• Title/Summary/Keyword: 성장곡선 모형

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A Study on the Development of the New Technology Valuation System using Case-Based Reasoning (사례기반추론을 이용한 신기술 가치평가 시스템개발에 관한 연구)

  • Park, Ki-Nam
    • The Journal of Society for e-Business Studies
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    • v.9 no.4
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    • pp.103-116
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    • 2004
  • It is needed to transfer the technology actively which has already developed to improve a up-to-date technology and foster the technological innovation. The technology transfer also can bring about a commercial success. To promote the technology transfer, it is needed to develop a new technology valuation model for a specific technology from a objective point of view, as well as to equip an institution such as the technology transfer center. The technology valuation from a objective point of view is of importance as the basic information for the price negotiation between a technology-buyer and a technology-seller. This paper takes aim at investigating a new technology valuation model and developing a technology valuation system for promoting the technology transfer. A new technology valuation system is developed as a web-enabling base. Using this users are able to estimate the value of specific technology on a real time efficiently.

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Estimation of the Survival Rate in Fish Population -Mackerel and Horse Mackerel in the Coastal Waters of Korea- (어획대상 어류의 생잔율 추정 -한국 연안의 고등어, 전갱이-)

  • SHIN Sang-Taek
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.14 no.4
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    • pp.253-259
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    • 1981
  • A study was made to find out a new method of calculating the survival rate of a fish population from length composition and growth equation. 1. In the steady state of the fish population, let the total mortality rate be z, the age of complete recruitment a, the oldest age in the catch b and the average between the age of complete recruitment and the oldest age in the catch Ut, then we have $$U_{t}\;=\;\frac{a-b\;{e xp}\{-z(b-a)\}}{1-\;{e xp}\{-z(b-a)\}}+\frac{1}{z}{\cdots}{\cdots}{\cdots}{\cdots}{\cdots}$$(1) And let b be infinite, then we obtain $$Z=\frac{1}{U_t-a}{\cdots}{\cdots}{\cdots}{\cdots}{\cdots}{\cdots}$$ (2) 2. Calculating numerical value of $U_t$ from age composition table and growth equation, and substitute in (1) for it, we may obtain the value of z and $e^{-z}$. 3. This method is applied to a case of mackerel and horse mackerel in the coastal waters of Korea, with the following results : Total mortality rate-Mackerel : 0.87909, Horse mackerel : 2.22327, Survival rate-Mackerel : 0.41516, Horse Mackerel : 0.10825, 95 percent confidence Interval of survival rate-Mackerel : $0.35966{\sim}0.47264$, Horse mackerel : $0.06897{\sim}0.14974$

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Breeding and Development of the Tscherskia triton in Jeju Island (제주도 서식 비단털쥐(Tscherskia triton)의 번식과 발달)

  • Park, Jun-Ho;Oh, Hong-Shik
    • Korean Journal of Environment and Ecology
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    • v.31 no.2
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    • pp.152-165
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    • 2017
  • The greater long-tail hamster, Tscherskia triton, is widely distributed in Northern China, Korea and adjacent areas of Russia. Except for its distribution, biological characteristics related to life history, behavior, and ecological influences for this species are rarely studied in Korea. This study was conducted to obtain biological information on breeding, growth and development that are basic to species-specific studies. The study adopted laboratory management of a breeding programme for T. triton collected in Jeju Island from March, 2015 to December, 2016. According to the study results, the conception rate was 31.67% and the mice in the large cages had a higher rate of conception than those in the small cages (56.7 vs. 6.7%). The gestation period was $22{\pm}1.6days$ (ranges from 21 to27 days), and litter size ranged from 2 to 7, with a mean of $4.26{\pm}1.37$ in the species. The minimum age for weaning was between $19.2{\pm}1.4days$ (range of 18-21 days). There were no significant differences by sex between mean body weight and external body measurements at birth. However, a significant sexual difference was found from the period of weaning (21 days old) in head and body length, as well as tail length (HBL-weaning, $106.50{\pm}6.02$ vs. $113.34{\pm}4.72mm$, p<0.05; HBL-4 months, $163.93{\pm}5.42$ vs. $182.83{\pm}4.32mm$, p<0.05; TL-4 months, $107.23{\pm}3.25$ vs. $93.95{\pm}2.15mm$, p<0.05). Gompertz and Logistic growth curves were fitted to data for body weight and lengths of head and body, tail, ear, and hind foot. In two types of growth curves, males exhibited greater asymptotic values ($164.840{\pm}7.453$ vs. $182.830{\pm}4.319mm$, p<0.0001; $163.936{\pm}5.415$ vs. $182.840{\pm}4.333mm$, p<0.0001), faster maximum growth rates ($1.351{\pm}0.065$ vs. $1.435{\pm}0.085$, p<0.05; $2.870{\pm}0.253$ vs. $3.211{\pm}0.635$, p<0.05), and a later age of maximum growth than females in head and body length ($5.121{\pm}0.318$ vs. $5.520{\pm}0.333$, p<0.05; $6.884{\pm}0.336$ vs. $7.503{\pm}0.453$, p<0.05). However, females exhibited greater asymptotic values ($105.695{\pm}5.938$ vs. $94.150{\pm}2.507mm$, p<0.001; $111.609{\pm}14.881$ vs. $93.960{\pm}2.150mm$, p<0.05) and longer length of inflection ($60.306{\pm}1.992$ vs. $67.859{\pm}1.330mm$, p<0.0001; $55.714{\pm}7.458$ vs. $46.975{\pm}1.074mm$, p<0.05) than males in tail length. These growth rate constants, viz. the morphological characters and weights of the males and females, were similar to each other in two types of growth curves. These results will be used as necessary data to study species specificity of T. triton with biological foundations.

Influence of Protective and Risk Factors on Delinquent Behavior Trajectories (청소년 비행행동의 궤적에 영향을 미치는 보호요인과 위험요인)

  • Lee, Sang-gyun
    • Korean Journal of Social Welfare Studies
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    • no.39
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    • pp.315-342
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    • 2008
  • The aim of this study was to examine growth trajectories of delinquent behaviors during adolescence. In addition, the effects of protective and risk factors that might account for individual difference in the level of delinquent behaviors and in the rate of change were examined. Four waves of data in the Korea Youth Panel Survey(KYPS) were used to analyze the linear growth modeling. The sample consisted of 3346 adolescents who were assessed at 4 measurement waves with approximately 1-year intervals. The results showed significant individual differences in both final level of delinquent behaviors and in the rate of change across 3 measurement occasions. Adolescent gender, family's socioeconomic background predicted the final level and the rate of change of delinquent behaviors. The protective effects of positive parenting and self-control were significantly associated with problem behaviors and the risk effects of the association with deviant peers and negative stigma were significant on the final level of delinquency. Self-control and deviant peer affiliation had differential influences over time significantly. Practice and policy implications as well as further research topic were discussed in the light of searching for important factors in preventing adolescent problem behaviors.

Long-term runoff simulation using rainfall LSTM-MLP artificial neural network ensemble (LSTM - MLP 인공신경망 앙상블을 이용한 장기 강우유출모의)

  • An, Sungwook;Kang, Dongho;Sung, Janghyun;Kim, Byungsik
    • Journal of Korea Water Resources Association
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    • v.57 no.2
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    • pp.127-137
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    • 2024
  • Physical models, which are often used for water resource management, are difficult to build and operate with input data and may involve the subjective views of users. In recent years, research using data-driven models such as machine learning has been actively conducted to compensate for these problems in the field of water resources, and in this study, an artificial neural network was used to simulate long-term rainfall runoff in the Osipcheon watershed in Samcheok-si, Gangwon-do. For this purpose, three input data groups (meteorological observations, daily precipitation and potential evapotranspiration, and daily precipitation - potential evapotranspiration) were constructed from meteorological data, and the results of training the LSTM (Long Short-term Memory) artificial neural network model were compared and analyzed. As a result, the performance of LSTM-Model 1 using only meteorological observations was the highest, and six LSTM-MLP ensemble models with MLP artificial neural networks were built to simulate long-term runoff in the Fifty Thousand Watershed. The comparison between the LSTM and LSTM-MLP models showed that both models had generally similar results, but the MAE, MSE, and RMSE of LSTM-MLP were reduced compared to LSTM, especially in the low-flow part. As the results of LSTM-MLP show an improvement in the low-flow part, it is judged that in the future, in addition to the LSTM-MLP model, various ensemble models such as CNN can be used to build physical models and create sulfur curves in large basins that take a long time to run and unmeasured basins that lack input data.

Trends in Health across Educational Groups (교육집단별 건강 추세에 대한 분석)

  • Kim, Jin-Young
    • Korea journal of population studies
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    • v.34 no.1
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    • pp.99-127
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    • 2011
  • This study examines whether educational differentials in health are greater in more recent cohorts in Korea. This study utilizes latent growth-curve modeling to examine intercohort trends in health for three educational subgroups, using panel data (2003-2007) based on a national probability sample of 9,639 adults. Among young and middle adults with less than a high school diploma, the 4-year newer cohort demonstrated better health at the same age, implying a favorable trend. Middle and older adults with college level and a high school diploma also enjoyed favorable trends in health. This study suggests the possibility that the education-based overall disparity in health is increasing, but there are variations in the trend depending on age group. The increasing disparity mainly occurred among older adults.

Forecasting Substitution and Competition among Previous and New products using Choice-based Diffusion Model with Switching Cost: Focusing on Substitution and Competition among Previous and New Fixed Charged Broadcasting Services (전환 비용이 반영된 선택 기반 확산 모형을 통한 신.구 상품간 대체 및 경쟁 예측: 신.구 유료 방송서비스간 대체 및 경쟁 사례를 중심으로)

  • Koh, Dae-Young;Hwang, Jun-Seok;Oh, Hyun-Seok;Lee, Jong-Su
    • Journal of Global Scholars of Marketing Science
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    • v.18 no.2
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    • pp.223-252
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    • 2008
  • In this study, we attempt to propose a choice-based diffusion model with switching cost, which can be used to forecast the dynamic substitution and competition among previous and new products at both individual-level and aggregate level, especially when market data for new products is insufficient. Additionally, we apply the proposed model to the empirical case of substitution and competition among Analog Cable TV that represents previous fixed charged broadcasting service and Digital Cable TV and Internet Protocol TV (IPTV) that are new ones, verify the validities of our proposed model, and finally derive related empirical implications. For empirical application, we obtained data from survey conducted as follows. Survey was administered by Dongseo Research to 1,000 adults aging from 20 to 60 living in Seoul, Korea, in May of 2007, under the title of 'Demand analysis of next generation fixed interactive broadcasting services'. Conjoint survey modified as follows, was used. First, as the traditional approach in conjoint analysis, we extracted 16 hypothetical alternative cards from the orthogonal design using important attributes and levels of next generation interactive broadcasting services which were determined by previous literature review and experts' comments. Again, we divided 16 conjoint cards into 4 groups, and thus composed 4 choice sets with 4 alternatives each. Therefore, each respondent faces 4 different hypothetical choice situations. In addition to this, we added two ways of modification. First, we asked the respondents to include the status-quo broadcasting services they subscribe to, as another alternative in each choice set. As a result, respondents choose the most preferred alternative among 5 alternatives consisting of 1 alternative with current subscription and 4 hypothetical alternatives in 4 choice sets. Modification of traditional conjoint survey in this way enabled us to estimate the factors related to switching cost or switching threshold in addition to the effects of attributes. Also, by using both revealed preference data(1 alternative with current subscription) and stated preference data (4 hypothetical alternatives), additional advantages in terms of the estimation properties and more conservative and realistic forecast, can be achieved. Second, we asked the respondents to choose the most preferred alternative while considering their expected adoption timing or switching timing. Respondents are asked to report their expected adoption or switching timing among 14 half-year points after the introduction of next generation broadcasting services. As a result, for each respondent, 14 observations with 5 alternatives for each period, are obtained, which results in panel-type data. Finally, this panel-type data consisting of $4{\ast}14{\ast}1000=56000$observations is used for estimation of the individual-level consumer adoption model. From the results obtained by empirical application, in case of forecasting the demand of new products without considering existence of previous product(s) and(or) switching cost factors, it is found that overestimated speed of diffusion at introductory stage or distorted predictions can be obtained, and as such, validities of our proposed model in which both existence of previous products and switching cost factors are properly considered, are verified. Also, it is found that proposed model can produce flexible patterns of market evolution depending on the degree of the effects of consumer preferences for the attributes of the alternatives on individual-level state transition, rather than following S-shaped curve assumed a priori. Empirically, it is found that in various scenarios with diverse combinations of prices, IPTV is more likely to take advantageous positions over Digital Cable TV in obtaining subscribers. Meanwhile, despite inferiorities in many technological attributes, Analog Cable TV, which is regarded as previous product in our analysis, is likely to be substituted by new services gradually rather than abruptly thanks to the advantage in low service charge and existence of high switching cost in fixed charged broadcasting service market.

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Estimation of Family Variation and Genetic Parameter for Growth Traits of Pacific Abalone, Haliotis discus hannai on the 3th Generation of Selection (선발 3세대 북방전복의 성장형질에 대한 가계변이 및 유전모수 추정)

  • Park, Jong-Won;Park, Choul-Ji;Lee, Jeong-Ho;Noh, Jae-Koo;Kim, Hyun-Chul;Hwang, In-Joon;Kim, Sung-Yeon
    • The Korean Journal of Malacology
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    • v.29 no.4
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    • pp.325-334
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    • 2013
  • The purpose of this paper is to compare and analyze family variations for growth-related traits of Pacific abalone, Haliotis discus hannai. Genetic parameters and breeding values were estimated using all measurement data like shell length, shell width, and total weight as 18-month-old growth traits of 5,334 individuals of selected third generation's Pacific abalone produced in 2011. Family variations of 865 individuals of the upper 10 families with the largest number were inspected. Overall mean in phenotypic traits of 18-month-old Pacific abalone which was investigated in this study showed 54.5 mm of shell length, 36.8 mm of shell width and 21.3 g of total weight respectively. And, variation coefficient of total weight was 51.0%, so variability of data was shown to be higher than 21.1% of shell length and 20.7% of shell width. The family effects showed significant difference by each family (p < 0.05), and heritability of shell length, shell width, and total weight was medium with 0.370, 0.382, and 0.367 respectively. So it is considered that family selection is more advantageous than individual selection. On the basis of breeding values of estimated shell length and total weight, to investigate distribution and ranking by each individual about the upper 10 families with the largest number of individuals, the values were used by being changed into standardized breeding values. Based on shell length, it was investigated that the individual number of the upper 5.4% is 152 and the number of the lower 5.4% is 8. In case of total weight, it was inspected that the individual number of the upper 5.4% is 164 and the number of the lower 5.4% is 1. Like these, phenotypic and genetic diverse variations between families could be checked. By estimating genetic parameters and breeding values of a population for production of the next generation, if they are used properly in selection and mating, it is considered that more breeding effects can be expected.

A Numerical Model of Three-dimensional Soil Water Distribution for Drip Irrigation Management under Cropped Conditions (작물 흡수를 고려한 3차원 토양수분 분포 모델 개발을 통한 최적 점적 관개 연구)

  • Kwon, Jae-Phil;Kim, Seung-Hyun;Yoo, Sun-Ho;Ro, Hee-Myong
    • Applied Biological Chemistry
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    • v.43 no.2
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    • pp.116-123
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    • 2000
  • A numerical model of three-dimensional soil water distribution for drip irrigation management under cropped conditions was developed using Richards equation in Cartesian coordinates. The model accounts for both seasonal and diurnal changes in evaporation and transpiration, and the growth of plant root and the shape of root zone. Solutions were numerically approximated using the Crank-Nicolson implicit finite difference technique on the block-centered grid system and the Gauss-Seidel elimination in tandem. The model was tested under several conditions to allow the flow rates and configurations of drip emitters vary. In general, simulation results agreed well with experimental results and were as follows. The velocity of soil-water flow decreased drastically with distance from the drip source, and the rate of expansion of the wetted zone decreased rapidly during irrigation. The wetting front of wetted zone from a surface drip emitter traveled farther in vertical direction than in horizontal direction. Under this experimental weather condition, water use efficiency of a drip-irrigated apple field was greatest for 4-drip-emitter system buried at 25 cm, resulting from 10% increase in transpiration but 20% reduction in soil evaporation compared to those for surface 1-drip emitter system. Soil moisture retention curve obtained using disk tension infiltrometer showed significant difference from the curve obtained with pressure plate extractor.

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