• 한국항만경제학회지
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• 제37권2호
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• pp.73-89
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• 2021

핸디사이즈 벌크선 시장은 중대형 선박으로 운송이 불가능한 다양한 화물을 운송할 수 있으며, Spot용·대선 시장이 활성화 되어 있고 중대형 벌크선과 독립적인 성격의 시장으로 단기간에 변화하는 시황 및 용선료 변동성에 의한 위험이 보다 많은 시장이다. 본 연구에서는 부정기 벌크선 선형에서 핸디사이즈 운임지수(BHSI)와 Spot용선료에 영향을 미치는 요인들을 검정하고 요인들의 과거 값을 이용하여 종속변수의 동태적 반응을 파악 및 단기 예측을 위하여 벡터자기회귀모형(VAR)을 이용하여 분석을 하였다. 인과성 검정 결과 핸디사이즈의 주요 선적 화물인 원료탄, 일본후판, 열연강판의 가격과 선복량, 선박유가와 인과관계가 나타났으며, VAR모형의 적정시차와 안정성을 확인 후 충격반응함수와 예측오차분해분석을 실시하였다. 충격반응함수 분석 결과 원료탄 가격, 열연강판 가격, 선박유가 3가지 변수는 신뢰구간 상한과 하한이 모두 같은 구간으로 유의하다고 나타났으며, 열연강판 가격의 충격이 가장 유의한 영향을 미치는 것으로 확인되었다. 운임지수(BHSI)와 Spot용선료 두 종속변수 모두 거의 동일한 결과로 나타났으며 t시점에서 발생한 원료탄가격의 표준편차 1단위의 충격에 양(+)의 영향, 열연강판 가격의 충격에 양(+)의 영향, 선박유가의 충격에는 음(-)의 영향의 결과를 보였다. 예측오차 분산분해분석 결과 운임지수(BHSI)와 Spot용선료에 영향을 미치는 설명력은 열연강판 가격, 원료탄 가격, 선박유가, 일본후판 가격, 선복량 순으로 동일하게 나타났으며 열연강판 가격의 설명력은 3기부터 점차 상승하여 운임지수에는 30%, Spot용선료에는 26%까지 영향을 미친다고 나타났다. 기존 선행연구와 차별화하여 단기적인 시차 영향을 알아보기 위해 주요 선적화물의 월간 가격 데이터를 사용하여 분석을 수행하였으며, 월 단위 시황 예측이 가능한 유의미한 결과를 도출하였다. 이 연구가 핸디사이즈 선박을 운항하는 선사와 핸디사이즈 용·대선 시장 관계자들에게 단기적인 시황 예측에 도움이 될 수 있다는데 의의가 있다고 생각한다.

• Journal of Korea Trade
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• 제23권5호
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• pp.87-101
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• 2019

Purpose - This paper examines the effectiveness of the foreign exchange risk insurance system in the promotion of SME exports in Korea. The purpose of this study is to analyze the short-term and long-term responses of SME exports to foreign exchange risk insurance support policies. Based on these empirical studies, we would like to present some operational improvements to the operation of the foreign exchange risk insurance system. Design/methodology - In order to analyze the effect of exchange risk insurance on the exports of SMEs, a VAR model consisting of foreign exchange risk insurance underwriting values, export relative price, and domestic demand pressure, including export volume, was established. The study began with tests of the stationarity of time series data. The unit root tests showed that all concerned variables were non-stationary. Accordingly, the results of the cointegration test showed that the tested variables are not cointegrated. Finally, an impulse response function and variance decomposition analysis were conducted to analyze the impulse of foreign exchange risk insurance on exports of SMEs. Findings - As a result of estimating the VAR (1) model, foreign exchange risk insurance was found to be significant at a 1% significance level for SME' export promotion. In the impulse response analysis, SMEs' export response to the impulse of foreign exchange risk insurance showed that exports gradually increased until the third quarter, and then slowed down. However, the impulse did not disappear, and appeared continuously. Originality/value - This study analyzed the effect of foreign exchange insurance on exports of SMEs by applying the VAR model. In particular, this study is the first to analyze the short-term and long-term effects of foreign exchange risk insurance on exports of SMEs. The empirical evidence in the current study have a policy implication for the policy authority to support and promote the foreign exchange risk insurance in the effect of exchange rate volatility on Korea' export SMEs.

• 서비스연구
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• 제5권1호
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• pp.91-103
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• 2015

본 논문은 한국거래소(KRX)에서 제공한 KT(한국통신)와 SK텔레콤의 현물수익률 및 KT와 SK텔레콤 선물수익률 간의 선도-지연효과를 분석하였다. 분석을 위한 통계분석 기간은 2012년 1월 1일부터 2014년 12월 31일까지이며, 자료는 일별 종가자료 608개를 사용하였고, 분석도구로는 E-Views 6을 이용하여 VAR 모형을 통한 그랜저 인과관계분석(Granger Causality test)과 충격반응분석(Impulse Response Function) 및 분산분해(Variance Decomposition)를 실시하였다. 주요 분석결과는 다음과 같다. 첫째, 그랜저 인과관계분석결과 KT선물수익률과 SK텔레콤 선물수익률은 KT현물수익률과 SK텔레콤 현물수익률에 대하여 강한 예측력이 있다는 것으로 추론할 수 있다. 그러나 KT현물수익률과 SK텔레콤 현물수익률은 KT선물수익률과 SK텔레콤 선물수익률에 대한 예측력이 존재하지 않고 있다는 것을 알 수 있었다. 둘째, 충격반응분석결과 KT선물수익률과 SK텔레콤 선물수익률은 KT현물수익률과 SK텔레콤 현물수익률에 즉각적으로 영향을 미치다 일정시차가 지난 후에 사라지는 것으로 나타났다. 마지막으로 분산분해 분석결과 KT현물수익률과 SK텔레콤 현물수익률의 변화 중에 많은 변화가 KT선물수익률과 SK텔레콤 선물수익률의 변화에 의하여 설명되어짐을 추론할 수 있다. 이러한 분석결과는 개별 주식 현물과 선물을 운용하고 있는 개인투자자 뿐만 아니라 집합투자업자 및 연기금들이 투자정책을 수립하는데 있어서 여러 가지 의미있는 시사점을 제공해 줄 것으로 판단된다. 또한 선물과 옵션시장을 담당하는 한국거래소와 국내외 투자자들이 자산배분정책과 포트폴리오 정책을 수립하는데도 있어서도 유익한 시사점을 제공할 것으로 판단된다.

• 마케팅과학연구
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• 제19권4호
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• pp.24-31
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• 2009

公司生产不同功能, 设计, 颜色的产品. 产品扩散的出现有三个不同的原因. 当存在规模经济, 当这种产品和别的产品一起生产时, 单位成本比单独生产要低. 二, 消费者是异构的, 即它们具有不同的品味, 喜好, 或价格弹性. 一家公司可赚取细分为具有类似特点的不同群体的消费者更多的利润. 例如, 产品扩散通过更准确地满足不同消费者的需要来帮助公司增加利润. 产品扩散的第三个原因是基于战略. 生产一定数量的产品, 不仅可以阻止通过提供给一些少数市场的产品进入, 也使得公司可以有效地应付低价格进入. 通过生产各种产品, 公司可以减少利基, 使潜在进入者有较少进入的诱因. 此外, 企业可以生产新产品来应对进入, 我们称之为战斗品牌. 也就是说, 当一个进入者试图以低廉的价格吸引消费者, 已存在者介绍新的低质量的产品, 同时保持现有产品的价格. 产品扩散的缺点是同型装配. 一些买了高价位的产品的消费者会转向低价位的产品. 此外, 当新产品与对手现有的产品的异化程度不高时, 由于激烈的竞争, 产品扩散会降低利润. 许多研究已经在经济分析和市场营销等领域的产品线竞争的影响. 它们展示了一个垄断者可以通过调整质量来解决市场中的消费者对质量的偏好不同的同型装配的问题. 他们发现, 喜欢高品质的产品的消费者将获得他或她最喜欢的质量, 但没有这方面的偏好的消费者将获得比他或她所喜爱的质量低的产品. 本研究分析了产品的竞争在一个双头垄断市场, 两种不同类型的消费者对质量偏好的影响. 我假设这两家公司将在这个意义上的不对称, 一个运营商可以同时生产高, 低质量的产品, 而一个进入者只能产生低质量的产品. 产品扩散的影响是可以通过比较市场结果来解释, 当已存在的运营商生产两种产品和只生产一种产品时. 在这个案例中, 当已存在的运营商只生产高品质的产品, 由于激烈的竞争, 在喜欢低质量产品的消费群中低质量的产品价格趋于下降. 但由于缺乏竞争, 在喜欢高质量产品的消费群中价格会上涨. 据了解, 当企业在进行价格竞争时, 理想状况是当公司的对 手提高价格时, 此公司也提高价格, 这被称为战略补充. 由于价格是战略性的补充, 我们有两种相反的效果. 事实证明, 一个高品质的产品价格上升, 因为竞争力减弱的积极作用超过了战略互补的负面影响. 这意味着, 已存在的运营商推出了低质量的产品时还需要增加高品质产品的价格. 然而, 在进入者的低质量产品的价格变化是模糊的. 二, 此案例中, 已存在的运营商只生产低品质的产品, 在偏好低质量的消费群中价格往往增加. 但在偏好高质量的消费群中价格往往下降. 低质量产品的价格下降是因为负面影响大于正面影响. 而且, 当已存在的运营商生产两种产品时, 其低质量产品的价格往往较高, 尽管两家的低品质的产品质量一样. 此原因由于对高品质产品价格的负面影响, 运营商没有较大的动机去降低低品质产品的价格. 事实上, 竞争的产品线对利润的影响不仅取决于价格变化, 还取决于销售和同型装配. 如果在边际成本同产品质量的差异相比是适中的话, 产品扩散的积极影响大于负面影响, 从而增加利润. 此外, 如果成本差异是非常大(小), 运营商最好只生产一种低 (高)质量的产品. 而且, 本研究还分析了当公司通过关注战斗品牌来决定产品特征时, 竞争产品线的影响. 最近, 大韩航空和韩亚航空公司建立了廉价航空线路, 分别是Jin线路和釜山线. 来应对Hansung航空和济州航空. 另外, 很多网上书店也进入市场, 例如处于领先地位的实体书店Kyobo已经有了自己的网上书店. 通过战斗品牌, 在它的低品质产品跟新成员比起来有差别时, 一个具有高品质产品的运营商通过生产更多的低质量产品可以增加利润.

• 연구논문집
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• 통권28호
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• pp.73-87
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• 1998

A pneumatic control system of compressed air as a working fluid has a variety of advantages such as low price, high respondence, non-explosion and good control performance and thus has many applications in the field of automobile, electronic and semiconductor industry. However, it has a difficulty in contolling a precise position due to quick response of system and compressibility of working fluid and. in particular, shock stress may occur due to an external load, resulting in fracture of a cylinder cap unless cushion device is equipped in the linear actuator. To avoid this, a cushion device should be installed for damping effect of the external load and the supply pressure as well as for decreasing shock stress and vibration caused by high speed rotation. Previous studies include dimensionless analyses and computer simulations of cushion capability and experiments of horizontally-mounted cylinder performances. A new attempt is experimentally made in this study using a vertically-mounted cylinder under an operation condition of 4, 5 and 6 (bar) as supply pressure and 40, 70 and 100 (kgf) as external load. It turns out that the cushion pressure is mainly a function of the external load rather than the supply pressure. The cushion characteristics was also revealed in the meter-in circuit.

• 동아시아경상학회지
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• 제8권1호
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• pp.57-69
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• 2020

Purpose - This study examines what are the asset market fluctuations in Europe and how each economic variable affects major variables, and explore the dynamics of housing and stock market through Greece. The variables under consideration are balance on current account (BCA), index of stock (STOCK), gross domestic product (GDP), housing price indices (HOUSING), M3, real rate of interest (IR_REAL) and household credits (LOAN). We investigate the functional and causal relationships between housing and stock market. Research design, data, and methodology - Vector error correction model (VECM) is used to figure out the dynamic relationships among variables. This study also contains the augmented Dickey-Fuller unit root, cointegration, Granger causality test, and impulse response function and variance decomposition analysis by EViews 11.0. Results - The statistical tests show that all variables under consideration have one unit root and there is a longterm equilibrium relationship among variables for Greece. GDP, IR_REAL, M3, STOCK and LOAN can be considered as causal factors to affect real estate market, while GDP, LOAN, M3, BCA and HOUSING can bring direct effects to stock market in Greece. Conclusions - It can be judged that the policy that affects the lending policy of financial institutions may be more effective than the indirect variable such as monetary interest rate.

• 복식문화연구
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• 제19권1호
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• pp.163-175
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• 2011

The purposes of this study are to identify quality factors of knitwears, to find out important attributes of knitwears quality, and to find attributes of knitwears quality which improvement are required. College students in the Seoul district participated in the study, a convenience sampling method was used. A questionnaires was arranged with three separates subject sections, importance degree of knitwears quality, satisfaction degree of purchased knitwears, and demographic factors. Data from 280 questionnaires were used for the statistical analysis. For data analysis, factor analysis, paired-samples t-test and multiple response frequency were conducted. The results were as follows. Knitwears quality factors were classified into six subdivisions by factor analysis; physical functions, yarn and fabric properties, fit, symbol, aesthetic, and usefulness. Quality attributes in purchasing knitwears were considered importantly in order of design, textures, color, price, size, and shape stability, etc. Among quality attributes on knitwears, there were significant differences in importance degree and satisfaction degree; important degree was higher than satisfaction degree to six factors on knitwears quality. Especially, in graph according to gap analysis, physical function and symbol were included in IV area, attributes that attention, required of quality improvement. In contrast, yarn and fabric properties, fit, aesthetic, and usefulness were included in I area, strengths, maintained presently quality levels.

• The Journal of Asian Finance, Economics and Business
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• 제8권7호
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• pp.91-101
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• 2021

The paper examines the impact of the COVID-19 pandemic on the stock market prices. The vector autoregression model (VAR) has been used in this analysis to survey 341 stocks on the Ho Chi Minh City Stock Exchange (HOSE) for the period from January 23, 2020 to December 31, 2020. The empirical results obtained from the analysis of 11 economic sectors suggest that there is a statistically significant impact relationship between COVID-19 and the healthcare and utility industries. Additional findings show a statistically significant negative impact of COVID-19 on the utility share price at lag 1. Analysis of impulse response function (IRF) and forecast error variance decomposition (FEVD) show an inverse reaction of utility stock prices to the impact of COVID-19 and a gradual disappearing shock after two steps. Major findings show that there is a clear negative effect of the COVID-19 pandemic on share prices, and the daily increase in the number of confirmed cases, indicate that, in future disease outbreaks, early containment measures and positive responses are necessary conditions for governments and nations to protect stock markets from excessive depreciation. Utility stocks are among the most severely impacted shares on financial exchanges during a pandemic due to the high risk of immediate or irreversible closure of manufacturing lines and poor demand for basic amenities.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제1권3호
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• pp.133-142
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• 2012

쿠르노 모델은 경쟁적 전력시장을 게임이론 기반으로 모델링하기 위한 대표적인 모델이다. 이전 연구에서도 쿠르노 모델을 이용하여 전력시장을 모델링 하기 위한 다양한 시도가 이루어져 왔다. 쿠르노 모델은 몇 개의 주요 발전사업자들이 경쟁하고 그로 인해 시장지배력이 존재하는 과점 시장모델에 적합하다. 쿠르노 모델로 시장을 모델링함에 있어서는 우하향 하는 수요함수의 존재가 선결되어야 한다. 과점에서 시장참여자들은 시장지배력을 활용하여 그들의 이익을 극대화하려고 노력하지만, 우하향하는 시장수요함수에 의해 매출 역시 하락하기 때문에 적당한 지점에서 이러한 시장지배력의 행사를 제한하여야 한다. 스마트그리드에서는 실시간으로 변동하는 요금제와 다양한 전산기반 툴의 활용으로 인해 이러한 수요반응이 더욱 활성화될 것이고, 이 경우 쿠르노 모델은 수요반응 솔루션의 주요 모델로 활용될 것이다. 이에 본 논문은 실제 시장에서 계량경제학적인 접근으로 전력시장의 수요곡선을 추정하는 방법에 대해 제안한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권6호
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• pp.2709-2734
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• 2020

The growing demand to make wireless data services 5G compatible has necessitated the development of an energy-efficient approach for an effective new wireless environment. In this paper, we first propose a cognitive sensor node (CSN) based game theory for deriving energy via a primary user-transmitted radio frequency signal. Cognitive users' time was segmented into three phases based on a time switching protocol: energy harvest, spectrum sensing and data transmission. The proposed model chooses the optimal energy-harvesting phase as the effected factor. We further propose a distributed energy-harvesting model as a utility function via pricing techniques. The model is a non-cooperative game where players can increase their net benefit in a selfish manner. Here, the price is described as a function pertaining to transmit power, which proves that the proposed energy harvest game includes Nash Equilibrium and is also unique. The best response algorithm is used to achieve the green connection between players. As a result, the results obtained from the proposed model and algorithm show the advantages as well as the effectiveness of the proposed study. Moreover, energy consumption was reduced significantly (12%) compared to the benchmark algorithm because the proposed algorithm succeeded in delivering energy in micro which is much better compared to previous studies. Considering the reduction and improvement in power consumption, we could say the proposed model is suitable for the next wireless environment represented in 5G.