• 한국신뢰성학회지:신뢰성응용연구
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• 제18권3호
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• pp.201-207
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• 2018

Purpose: To develop the reliability growth planning for a subsystem of guided weapon system using PM2-Continuous model. Methods: The target MTBF of the subsystem is set by allocating the system target MTBF to the lower level, where ARINC method is applied. Other model parameters such as initial MTBF, management strategy ratio and average fix effectiveness factor are chosen from historical growth parameter estimates. Given the values of model parameters, the reliability growth planning curve using PM2-Continuous model is constructed and the sensitivity analyses are performed for the changes of model parameters. Results: We have developed the reliability growth plan for a subsystem of guided weapon system using PM2-Continuous model. It was found that the smaller the ratio of initial MTBF to target MTBF, the smaller the management strategy ratio, the smaller the average fix effectiveness factor, and the shorter the development test period, the higher reliability growth is required. Conclusion: The result of this study will be used as a basis for establishing the reliability growth plan, the test period setting and the budget appropriation for the similar system entering the system development stage in the future.

• 한국토양비료학회지
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• 제48권5호
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• pp.556-563
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• 2015

Chinese cabbage is one of the most important vegetables in Korea and a target crop for market stabilization as well. Remote sensing has long been used as a tool to extract plant growth, cultivated area and yield information for many crops, but little research has been conducted on Chinese cabbage. This study refers to the derivation of simple Chinese cabbage growth prediction equation by using RapidEye derived vegetation index. Daesan-myeon area in Gochang-gun, Jeollabuk-do, Korea is one of main producing district of Chinese cabbage. RapidEye multi-spectral imagery was taken on the Daesan-myeon five times from early September to late October during the Chinese cabbage growing season. Meanwhile, field reflectance spectra and five plant growth parameters, including plant height (P.H.), plant diameter (P.D.), leaf height (L.H.), leaf length (L.L.) and leaf number (L.N.), were measured for about 20 plants (ten plants per plot) for each ground survey. The normalized difference vegetation index (NDVI) for each of the 20 plants was measured using an active plant growth sensor (Crop $Circle^{TM}$) at the same time. The results of correlation analysis between the vegetation indices and Chinese cabbage growth data showed that NDVI was the most suited for monitoring the L.H. (r=0.958~0.978), L.L. (r=0.950~0.971), P.H. (r=0.887~0.982), P.D. (r=0.855~0.932) and L.N. (r=0.718~0.968). Retrieval equations were developed for estimating Chinese cabbage growth parameters using NDVI. These results obtained using the NDVI is effective provided a basis for establishing retrieval algorithm for the biophysical properties of Chinese cabbage. These results will also be useful in determining the RapidEye multi-spectral imagery necessary to estimate parameters of Chinese cabbage.

• Journal of Animal Science and Technology
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• 제45권6호
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• pp.885-890
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• 2003

본 연구는 재래돼지와 랜드레이스 품종을 기초축으로 조성한 F2 집단의 일령별 체중 자료를 이용하여 비선형 회귀에 의해 추정한 개체별 성장곡선 모수 및 성장 특성치에 대한 LEPR 관련 초위성체 표지인자의 다형성에 따른 효과를 추정함으로써 Leptine 수준에 따른 성장 형질의 특성을 규명하고자 실시하였다. 조사된 F2 집단에 대해 개체별 성숙체중(A)과 성숙률(k)의 평균은 각각 179.69${\pm}$4.40kg 및 0.3103${\pm}$0.0043으로 추정되었으며, 성장 특성에 대한 성의 효과는 통계적 유의성이 없었으며 (p〉.05), 성숙체중(A) 및 최대 증체 속도($\partial$W$_{t1}$/$\partial$t)는 분만 그룹에 따른 유의적인 차이를 보였다(p〈.05). 조사된 모든 성장특성에 대해 LEPR 표지인자의 다형성 효과는 유의적으로 나타났으며(p〈.05), AA 유전자형을 가지는 개체는 만숙성이며, 반면 유전자형이 DD인 경우, 조사된 유전자형들 가운데 초기 성장이 빠른 조숙성의 성장 특성으로 가지지만, 성장률의 증가추세가 일찍 감소하며, 성숙체중의 최대치는 낮을 것을 추정되었다. 따라서 조사된 LEPR 관련 표지인자 유전자형의 다형성에 따른 성장 특성의 해석 및 예측이 가능하며, 그 범위는 생애 전반에 걸쳐 적용해야 할 것으로 사료된다.

• Journal of Animal Science and Technology
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• 제50권5호
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• pp.601-612
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• 2008

본 연구는 한우의 체형과 체중이 일령에 따라 어떻게 변화하며, 선발형질인 도체형질과의 상관 또한 체중 및 체형의 변화에 따라 어떠한 형태로 변화하는지 알아보기 위하여 실시하였다. 분석에 이용한 형질은 체중, 체형 및 도체형질을 포함하여 모두 17가지 형질이며 거세우 161두의 자료를 이용하였다. 성장곡선 추정은 logistic 모형을 이용하였고, 추정한 모수를 토대로 변곡일령 및 변곡일령에서의 특성을 다시 계산하였다. 각 형질에 대한 성장곡선 모수를 분석한 결과 좌골폭은 조숙성, 흉위는 만숙성 형질인 것으로 나타났다. 등지방두께에 대한 흉심, 흉폭 및 요각폭의 순위상관계수는 6~24개월까지 꾸준히 증가하는 반면 다른 체형형질들은 18개월령 이후에 감소하는 것으로 나타났다. 본 연구는 표현형 자료에 대한 분석만이 이뤄졌으나, 한우 성장 단계에 따른 유전적 변화를 살펴보기 위해 유전모수 추정과 같은 추가적인 연구가 이뤄진다면 체형형질을 한우개량에 충분히 이용이 가능할 것으로 생각된다.

• 한국수산과학회지
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• 제29권5호
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• pp.567-577
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• 1996

본 연구는 한국 연근해 갈치의 자원생태학적 특성치인 성장계수와 생잔율, 순간자연 및 어획사망계수, 어획개시연령 및 연령별 성장률을 추정하는 것이다. 갈치의 성장을 나타내는데는 세가지의 성장모델에 적합시켰으며, 이 중 차후의 자원평가연구를 목적으로 von Bertalanffy 성장식을 채택하였다. von Bertalanffy 성장계수는 EXCEL의 Solver를 사용하여 비선형회귀 방법에 의하여 다음과 같이 추정되었다. $L_\infty=46.01cm,\;K=0.3868,\;t_0=-0.3220$. 갈치의 연간생잔율 (S)은 0.277 (분산=0.00035)로 추정되었으며 순간자연사망 계수 (M)는 0.4411년으로 추정되었다. 근년의 순간어획사망계수 (F)는 0.843/년으로서 자연사망보다 어획에 의한 영향이 약 2배나 되고 있음을 암시하였다. 어획개시연령 $(t_c)$은 0.787세로 $50\%$ 성숙연령의다 훨씬 어린 연령이었다 마지막으로 갈치의 연령별 성장률이 추정되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제31권1호
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• pp.26-31
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• 2018

Objective: This study estimated the genetic parameters for body weight gain and growth curve parameter traits in Korean native chicken (KNC). Methods: A total of 585 $F_1$ chickens were used along with 88 of their $F_0$ birds. Body weights were measured every 2 weeks from hatching to 20 weeks of age to measure weight gain at 2-week intervals. For each individual, a logistic growth curve model was fitted to the longitudinal growth dataset to obtain three growth curve parameters (${\alpha}$, asymptotic final body weight; ${\beta}$, inflection point; and ${\gamma}$, constant scale that was proportional to the overall growth rate). Genetic parameters were estimated based on the linear-mixed model using a restricted maximum likelihood method. Results: Heritability estimates of body weight gain traits were low to high (0.057 to 0.458). Heritability estimates for ${\alpha}$, ${\beta}$, and ${\gamma}$ were $0.211{\pm}0.08$, $0.249{\pm}0.09$, and $0.095{\pm}0.06$, respectively. Both genetic and phenotypic correlations between weight gain traits ranged from -0.527 to 0.993. Genetic and phenotypic correlation between the growth curve parameters and weight gain traits ranged from -0.968 to 0.987. Conclusion: Based on the results of this study population, we suggest that the KNC could be used for selective breeding between 6 and 8 weeks of age to enhance the overall genetic improvement of growth traits. After validation of these results in independent studies, these findings will be useful for further optimization of breeding programs for KNC.

• 한국물환경학회지
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• 제24권3호
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• pp.306-310
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• 2008

Characteristics of microalgal growth was investigated using anaerobic effluent from two-phase animal waste digestor as substrate. Batch experiments were carried out to investigate the effect of the initial nitrogen and phosphorus concentrations on growth of Microcystis aeruginosa, Chlorella sp. and Euglena gracilis. In 400 times diluted anaerobic effluent (TN 3 mg/L), single cell growth of the Euglena gracilis population increased twice without delay, although Chlorella sp. and Microcystis aerugenos take over 144 hours. Similar appearance with single cell growth was observed in mixed cultures. However, microalgae population did not increase under condition of 10 times diluted influent (TP 3 mg/L) in both pure and mixed cultures, which was affected by high organic and nitrogen concentration. Logistic growth model successfully fitted to determine biokinetic parameters such as ${\lambda}$: lag time, ${\mu}m$: maximal specific growth rate, A: asymptote of growth.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.614-614
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• 2013

The effect of graphene growth parameters on the number of graphene layers were systematically studied and growth mechanism on copper substrate was proposed. Parameters that could affect the thickness of graphene growth include the pressure in the system, gas flow rate, growth pressure, growth temperature, and cooling rate. We hypothesis that the partial pressure of both the carbon sources and hydrogen gas in the growth process, which is set by the total pressure and the mole fraction of the feedstock, could be the factor that controls the thickness of the graphene. A synthetic method to produce such large area graphene films with precise thickness from mono- to few-layer would be ideal for chemists and physicists to explore the promising electronic applications of these materials. Here, large-area uniform mono-, bi-, and few-layer graphene films were successfully synthesized on copper surface in selective growth windows, with a finely tuned total pressure and $CH_4$/$H_{2gas}$ ratio. Our findings may facilitate both the large-area synthesis of well-controlled graphene features and wide range of applications of graphene.

• 대한치과교정학회지
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• 제47권6호
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• pp.365-374
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• 2017

Objective: The objective of this study is to investigate the eruption pattern and root resorption of the bovine anterior dentition in relation to growth-related parameters based on dental maturity. Methods: A cross-sectional study was conducted on 110 bovine anterior mandibles by using standard radiography, cone-beam computed tomography (CBCT), and actual measurements. We determined the relationships between the stages of dental maturity by using a modification of Demirjian's method and various growth-related parameters, such as the activity of the root-resorbing tissue and mobility of the deciduous teeth. The correlation of growth-related parameters with interdental spacing and distal unusual root resorption (DRR) of the deciduous fourth incisor was assessed. The cause of mesial unusual root resorption (MRR) of the deciduous fourth incisor was determined on the basis of the arrangement of the permanent third incisor. Results: An independent t-test and chi-square test indicated significant differences in growth-related parameters associated with dental arch length discrepancy and factors related to the shedding of deciduous teeth between the low and high dental maturity groups. The samples with interdental spacing and DRR showed a larger sum of mesiodistal permanent crown widths and higher dental maturity than did the respective controls. Samples with MRR tended to show a lingually rotated distal tip of the adjacent tooth crown. Conclusions: Dental maturity has relevance to the interdental spaces and unusual root resorption of mixed dentition. The position of the adjacent tooth crown on CBCT may be correlated with the occurrence of unusual root resorption of the incisor.

• Ocean Science Journal
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• 제41권4호
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• pp.211-219
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• 2006

A comparison was made of population of the economically important cockle Anadara (=Scapharca) broughtoni (Bivalvia, Arcidae) inhabiting different areas of the Razdolnaya River estuary at the head of Amurskii Bay (Peter the Great Gulf, East Sea). Also, changes in cockle population density and structure, as well as in cockle growth rates during the last 20 years were studied. In all years of investigation, the morphometrical parameters and growth rates of cockles were smaller at the sites located close to the River mouth than farther down-estuary. The differences can be attributed to higher concentration of suspended particulate matter, decreased salinity and water temperature, as well as a longer exposure to these unfavorable environmental factors at sites located close to the River mouth, compared to farther sites. For two decades, cockle population density had decreased by almost 30 times at some sites in the River estuary. The main reason for this population decline is commercial over-fishing of the cockle. Besides, for the last 20 years, linear parameters of the cockles in the population decreased approximately by 30% and weight parameters, almost two times. Cockle growth rates also decreased for this period. Evidently, these facts are due to the damaging effect of dredging.