• 산경연구논집
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• 제12권8호
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• pp.33-39
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• 2021

Purpose: The influence of age on time preference is not identified in the usual cross-sectional analysis. This study aims to test whether age affects time preference after controlling for the effects of individual heterogeneity including cohort effects. Research design, data and methodology: Drawing on a nationally representative panel dataset of Indonesians, we estimate the effects of age on time preference after controlling for unobserved individual heterogeneity as well as potential cohort effects. We measure time preference exploiting information on two sets of multiple price lists: one for a one-year delay, and the other for a five-year delay. Results: When we controlled for time-invariant individual characteristics, including birth cohort effects in a fixed effects model, the older men and women were more patient in a linear fashion, particularly when the delay was longer. To highlight the importance of controlling for individual fixed effects, we repeated the specification without controlling for individual fixed effects in OLS or censored maximum likelihood regression; we found no relation between age and impatience in men or women and for a one or five-year delay. Conclusions: The older men and women are more patient, and time preferences are correlated with unobserved individual heterogeneity.

• East Asian Economic Review
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• 제27권3호
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• pp.179-211
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• 2023

This paper investigates the relationship between the spread of COVID-19 and time preference. In contrast to previous studies that compared time preferences before and during the pandemic, this study estimates time preferences during the COVID-19 period using eight surveys conducted over two years. Additionally, a regression analysis was conducted on the number of new COVID-19 cases and the time elapsed since the outbreak, with estimated time preference as the dependent variable. Despite a small sample size, statistically significant results were obtained, showing that as the number of new cases increased, time preference also increased. However, this effect diminished over time and disappeared by the end of 2021 in Japan. This may be due to the public's growing familiarity with the risks of COVID-19 and the availability of vaccines and treatments. Despite a significant increase in new cases in 2022, time preference was lower than immediately after the outbreak, and this was reflected in private investments. Immediately after the outbreak of COVID-19, private investments decreased by 12% compared to the previous year, but the investments are returning in 2022 despite the surge in the number of cases. The trend of time preference explains the trend of Japanese private investments very well.

• The Korean Journal of Physiology
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• 제1권1호
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• pp.121-130
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• 1967

Determination of weekly and daily energy expenditure was made on 62 Republic of Korea Army cadets who were selected at random in order to estimate the weekly and daily ealorie expenditure. Basal metabolic rate (B.M.R.), and energy cost of various military and daily activities were measured by indirect calorimetry using open circuit method. Time-motion studies were also carried on using a stop-watch. The total weekly energy expenditure was calculated by summation of data using energy cost per minute, and the time spent on each activity. Determination of daily energy expenditure was deduced from each data of weekly energy expenditure. Food survey was also carried on for a week, and daily calorie intake was determined by a weekly average discounting loss in cooking. All measurements were determined from the Standard Table of Food Composition published by the Ministry of National Defense (1961). Following data were observed. 1. Physical status of cadets are as follows. Please note that the height and weight averages are 1-2cm and 4-5kg respectively over that of the Seoul National University students. First year Height 167.92 cm $(S.D.{\pm}4.09)$ Weight 61.72 kg $(S.D.{\pm}4.53)$ Second year Height 167.89 cm $(S.D.{\pm}3.46)$ Weight 63.01 kg $(S.D.{\pm}4.61)$ Third year Height 168.15 cm $(S.D.{\pm}4.24)$ Weight 43.48 kg $(S.D.{\pm}5.03)$ Fourth year Height 168.10 cm $(S.D.{\pm}3.70)$ Weight 64.02kg $(S.D.{\pm}5.10)$ 2. The B.M.R. of cadets averaged $36.57\;Cal./m^2/hr.(S.D.{\pm}3.63\;Cal./m^2/hr.)$ is almost equal with data on the same ages of civilians and the Japanese, but a lower average of $5.1\;Cal./m^2/hr.$ than that of a common soldier. 3. The energy expenditure during various military activities is close agreement with Consolazio. Passmore and Durnin, and Japanese reports.

• 대한예방한의학회지
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• 제3권2호
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• pp.1-23
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• 1999

The purpose of this paper is to survey the current status of service utilization in oriental medicine, to identify the determinants of consumers' decision in the service utilization, and then suggest policy implications for promoting the consumers' utilization. A multiple regression model was adopted to analyze the factors that influence consumer's decision in purchasing the oriental medical services. Data used in this research relied on National Survey Data conducted by Korea Institute of Health and Social Affairs, and sampling survey. The results could be summarized as follows.: 1. the number of visits to oriental medical institutions has shown an overall increase during the last decade since the inception of health insurance for oriental medical services. It still, however, revealed a relatively iow figure to western medical services. 2. the main factors, after controlling demographic variables, that determine consumers' selection between oriental medical services and western medical services are considered to be price, belief in effectiveness of services, waiting time for service. Implications for policy recommendation include 1. to reduce a barrier to service utilization by discounting dramatically the price of herb medicine, which is believed to be crucial in expanding market share, 2. to encourage consumer's belief in clinical effectiveness through a specialization in competitive services compared with wertern medicine, 3. to keep the affirmative image among consumers alive through an active participation of oriental medical doctors in community activities, 4 to change the health care system in favor of oriental medicine in the long run.

• 대한토목학회논문집
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• 제38권5호
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• pp.703-711
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• 2018

최근 다양한 도시철도 노선이 건설되고, 주변노선과 연계가 이루어짐에 따라 도시철도 이용률이 증가하고 있다. 하지만, 정부는 여전히 기존의 획일적인 운임정책을 고수하고 있어, 다양한 이용패턴에 체계적인 대응을 하지 못할 뿐만 아니라, 공공성 위주의 운임정책으로 인해 운영사의 수익성 악화라는 구조적 문제점이 발생하고 있다. 본 연구는 도시철도 운임정책의 합리성을 제고하기 위해 일본, 영국 등 주요 선진국의 도시철도 운임정책을 검토하였다. 운임정책에 대한 체계적인 분석을 위해 운임결정방식, 카드운임에 대한 할인제도, 운임구조, 그리고 정부 보조금 정책 등의 관점에서 살펴보았으며, 이를 토대로 대한민국 수도권 도시철도 운임정책의 문제점 및 개선방안을 도출하였다. 본 연구를 통해 도시철도 서비스 수준과 수익성에 부합하는 적정 요금정책을 수립하여 합리적인 도시철도 운영에 도움을 줄 수 있을 것으로 기대한다.

• 농업과학연구
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• 제29권1호
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• pp.55-65
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• 2002

The most representative fruit in Yanbian area is Applepear(Ping Guo Li). It has been a important resource of farm income. According to the economic growth and income Increase of individual consumers, food consumption pattern will be changed from grain to high value cash crops such as Applepear and vegetables. The globalization and adapt ion of free market oriented economic policy of China government have led to change the collective farming system to individual farm management system. The institutional transformation have brought about high productivity of farm products and incomes of farmers. Therefore the plantation area of Applepear and requirement of investment cost for establishment of Applepear farms have increased rapidly since the 1980's, the time of perestroika and glasnost in Chinese economy. In prosperity of Chinese agriculture, individual farmer's decision making as free selection of farmland use, selection of high pay-off crops, free sale of the products in free market and credit support for the project might be the most important factors. In case of Applepear farm development, net present value of the project net benefit was estimated at 55.518won per hectare and financial rate of return was 21%. The benefit/cost ratio of the project was 2.11. Considering 10% of discounting rate or the opportunity cost of capital in China the Applepear farm development project showed us economically feasible in the light of the above efficiency indices. The Chinese government has to support Applepear farm development project financially and institutionally considering the high-payoff benefit of the fruit and farmer's in come increase in the future.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 1995년도 추계학술강연 및 발표대회 강연 및 발표논문 초록집
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• pp.25-25
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• 1995

Liquid phase sintering of 90W-6Ni-4Mn alloy has been investigated as functions of sintering atmosphere, heating rate, and reduction temperature. The present work accounts for the thermodynamic oxidatiodreduction reactions of constituent powders of W, Ni and Mn. By discounting these reactions, the previous investigations would obtain only the alloy with large pores and the lowered relative sintered density, by the liquid phase sintering under a dry hydrogen atmosphere. the sintering cycle consisted of a rapid heating to reduction temperatures under high purity nitrogen atmosphere, and holding for 4 hours and sintering at $1260^{\circ}C$ for 1 hour under a dry hydrogen gas. The relative density of the sintered alloy increased with increasing heating rate. As the reduction temperature increased, the relative density increased to the lm theotical density at the duction temture above $1150^{\circ}C$. The mimsturcatre of sintered alloys has been analysed by a scanning election microscope. The sintered density was compared with those obtained from the other investigators. It was found that the reduction $1150^{\circ}C$ results in the lowered densification of 90W-6Ni-4Mn alloy. This is caused by the fact that reducing reactions of W and Ni oxides contained in W an Ni powders concomitantly leads to oxidizing reaction of Mn powder the oxidized Mn is hardly reduced at sintering temperature and thereby remains large pores in the alloy. It is concluded that the W-Ni-Mn alloy with full density can be obtained by the precise control of atmosphere, heating rate, and sintering temperature.

• 한국도로학회논문집
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• 제11권1호
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• pp.47-58
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• 2009

요금을 지불하게 되는 유료도로에 대해서는 별도의 가중치를 산정하여 교통계획 모형 내에서 모델링 할 수 있도록 해야 하나 현존하는 유료도로의 가중치 산정방법에서 발생하는 문제점은 현실과 유사한 통행패턴을 설명하기에 부적당하다. 본 연구는 국가교통DB센터에서 이미 정산된 가중치, 차종별 시간가치를 적용한 가중치 그리고 차로수별 교통량 비율로 수정된 가중치로서 총 세 개의 대안을 선정하여 비교 분석하였다. 그 결과 국가교통DB센터에서 정산되어 차로수의 구분없이 동일한 가중치를 적용하였을 경우에는 허용오차범위 내에 포함된 샘플수가 다른 시나리오에 비해 비교적 다수 포함되었으나 현재 유료도로의 차로수별 할인율과 할증률을 반영하지 않고 정산되었다는 점에서 현실에 맞지 않는 방법론으로 분석되었다. 또한 차종별 시간가치를 이용한 가중치는 현재 적용되는 가중치 중에서 가장 이론적으로 정립되었다고 할 수 있으나 가중치의 비율이 낮게 적용됨으로서 배정교통량이 과다예측 되는 결과로 나타났다. 그러나 차종별 시간가치와 차로수별 교통량 비율을 합산하여 재 산정한 가중치를 적용한 결과는 세 개의 대안 중 가장 현실에 근접한 통행배정 결과로 분석되었다. 또한 통행배정 방법에 있어 총량OD평형배정방법이 PCU통행배정방법보다 현실에 가까운 배정결과가 나타나는 것으로 나타났다.

• Biomolecules & Therapeutics
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• 제27권4호
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• pp.349-356
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• 2019

Behavioral analysis in mice provided important contributions in helping understand and treat numerous neurobehavioral and neuropsychiatric disorders. The behavioral performance of animals and humans is widely different among individuals but the neurobehavioral mechanism of the innate difference is seldom investigated. Many neurologic conditions share comorbid symptoms that may have common pathophysiology and therapeutic strategy. The forced swim test (FST) has been commonly used to evaluate the "antidepressant" properties of drugs yet the individual difference analysis of this test was left scantly investigated along with the possible connection among other behavioral domains. This study conducted an FST-screening in outbred CD-1 male mice and segregated them into three groups: high performers (HP) or the active swimmers, middle performers (MP), and low performers (LP) or floaters. After which, a series of behavioral experiments were performed to measure their behavioral responses in the open field, elevated plus maze, Y maze, three-chamber social assay, novel object recognition, delay discounting task, and cliff avoidance reaction. The behavioral tests battery revealed that the three groups displayed seemingly correlated differences in locomotor activity and novel object recognition but not in other behaviors. This study suggests that the HP group in FST has higher locomotor activity and novelty-seeking tendencies compared to the other groups. These results may have important implications in creating behavior database in animal models that could be used for predicting interconnections of various behavioral domains, which eventually helps to understand the neurobiological mechanism controlling the behaviors in individual subjects.

• 한국산업정보학회논문지
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• 제27권2호
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• pp.83-100
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• 2022

마케팅분야에서는 제품 상징주의를 지닌 쾌락적 소비에 관한 주제와 관련된 개념적 연구는 상징적 소비주의와 쾌락적 경험연구에 공헌하였다. 예상치 못한 소득이나 일시적 이득에 대한 기대를 소비자가 어떻게 다루는가를 연구하는 것은 그들이 경험을 즐기는데 무엇이 영향을 미치는 가를 이해하는데 도움을 줄 것이다. 이 논문은 쾌락적 소비와 실용적 소비의 상반관계를 논의한다. 일시소득이 발생한 상황에서 언제 왜 소비자들이 쾌락적 혹은 실용적 제품을 선택하는 가를 알아보는 것이 목적이다. 우리는 5개의 가설을 제시하고 일련의 실험을 통해 복권금액이 증가할 때 응답자들은 실용제품보다 쾌락제품을 선호하고, 취득확률은 두 제품간 차이가 없고, 선호순위도 차별화되지 않았다. 일시소득이 증가할 때 두 제품간의 선호그래프는 반대로 나타났다. 할인율이 변할 때 소비자의 선호순서는 변활 것으로 예상된다. 응답자들은 쾌락제품을 가장 선호하고, 실용제품, 할인 현금 순으로 선택하였다. 따라서 소비자의 쾌락주의와 쾌락적 경험에 대한 환상을 자극하는 것은 효과적인 마케팅 전략과 전술이 될 것이다.