• Advances in aircraft and spacecraft science
• /
• 제1권4호
• /
• pp.409-425
• /
• 2014

Converging flows of a gas and a liquid at a microchannel cross junction, under proper conditions, can result in the formation of periodic, dispersed microslugs. This microslug formation phenomenon has been proposed as the basis for a fuel injection system in a novel, 'discrete' monopropellant microthruster designed for use in next-generation miniaturized satellites. Previous experimental studies demonstrated the ability to generate fuel slugs with characteristics commensurate with the intended application during steady-state operation. In this work, numerical and experimental techniques are used to study the effect of valve actuation on slug characteristics, and the results are used to compare with equivalent steady-state slugs. Computational simulations of a valve with a 1 ms valve-actuation cycle show that as the ratio of the response time of the valve to the fully open time is increased, transient effects can increase slug length by up to 17%. The simulations also demonstrate that the effect of the valve is largely independent of surface tension coefficient, which is the thermophysical parameter most responsible for slug formation characteristics. Flow visualization experiments performed using a miniature valve with a 20 ms response time showed less than a 1% change in the length of slugs formed during the actuation cycle. The results of this study indicate that impulse bit and thrust calculations can discount transient effects for slower valves, but as valve technology improves transient effects may become more significant.

• 한국건설관리학회논문집
• /
• 제13권5호
• /
• pp.25-34
• /
• 2012

본 연구는 주택 후분양제도를 도입한지 6년여 기간이 경과되는 현 시점에서 제도시행의 취지 및 효과를 점검하고, 공급자 관점에서 분양시기에 따른 수익성 변화를 분석하여 그 정도를 파악하였다. 서울시 공동주택 사업을 대상으로 사례분석 하였으며, 분양수입의 현재가치분석, 민감도분석, 분양가를 예측한 현재가치분석을 실시하였다. 분석결과 첫째, 선분양제가 후분양제보다 5.1%~6.2% 수익성이 높았고, 선분양의 4가지 안(착공후 즉시, 건설공정 20%, 40%, 60%) 가운데 착공과 동시에 계약금을 회수하는 안의 분양수입이 가장 높았다. 둘째, 할인율 증가와 분양수입 감소는 정비례하였으며, 할인율이 커질수록 공급자관점에서의 분양수입은 감소하였다. 셋째, 분양시기에 따른 분양가격 변동을 감안하여, 기본형건축비의 변동폭을 고려한 분양수입의 현재가치는 선분양방식이 후분양방식에 비해 2% 내외의 미미한 수준에서 다소 높았다. 본 연구는 분양시기에 따른 수익성을 공급자 관점에서 명확하게 계량화하여 제시하였고, 분양시기 변화에 따른 분양가 변동을 고려하여 분양수입을 산출하였다는 점에 의의가 있다.

• 한국경영과학회지
• /
• 제20권1호
• /
• pp.55-62
• /
• 1995

This paper compares the two policies which are unsed in Korean electronic appliance industry. Policy I is a general warranty policy under which all of failures during warrenty period (12 months) are repaired without charge. Policy II was proposed recently by a company. Under Policy II, when the product fails until a certain times(6 months), the failed product will be replaced by the new product and all other failures from the certain time to the warrenty period (24 months) will be repaired free. We obtain the expected total warranty costs per product and necessary conditions under which the Policy II has a meaning in economic point of view without or with discount rate. Some numericla examples are considered.

• 한국유통학회:학술대회논문집
• /
• 한국유통학회 2000년도 추계학술대회 발표논문집
• /
• pp.91-105
• /
• 2000

Results of a study of the coordination effect in stocking and promotional markdown policies for a supply chain consisting of a retailer and a discount outlet (DCO) are reported here. We assume that the products are sold in two consecutive periods: Normal Sales Period (NSP) and subsequent Promotional Sales Period (PSP). When managers in the two periods coordinate, they share information on the demand forecast and jointly decide the stocking quantity, markdown time schedule, and markdown price to maximize mutual profit. In the absence of coordination, decisions are decentralized to optimize the individual party's objective function. Optimal coordination policy for the retailer/DCO problem setting is analyzed, and the coordination policy is compared with the uncoordinated policy to explore factors that make coordination an effective approach.

• 한국의류학회지
• /
• 제32권8호
• /
• pp.1233-1243
• /
• 2008

This study examined return policies of the Korean retailers and their differences by retail format. Return policies of 363 retailers including dept stores, discount stores, brand consignment stores, small shops, outlet stores, TV home shopping companies, and internet shopping malls were collected. Acceptance of refund or/and exchange, return grace period, and return requirements or restrictions of each retailer were analyzed. The results showed that most retail formats except small shops and internet shopping malls allowed refund. The seven day return grace period was most common though large retail chains allowed more generous time frames and small shops allowed shorter dates. Restrictions for return varied by retailers and retail formats. Generally retailers followed the guidelines of consumer protection laws. The study discussed implications of return policy analysis.

• 한국산업정보학회:학술대회논문집
• /
• 한국산업정보학회 2006년도 춘계 국제학술대회 논문집
• /
• pp.235-240
• /
• 2006

The existing inventory managements bear a relation to forecasting or assumptions. So these methods become more complicated and more expensive systems as time goes. This paper developed a practical inventory system which is called DCC(demand control chart). DCC does not 'forecast' but 'control' the trend of demand without assumptions. According to the trend of sales, DCC adjusts an order quantity considering the capacity of shelf in a store. Specially, DCC is a useful method under FRID system. Besides, this paper introduces EPFR(Every Period Full Replenishment) policy for reducing stocks.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2005년도 추계학술대회 논문집
• /
• pp.1287-1292
• /
• 2005

With opening of KTX, Korea Railway have carried out a variety of marketing strategies unprecedented, which have brought successful results for dramatical increasing passengers in KTX from 72 thousand passengers per day in 2004 to 85 thousand passengers per day in 2005. These marketing strategies for Korea Rail to use in increasing passengers for KTX are the following: special discount fare system for non-season to penetrate into transport market in the first time, fare system reform considering to customers' willing to pay, new item development by each specific market like contracting transport, YMS(Yield Management System) by stages, Home-ticket-and-e-ticket and tele-marketing service, and wide range covering sales network making it comfortable for users in KTX. This paper discusses these successful marketing strategies and its performance and finally suggests strategic implications for KTX growth.

• 한국조리학회지
• /
• 제7권2호
• /
• pp.243-266
• /
• 2001

In order to attain the research objective which it sees with method of research the literature research which investigates an existing system with triangular position of one concept the relationship literature, a statistical data and information back from data analysis it arranged the data which is necessary in foundation, it applied. Travel ep with direct conversation investigation of the person in charge and experience of the researcher it accomplished a research with character during that time. The research result with afterwords provides a same current events point First. It is a diversification of marketing. Secondth. It is an exhibition and exhibition travel goods wool visitor concentrating. Thirdth. It attempts a travel agency merger anger. Fourthth, goods reservation it sleeps and the pro wool of the on-line travel agency against syen it is. Fifth. Advance reservation discount my execution or it is a customer objective card my introduction. Sixth. Must promote an individual travel goods development and an order travel goods development.

• 복식문화연구
• /
• 제10권6호
• /
• pp.666-679
• /
• 2002

The purpose of the present study was to analyze clothing shopping orientation and impulsive purchase behavior for clothing by using adolescents. Data were collected through a self-administered questionnaire survey from 680 middle and high school students living in Gangrung area from July 2 to July 6, 2001; 582 were used for the data analysis. Data were analyzed by chi-square analysis, 1-test, ANOVA, descriptive statistics, cluster analysis and Duncan's multiple range test. The results showed significant differences in clothing shopping orientation and in the impulsive shopping factors for clothing among the groups determined by demographic characteristics and, in the impulsive shopping factors for clothing among groups determined by the shopping orientation. Female students and high school students showed higher tendencies of recent experiences of impulsive buying for clothing. More thin half of the subjects tended to spend less than 30,000 won and to buy two items each time when purchasing clothing impulsively. Most students used discount shops or specialized stores fur impulsive purchase.

• Asia pacific journal of information systems
• /
• 제23권4호
• /
• pp.85-102
• /
• 2013

This study proposes a web presence readiness model based on pre-payment service functions and a post-payment service function both of which embrace the major concerns of customers in the online purchasing context. Based on the concept of customer utility from the product itself and instrumental utility, the research model suggests four antecedents including, Perceived Economic Benefits, Product Search Support Quality, e-Shopping Method Diversity, and Post-Payment Support Quality. We empirically examined a proposed research model using data collected from online rating company websites. Among the four antecedents, post payment support quality is found to be the most influential determinant of customer evaluation on e-commerce websites. Based on the empirical results, the current study proposes an alternate model of web presence readiness. The findings of this study may provide an insight to field practitioners designing commercial websites. The implications and future research directions are further discussed.