• 산업경영시스템학회지
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• 제37권1호
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• pp.165-171
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• 2014

We develop an optimization algorithm for a periodic review inventory system under a stochastic budget constraint. While most conventional studies on the periodic review inventory system consider a simple budget limit in terms of the inventory investment being less than a fixed budget, this study adopts more realistic assumption in that purchasing costs are paid at the time an order is arrived. Therefore, probability is employed to express the budget constraint. That is, the probability of total inventory investment to be less than budget must be greater than a certain value assuming that purchasing costs are paid at the time an order is arrived. We express the budget constraint in terms of the Lagrange multiplier and suggest a numerical method to obtain optional values of the cycle time and the safety factor to the system. We also perform the sensitivity analysis in order to investigate the dependence of important quantities on the budget constraint. We find that, as the amount of budget increases, the cycle time and the average inventory level increase, whereas the Lagrange multiplier decreases. In addition, as budget increases, the safety factor increases and reaches to a certain level. In particular, we derive the condition for the maximum safety factor.

• 농촌계획
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• 제17권1호
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• pp.13-27
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• 2011

This study analyzed the budget investment plans for the unit-project items(UPI) of 176 project districts for the rural village comprehensive development projects (RVCDP). This study classified the master plan reports of 176 project districts into 88 unit project items in aspect of project management, in order to analyze characteristics of distribution of budget in each project item. Most of all unit project items have similar types of uniform distribution with plus skewness in frequency pattern analysis except the total budget of the project district. This study analyzed the characteristics of budget distribution per province, year, and geographical types of region. Furthermore this paper also analyzed ratio of budget in unit project items to find out distribution pattern of each budget between project items over time. The hierarchical system for UPI of RVCDP consisted of three steps, which are 4 items of the first step on Strength of Rural-urban Exchange & Regional Capability (RURC), Green-income Infrastructure & Facility (GIF), Culture- health-welfare Facility, and Eco-environment & Landscape facility (ELF), 13 items for the second one, and 52 items for the third project items. From the results of the budget investment analysis for 5 years from 2004 to 2008, the budget investment ratios of RURC and ELF have steady state for every year, while GIF in decreasing and ELF in increasing over time. The ratios of UPI on infrastructure were decreased, whereas those on culture, health, and welfare were increased. Portion of tow project items among 52 items, which are community centers for village residents and rural experimental study facility, has 30% of total budget investment. Futhermore, the budget ratios of seven project items showed 50% of total budget. Average value of project budgets for five years was optimized as a type of exponential function in the case of decent array for ranking order.

• The Korean Journal of Ecology
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• 제26권1호
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• pp.1-4
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• 2003

해오라기의 번식기 일주행동 중 activity budget은 수컷의 경우, 서기 29.5%, 깃털다듬기 21.5%, 편한행동 10.9%의 순이었고, 암컷은 휴식 26.3%, 둥지유지·보수 18.4%, 깃털다듬기 15.3%로서 암컷과 수컷사이에 고도의 유의차가 나타났다(p<0.01). Activity-time budget은 수컷의 경우 서기 38.7%, 이동 33.5%, 깃털다듬기 11.5%로 나타났고 암컷은 휴식 55.4%, 서기 18.4%, 깃털다듬기 9.4%로서 암컷과 수컷사이에는 고도의 유의차가 있었다(p<0.01). 번식시기에 있어서 암·수의 activity budget을 살펴보면, 수컷은 번식기동안 서기와 깃털다듬기가 전체행동의 약 50%를 차지하였다. 그러나 암컷은 짝짓기시기부터 부화기까지 휴식과 둥지유지·보수가 50%이상을 차지하였지만 육추기 I부터는 휴식과 둥지유지·보수가 급감하고 서기가 증가하였다. Activity-time budget에서 수컷은 포란기 Ⅱ 까지는 서기가 증가하였지만 부화기부터는 서기가 감소하고 이동이 증가하였다. 암컷은 산란기부터 부화기까지 휴식이 80% 이상을 차지하였으나, 이후에는 이들이 감소하고, 서기가 급격히 증가하였다.

• 산업공학
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• 제24권4호
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• pp.295-303
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• 2011

This paper presents a discrete time optimal asset buying problem with a predetermined final deadline where an available budget is limited. A cost is paid to search for assets called the search cost. A seller who shows up offers a price for the asset and then the buyer decides whether or not to buy the asset by comparing the offered price to his optimal selection threshold. When the budget becomes less than the search cost or the price of the asset the buyer can get a necessary loan with some interests. We clarify the properties of the buyer's optimal selection threshold in order to maximize the expected value of budget which is left after paying all the search costs and the price of the asset at that point in time.

• Journal of Ecology and Environment
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• 제43권2호
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• pp.263-270
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• 2019

Background: The gelada baboon, Theropithecus gelada Ruppell, 1835, is an endemic primate of the central and western highlands of Ethiopia occurring between altitudes of 1800-4400 m. Variability in activity time budget between the two gelada social units, i.e., one-male units (OMUs) and all-male units (AMUs), has not been studied previously. Thus, the present study was an effort to understand intra- and inter-variations in group size and daily activity time budget in gelada baboon OMUs and AMUs at Guassa Community Conservation Area, Central Ethiopia. The instantaneous sampling method was used in the data collection. Results: Both OMU and AMU groups allocated more time for feeding (OMUs = 36.96%; AMUs = 35%) followed by moving (OMU = 25.8%; AMUs = 27%). Grooming was the most frequent social activity in both family groups (OMUs = 8.56%; AMUs = 11.81%). OMUs and AMUs did not show significant variation between themselves in the time budget and temporal distribution of their daily activities. However, the overall variation in the time budget allocated for daily activities within OMUs and AMUs was statistically significant (p < 0.05%). The different age and sex groups in OMUs (i.e., immature, sub-adult females, subordinate males, adult females, and alpha males) showed statistically significant variation in their time budget allocation for the daily activities (p < 0.05) except for feeding and moving. Alpha males had the highest proportion of resting (32.14%) and aggression (31.92%). Immature individuals were responsible for > 90% of the time budget recorded for playing while adult females showed the highest frequency of grooming. Group size of OMUs ranged between 5 and 15 individuals (mean ± SD = 11.25 ± 1.95). Adult females comprised the highest number within OMUs (mean = 4.5) followed by immature individuals (mean = 3). The group size of AMUs ranged from 4 to 8 (mean ± SD = 6.6 ± 1.5). Conclusion: Our results showed that the gelada baboon spent less time on foraging compared to previous studies at the Simien Mountains and Debre-Libanos area. We suggested this variation could be explained based on higher forage quality at Guassa Community Conservation Area resulting from better conservation of the habitat.

• 한국도로학회논문집
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• 제11권3호
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• pp.13-21
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• 2009

사회 경제적 변화에 따라 통행자 패턴은 상당한 변화를 가져왔다. 통행자 패턴 중 통행시간은 통행자에게 제한된 자원에 해당한다. 통행자들은 이 제한된 자원을 자신의 활동에 적절히 투입하여 효용을 극대화 하려고 한다. 즉 통행에 대해서 지불 할 수 있는 혹은 개인의 효용극대화를 위해 선택할 수 있는 고유의 통행시간예산을 가지고 통행한다. 본 연구는"2002년 가구통행실태조사"에서 수집된 통행자 특성 변수들을 토대로 상호관련성 및 특성분류가 가능한 CART 분석방법을 이용하여 통행시간예산에 영향을 미치는 특정 요인에 대한 그룹화 및 추출화를 수행하며, 그에 따른 통행자 통행시간예산 추정 모형을 도출하고자 하였다. CART 분석 결과, 통행시간예산에 영향을 미치는 요인으로는 나이, 주택규모, 주택종류, 고용형태, 직업, 세대주 관계 등으로 나타났고, 도출된 영향요인들의 특성을 고려하여 추정모형을 개발하였으며, 그 결과 나이, 주택규모, 주택종류가 전반적으로 양(+)의 영향을 미치는 것으로 나타났다, 고용형태에서 상대적으로 통행의 빈도가 낮은 재택근무가 음(-)의 값으로 나타났다. 특히, 직업의 경우 주부 무직 미취학아동과 농업 어업 수산업에 종사하는 사람이 음(-)의 값을, 행정 사무 관리직이 양(+)의 값을 가지는 것으로 나타났다.

• Animal Bioscience
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• 제37권5호
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• pp.944-951
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• 2024

Objective: Parturition is crucial for dams, their calves, and cow managers. The prediction of calving time, which assists cow managers to decide on the relocation of cows to maternity pens and necessity of human supervision, is a pivotal aspect of livestock farming. However, existing methods of predicting calving time in dairy cows based on hormonal changes and clinical symptoms are time-consuming and yield unreliable predictions. Accordingly, we investigated whether heart rate variability (HRV) which is a non-invasive assessment of autonomic nervous system (ANS) activity and behavior during the prepartum period would be useful for predicting calving time in dairy cows. Methods: Eight pregnant cows were surveilled under electrocardiogram and video recordings for HRV and behavioral analyses, respectively. HRV parameters in time and frequency domains were evaluated. A 24-h time budget was calculated for each of six types of behavior (standing and lying with or without rumination, sleeping, and eating). Results: Heart rate on calving day is considerably higher than those recorded on the days preceding calving. Low frequency power declined, whereas high frequency power escalated on the calving day compared to the period between 24 and 48 h before calving. The time budget for ruminating while lying decreased and that while standing increased markedly on the calving day compared to those allocated on the preceding days; nonetheless, the total time budget for ruminating did not differ during the prepartum period. Conclusion: We elucidated the ANS activity and behavioral profiles during prepartum period. Our results confirm that HRV parameters and behavior are useful for predicting calving time, and interestingly indicate that the time budget for ruminating while standing (or lying) may serve as a valuable predictor of calving. Collectively, our findings lay the foundation for future investigations to determine other potential predictors and formulate an algorithm for predicting calving time.

• 문화기술의 융합
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• 제9권6호
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• pp.779-787
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• 2023

예산 분석에 관한 기존 연구는 이론적 배경 없이 전체 예산 대비 국방예산의 연간 변화만을 기술하는 데 대부분 국한되어 왔다. 본 연구에서는 단절균형이론(Punctuated Equilibrium Theory, PET)을 이용하여 국방비 지출에 대한 실증분석을 실시하였다. 본 연구의 목적은 한국의 국방예산(총예산, 전력운용예산, 방위력개선예산)의 추이를 살펴보고, 단절균형이론을 사용하여 국방예산의 급진적 변화 지점을 파악하고 분석하는 것이다. 본 연구에서는 또한 1998년부터 2017년까지 매년 대한민국 국방예산 자료를 활용하여 국방예산의 추세와 급격한 변화 지점을 탐색하였다. 그 결과, 1998년부터 2017년까지 한국의 국방비 지출 패턴은 다음과 같은 특징을 갖는 것으로 나타났다. 국방예산 총액 기준 19년간 안정적인 성장을 보였고 일회성 단절지점(5.0%)을 보였으며, 전력운영비는 18년 동안은 균형을 이루며 안정적으로 성장하였고 두 번의 단절지점(10%)을 보였다. 방위력개선비는 총 5번의 급격하게 변화는 단절지점을 확인할 수 있었다.

• The Journal of Asian Finance, Economics and Business
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• 제8권3호
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• pp.741-750
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• 2021

The budget deficit is closely related to expansionary fiscal policy as a fiscal instrument to encourage economic growth. This study aims to apply optimal control theory in the Keynesian macroeconomic model for the economy, so that optimal growth can be found. Macroeconomic variables include GDP, consumption, investment, exports, imports, and budget deficit as control variables. This study uses secondary data in the form of time series, the time period 1990 to 2018. Performing optimal control will result in optimal fiscal policy. The optimal determination is done through simulation, for the period 2019-2023. The discrete optimal control problem is to minimize the objective function in the form of a quadratic function against the deviation of the state variable and control variable from the target value and the optimal value. Meanwhile, the constraint is Keynes' macroeconomic model. The results showed that the optimal value of macroeconomic variables has a deviation from the target values consisting of: consumption, investment, exports, imports, GDP, and budget deficit. The largest deviation from the average during the simulation occurs in GDP, followed by investment, exports, and the budget deficit. Meanwhile, the lowest average deviation is found in imports.

• 한국의류산업학회지
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• 제7권6호
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• pp.624-632
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• 2005

The purpose of this study was to examine the consumers' purchasing behavior of budget-priced cosmetics according to the shopping orientation. Questionnaires used for this study were composed of 57 questions including 21 questions about cosmetic shopping orientation, 32 questions about budget-priced cosmetic purchasing behavior and four questions about demographic variables. Questionnaires were administrated to 20 to 49 aged 317 women who have shopping experience on budget-priced cosmetics. Data were analyzed by using factor analysis, cluster analysis, ANOVA, ${\chi}^2$-test, correlation, crosstabulation analysis, and scheffe test utilizing SPSS/WIN. The results were as follows. First, shopping orientation of cosmetics were classified into 5 factors: 'interest and impulsive purchasing tendency', 'price-oriented purchasing tendency', 'ration-oriented purchasing tendency', 'famous brand-oriented purchasing tendency' and 'brand royalty- oriented purchasing tendency'. According to the shopping orientation of cosmetics, the respondents were classified into 4 groups: 'passive shopping group', 'rational shopping group', 'active shopping group', 'neutral shopping group'. Second, when comparing each group's purchasing behavior of budget-priced cosmetics with shopping orientation of cosmetics, there was not significant difference in one time purchasing cost and the number of shop visits. In case of demographic variables concerning purchasing behavior of budget-priced cosmetics, there was significant differences in one time purchasing cost according to age, level of education and employment status. The number of shop visits had also difference according to age, level of education and monthly family income. Based on these results, marketing strategies for demographic characteristics of target market rather than the shopping orientation are needed.