excluding missing value were used. Descriptive and chi-square tests were performed to understanding the general characteristics of individual level variables. A multilevel logistic regression was conducted to confirm the effect of individual and regional level variables on depressive symptoms. Results: As a result of confirming the effect of individual characteristics on depressive symptoms, it was confirmed that both socioeconomic and health behavior factors had an effect. Similar results were shown in a model that considered regional level variables, and in the case of the number of sports facilities per population, people who belongs to smaller areas were more likely to have depressive symptoms (odds ratio, 0.98; 95% confidence interval, 0.97-0.99). Conclusion: As a result of the analysis, it was confirmed that both individual level and regional level variables had a significant effect on depressive symptoms. This suggests that not only individual level approaches but also regional level approaches are needed to improve individual depressive symptoms In particular, it may be possible to consider to increase the number of sports facilities in areas where the prevalence of depressive symptoms is high and the number of sports facilities is insufficient.

앉은부채 (Symplocarpus Renifolius) 개체군의 동태 2.종자생산 (Population Dynamics of Symplocarpus renifolius (2. Seed production))

  • Kang, Hyun-Jung;Min, Byeong-Mee
    • The Korean Journal of Ecology
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    • 제17권4호
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    • pp.463-469
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    • 1994
  • For better understanding of population dynamics of Symplocarpus renifolius, some aspects of seed production were studied in natural populations for 3 years. The rate of reproducing plants (RP) was 8.06% among the whole studied. The RPs were 0.0% in leaf size class under 500cm2 per individual, and 3.6% in 500~1,000cm2, and 44.3% in over 3,000cm2. The resource allocated to sexual organ was 11.6% of total biomass at the end of growing season, and that to belowground was about 80% regradless of presence or absence of sexual organ. In the previous and the next years of seed production, the energy allocated to sexual organ didn't affect the changes of leaf size, year by year. After flowing season. Especially, a large number of sex organ were degraded in April, a period of pollination and fertilization. The number of seeds per individual was degraded in April, a period of pollination and fertilization. The number of seeds per individual was 13~22 and didn't relate to leaf size. But the weight per seed increased along leaf size per individual. Therefore, in S.renifolius population, large individual produced large seeds rather than many seeds.

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조류가 강한 서해 하구에서 수동어구를 이용한 하구역 유영생물의 효율적 채집 (Effective sampling of estuarine fauna by a passive net in theWest Sea of Korea occurring strong tide)

  • 황선도;임양재
    • 수산해양기술연구
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    • 제47권4호
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    • pp.338-343
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    • 2011
  • To obtain the effective sampling estuarine fauna by a passive net in the West Sea of Korea occurring strong tide, catch were collected by bag nets with various sampling trials off Ganghwa Island in November 2009. We compared the difference of community structures (on spring tide vs. neap tide, total sample vs. subsample and 4 nets vs. 1 net) with each species composition as a sampling unit by the Pearson chi-square test. Number of individual at the spring tide was more abundant than that at the neap tide (p<0.0001) although number of species at the spring tide was not significantly different with that at the neap tide (p=0.174). Both number of species (p=0.138) and number of individual (p=0.096) were not significantly different between total sample and random subsample. Number of species was not significantly different between the subsample by 1 net and the subsample by 4 nets (p=0.515), but number of individual was a little different on both samples (p=0.024). In conclusion, we suggest the subsample by 1 net at spring tide as the effective sampling estuarine fauna by a passive net in the West Sea occurring strong tide.

강원도에 집단 도래하는 천연기념물 겨울철새의 생태조사 및 질병발생 가능성에 관한 연구 (Study of ecological investigation and disease occuring possibility natural monument wintering-birds in Gangwon-do)

  • 김종택;김현철;박인철;정기수;장환
    • 한국동물위생학회지
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    • 제30권3호
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    • pp.445-457
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    • 2007
  • This report studied the individual number, their favorite habitat, and change pattern of family and group number in Cheolwon Basin, starting in the early Oct. 2004 until late March. 2005 to investigate the ecological features of the Red-crowned Crane and the White-naped Crane. The Cranes arrived Cheolwon Basin in mid-October until next mid-March, and passed the winter in mid-November until next late-February The most visiting number amounted to 550 individuals and, that period was the most frosting mid-January to mid-February. The White-naped Crane visited Cheolwon Basin in autumn, the early winter and spring. Approximately, the wintering-number is 550 individuals, also, the mid-March was the peak-period of arrival and, the number amounted to 2,162 individuals. The cranes chose the farming area around mountains as their wintering habitat and were less likely to choose the farming area around lake as habitat. The Red-crowned Crane and the White-naped Crane showed the different periodical pattern in familial and group numbers. In case of the crane, the familial pattern was stable, but varied in grouping number, and this pattern was similar to the variation of overall individual number. And, also, the most grouping number was shown in the most freezing period of wintering period. The White-naped Crane showed the similar pattern of the Red-crowned Crane that is, stable family number and varying group number, this pattern affected the total number of entire individuals. Grouping number increased in migration period. Parasite infection rate is G japonensis 35.0%, G vipio 38.7%.

Breeding of Korean Raisin Tree (Hovenia dulcis var. koreana Nakai) for High Productivity in Korea

  • Kim, Sea-Hyun;Han, Jingyu
    • 한국육종학회지
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    • 제40권4호
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    • pp.371-376
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    • 2008
  • For the purpose of breeding a high-yield superior variety of Korean raisin tree (Hovenia dulcis var. koreana Nakai), whose value as an edible and medicinal resource is increasing, tree candidates for superior individuals were selected from its 11 habitats in Korea from 1996 to 1998. A clone bank preserve was created in 1998 with 70 clones proliferated by grafting; the fruition traits (e.g., the number of fructified laterals, the average number of bunches per fructified lateral, the average number of bunches per fruiting lateral, the fruitpetiole weight per individual, and the yield per individual) of 47 clones that had bloomed and borne fruit were investigated and analyzed in 2002; five upper-ranking clones whose yield per individual exhibited a 261% improvement against the total average were picked in 2005; and three clones, including 'Poong-Sung 1', that showed a difference in their fruit petiole ripening stage, were finally selected in 2007 as high-yield new cultivars of Korean raisin tree.

새 연대순 도서기호법의 연구 (A Study of New Chronological Book Numbers)

  • 리재철
    • 한국문헌정보학회지
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    • 제12권
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    • pp.7-37
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    • 1985
  • In most of the modern libraries throughout the world, it is popular to adopt the author number which arranges the books or entries in alphabetical order of their author's names within the same ultimate class. However, viewed historically, that was the Western practice never used in the East before. Traditionally chronological order was followed in the East. Book number not only individualizes the books within the same class but also makes it easy for the user to choose and find out the relevant materials. In this respect, chronological book number is decidedly superior to all kinds of book number systems ever have been existed. Especially in these days of rapid obsolescence of documents and with serious problems of storage of documents, the chronological order seems to be the most modern and future-oriented of all other book number systems because it distinguishes clearly new materials from aged materials by the date of publication and controls the stack spaces mechanically and effectively. This writer devised New Chronological Book Numbers adaptable to both the Eastern and Western materials, and the system has been adopted at Yonsei University Library. The features of the system are as follows: (1) It is easy to type the call number in cataloging the Eastern and Western materials. That is because the structure of the chronological number is pure numerical notation by taking the last two figures of the year within twentieth century(e.g. 85 for AD 1985), that is 1900s, and the last three figures of the year from twenty-first century to thirtieth century, that is 2000s. (2) It does not make all classes have chronological number uniformly. Within the classes for individual biographies, genealogies and collections of biography of specific family, books about individual organization, individual literary and artistic works, philosophical works of the famous philosophers, books and its facsmile editions published before 1900, new editions, translations, commentaries, serials, chronological number is assigned to the author number as in the past. (3) It separates the Eastern materials from the Western materials and makes the typing easy in cataloging. That is because the subarrangement within the same chronological book number is made by the accession order which uses 'panjol-ponmun' or the characters of basic syllabic table of Korean alphabet in case of the Eastern materials and Roman alphabet in case of the Western materials.

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한라산(영실) 장기생태연구(LTER) 조사지 구상나무 숲 식생 변화 (Vegetation Change of Long-Term Ecological Research (LTER) Site of Abies koreana Forests in Hallasan Mountain (Yeongsil Area))

  • 송국만;김재훈
    • 한국환경복원기술학회지
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    • 제21권1호
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    • pp.1-12
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    • 2018
  • 본 연구는 한라산 영실 지역의 구상나무 숲에서 식생구조와 종다양성 지수의 변화를 분석하여 장기생태연구의 기초자료를 구축하기 위해 실시하였다. 조사결과 1ha당 목본식물은 1,781개체에서 804개체(45.1%)가 증가한 2,585개체였으며, 살아 있는 구상나무는 796개체로 큰 변화는 없었지만 죽은 개체는 190개체에서 312개체로 122개체(64.2%)가 증가하였다. 기타 수종은 살아있는 개체가 982개체에서 1,789개체로 807개체(82.2%)가 증가했으며, 죽은 개체는 10개체에서 31개체가 증가한 41개체였다, 평균 중요도지수 분석결과 상층 구상나무는 감소하였고, 하층 병꽃나무, 산철쭉, 함박꽃나무는 증가하였다. 종다양도는 최대종다양도 대비 상층 6.7%, 하층 7.2%가 증가하였다. 줄기 형태 분석결과 구상나무는 AS형이 700개체로 가장 많았으며, AS형>AL형>DS형>DB형에서 AS형>DS형>AL형>DB형으로 변하였다. 기타 수종은 AS형이 1,580개체로 가장 많았으며, AL형>AS형>AF형>AB형에서 AS형>AL형>AB형> AD형으로 변경되었다. 치수 발생 변화는 2014년에 420개체에서 2016년 453개체로 증가하였다. 2014년에 살아있던 개체 중에서 23개체는 죽었으며, 3년생 미만의 새로운 개체가 33개체 새롭게 발생하였다. 2014년 이후 죽은 치수와 새롭게 발생한 치수는 2년생 치수가 가장 많았다. 영실 구상나무 숲은 구상나무의 고사목과 구상나무를 제외한 기타 수종의 밀도가 급격히 증가하고 있고 치수발생이 급격히 감소하고 있어 식생구조의 변화가 빠르게 발생하고 있다. 따라서 식생변화를 모니터링 할 수 있는 지속적인 장기 생태연구가 필요하고 효율적인 자생지 복원 연구의 기초자료로 활용가능하다.

서산 간척지의 염도와 벼의 생육에 관한 연구 (Studies on Salinity and Growth of Rice at Seosan Reclaimed Land)

  • 이희선;김옥봉
    • The Korean Journal of Ecology
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    • 제20권5호
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    • pp.367-373
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    • 1997
  • The effects of salinity on the growth and production of rice were studied at Seosan reclaimed land from July to October, 1995. The plant height, the number of living aleaves, dead leaves and total leaves, the number of the grains and the dry weight of the grains per individual, and the dry weight of above the ground in $25cm{\times}25cm$ quadrat were investigated on 5 plots whers were different salinity. The plant height, the number of living leaves and total leaves and the number of grains and the dry weight of grains per individual, and the dry weight of above the ground decreased as the salinity of water increase and the number of dead leaves of rice increased as the salinity of water decrease. The effect of salinity on the reproductive production is severer than the vegetative production. Because of the salinity, the growth and the production of the rice at Seosan reclaimed land are worse than the normal rice field.

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Analysis of Spatial Distribution of Hypertension Prevalence and Its Related Factors based on the Model of Social Determinants of Health

  • Kim, Min Jung;Park, Nam Hee
    • 지역사회간호학회지
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    • 제29권4호
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    • pp.414-428
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    • 2018
  • Purpose: The purpose of this study is to identify the spatial distribution of hypertension prevalence and to investigate individual and regional-level factors contributing to the prevalence of hypertension in the region. Methods: This study is a cross-sectional research using the 2015 Community Health Survey. Total 64,473 people from 7 metropolitan cities were used for the final analysis. Geoda program was adopted to identify the regional distribution of hypertension prevalence and analyzed by descriptive statistics, one-way ANOVA and correlation analysis using SPSS statistics 23.0 program. Multi-level analysis was performed using SPSS (GLMM). Results: The prevalence of hypertension was related to individual level factors such as age, monthly household income, normal salt intake, walking practice days, and regional level factors including number of doctors per 10,000 population, number of parks, and fast food score. Besides, regional level factors were associated with hypertension prevalencies independently without the effects of individual level factors even though the influences of individual level factors ware larger than those of regional factors. Conclusion: Respectively, both individual and regional level factors should be considered in hypertension intervention programs. Also, a national level research is further required by exploring various environmental factors and those influences relating to the hypertension prevalence.