• 한국산학기술학회논문지
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• 제17권5호
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• pp.49-55
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• 2016

각종 전기전자 시스템에서 발생하는 EMI 성분을 공통성분 (CM) 과 차동성분 (DM) 으로 분리하기 위해서 수동분리기와 능동분리기를 연구하였다. CM과 DM 성분 분리기는 능동 EMI 필터를 효과적으로 구현하는데 중요한 요소이다. 수동분리기는 인덕터값을 실현하는데 있어 기술적으로 쉽고 가격이 저렴한 장점이 있으나 상대적으로 큰 오차값이 발생하여 정밀 제작이 요청되므로 부피가 커지고 core의 선택이 어려워지는 단점이 있다. 능동분리기는 OP-Amp를 이용하기 때문에 부피가 작아지고 CM, DM 분리의 정확도를 높일 수 있는 장점이 있으나 주파수 특성이 광대역이어야 하고 가격이 비싸며 별도 DC 전원이 요청되는 단점이 있다. 본 연구에서는 기존의 수동 분리기와 새롭게 제안한 능동 분리기를 적용한 각각의 EMI 필터의 특성을 분석하였다. 따라서 높은 정밀도가 필요한 고가의 장비에는 능동 분리기를 사용하는 것이 정밀도를 개선하는데 유리하며, 일반적인 용도로 저렴한 가격이 요청되며 충분한 설계 면적을 활용할 수 있고 높지 않은 정확도에서도 동작 가능하다면 수동 분리기가 더 바람직하다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2000년도 제18회 학술발표회 논문개요집
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• pp.80-80
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• 2000

Surface acoustic wave (SAW) devices have become more important as mobile telecommunication systems need h호-frrequency, low-loss, and down-sized components. Higher-frequency SAW divices can be more sasily realized by developing new h호-SAW-velocity materials. The ZnO/diamond/Si multilasyer structure is one of the most promising material components for GHz-band SAW filters because of its SAW velocity above 10,000 m/sec. Silicon carbide is also a potential candidate material for high frequency, high power and radiation resistive electronic devices due to its superior mechanical, thermal and electronic properties. However, high price of commercialized 6- or 4H-SiC single crystalline wafer is an obstacle to apply SiC to high frequency SAW devices. In this study, single crystalline 3C-SiC thin films were grown on Si (100) by MOCVD using bis-trimethylsilymethane (BTMSM, C7H20Si7) organosilicon precursor. The 3C-SiC film properties were investigated using SEM, TEM, and high resolution XRD. The FWHM of 3C-SiC (200) peak was obtained 0.37 degree. To investigate the SAW propagation characteristics of the 3C-SiC films, SAW filters were fabricated using interdigital transducer electrodes on the top of ZnO/3C-SiC/Si(100), which were used to excite surface acoustic waves. SAW velocities were calculated from the frequency-response measurements of SAW filters. A generalized SAW mode. The hard 3C-SiC thin films stiffened Si substrate so that the velocities of fundamental and the 1st mode increased up to 5,100 m/s and 9,140 m/s, respectively.

• Journal of Korea Trade
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• 제25권1호
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• pp.1-17
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• 2021

Purpose - The global trend of protectionism has expanded since the onset of US President Donald Trump's administration in 2017. This global phenomenon has led to a significant reduction in world trade volume and a negative impact on economic development in some countries where the external sector accounts for a large proportion of GDP. Although Korea is a country vulnerable to this deteriorating trade environment, few studies have examined the relationship between protectionism and its business cycles based on Korean data. Thus, this paper investigates the impact of protectionism on Korea's business cycle. Design/methodology - To identify future implications, we conduct a structural vector autoregression (VAR) analysis using monthly Korean data from 1994 to 2015. Macroeconomic variables in the model include the industrial production index, inflation rates, exports (or net exports), interest rates, and exchange rates. For the identification of the shock reflecting the expansion of protectionism, we use an antidumping investigation (ADI) data. Since ADIs are followed generally by the imposition of antidumping tariffs, they have no contemporaneous impact on tariffs and are also contemporaneously exogenous to other endogenous variables in the VAR model. We examine two kinds of ADI shocks i) shocks on Korean exports imposed by Korea's trading partners (ADI-imposed shocks) and ii) shocks on imports imposed by the Korean government (ADI-imposing shocks). Findings - We find that Korea's exports decline sharply due to ADI-imposed shocks; the lowest point at the third month after the initial shock; and do not recover until 24 months later. Simultaneously, the inflation rate decreases. Therefore, the ADI-imposed shock can be regarded as a negative shock on the demand curve where both production and price decrease. In contrast, the ADI-imposing shock generates a different response. The net exports decline, but the inflation rate increases. These can be seen as standard responses with respect to the negative shock on the supply curve. Originality/value - We shed light on the relationship between protectionism and Korea's economic fluctuations, which is rarely addressed in previous studies. We also consider the effects of both protective policy measures on imports to Korea imposed by the Korean government and on policy measures imposed by Korea's trading partner countries on its exports.

• 한국인터넷방송통신학회논문지
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• 제19권3호
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• pp.17-23
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• 2019

IaaS는 인프라 하드웨어를 소유하지 않고 필요에 따라 임대하는 새로운 방식의 컴퓨팅 서비스로서 비용측면에서 매우 효율적인 것으로 알려져 있다. 일반적으로 사용량에 따른 과금 방식을 채택하므로 인프라 비용에 민감한 서비스를 운영하기에 적합하다. 이러한 서비스를 운영하는 책임자는 예상되는 소요 비용을 조기에 파악하여 클라우드 활용 정책을 적시에 변경하기를 원할 것이다. 그러나 클라우드 서비스 제공자들은 십수시간 지연된 과금 정보를 제공하여 신속한 대처가 불가능하다. 본 논문에서는 가상 머신 인스턴스 수준에서 사용량을 모니터링하고 이에 기반하여 실시간 IaaS 비용 예측 모델을 제안한다. 이 모델 검증을 위하여 1학기 동안의 공용 클라우드 기반의 PC 실습실 서비스를 운용하였으며, 이를 통하여 부과된 실제 금액과의 차이는 평균 5.2% 이하임을 확인하였다.

• 아태비즈니스연구
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• 제11권4호
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• pp.189-203
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• 2020

Purpose - This study aims in analyzing the dynamic relationship between household loans and housing prices according to the characteristics of depository institutions after the financial crisis, identifying the recent trends between them, and making policy suggestions for stabilizing house prices. Design/methodology/approach - The monthly data used in this study are household loans, household loan interest rates, and housing prices ranging from January 2012 to May 2020, and came from ECOS of the Bank of Korea and Liiv-on of Kookmin Bank. This study used vector auto-regression, generalized impulse response function, and forecast error variance decomposition with the data so as to yield analysis results. Findings - The analysis of this study no more shows that the household loan interest rates in both deposit banks and non-bank deposit institutions had statistically significant effects on housing prices. Also, unlike the previous studies, there was statistically significant bi-directional causality between housing prices and household loans in neither deposit banks nor non-bank deposit institutions. Rather, it was found that there is a unidirectional causality from housing prices to household loans in deposit banks, which is considered that housing prices have one-sided effects on household loans due to the overheated housing market after the financial crisis. Research implications or Originality - As a result, Korea's housing market is closely related to deposit banks, and housing prices are acting as more dominant information variables than interest rates or loans under the long-term low interest rate trend. Therefore, in order to stabilize housing prices, the housing supply must be continuously made so that everyone can enjoy housing services equally. In addition, the expansion and reinforcement of the social security net should be realized systematically so as to stop households from being troubled with the housing price decline.

• 산업경영시스템학회지
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• 제43권4호
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• pp.15-22
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• 2020

Economic indicators are a factor that affects air cargo volume. This study analyzes the different factors affecting air cargo volume by each Chinese cities according to the main characteristics. The purpose of this study is to help companies related to China, airlines, and other stakeholders predict and prepare for the fluctuations in air cargo volume and make optimal decisions. To this end, 20 economic data were used, and the entire data was reduced to 5 dimensions through factor analysis to build a dataset necessary and evaluated the influencing factors by multi regression. The result shows that Macro-Economic Indicators, Production/Service indicators are significant for every cities and Chinese manufacture/Customer indicators, Korean manufacture/Oil Price indicators, Trade/Current indicators are significant for each other city. All adjusted R2 values are high enough to explain our model and the result showed excellent performance in terms of analyzing the different factors which affects air cargo volume. If companies that are currently doing business with China can identify factors affecting China's cargo volume, they can be flexible in response to changes in plans such as plans to enter China, production plans and inventory management, and marketing strategies, which can be of great help in terms of corporate operations.

• 유통과학연구
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• 제20권8호
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• pp.93-103
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• 2022

Purpose: Online shopping festivals have quickly become the newest trend in online shopping worldwide due to the COVID-19 pandemic. This has led to marketing distribution channels that traditionally emphasized traditional techniques having turned to electronic commerce platforms. Although the pandemic scenario encourages online purchasing, other factors, such as the influence of participation intention to shop during the Online Shopping Festival, must also be considered. Research design, data and methodology: Multiple linear regression analysis was used to test the hypothesis based on data from 121 respondents who are actively involved with online shopping activities in Klang Valley, Selangor. Results: The results of this study show that promotion categories and the perceived influence of mass participation have a significant influence on participation intention. Meanwhile, the perceived temptation of price promotion and perceived fun promotional activities did not significantly influence participation intention. Conclusions: Theoretically, this study contributes to the literature by using the Theory of Planned Behavior and Stimulus-Response models to explain the factors that drive participation intention for online shopping. In practice, this study attracts and encourages customers to shop during the festival day because various attractive promotions are offered by sellers in Malaysia.

• 한국IT서비스학회지
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• 제21권2호
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• pp.1-26
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• 2022

This study classified five types of online food subscription economy: replenishment, curation, surprise, membership, and visitation. An online survey was conducted with 314 customers who experienced 5 types of online subscription economy. This study selected the characteristics of the food subscription economy as convenience, perceived personalization, economic utility, and timeliness through previous studies. The effect of the four characteristics on perceived value (utilitarian and emotional) and the relationship between customer engagement and perceived value, which are dependent variables that have never been used in the food subscription economy, were verified through the S-O-R model. In this relationship, we demonstrated how consumers' personal tendencies, such as need for cognitive closure and self-efficacy, mediate between timeliness and perceived value related to online food delivery. The study results are as follows. Perceived personalization, convenience, and timeliness had a positive effect on the utilitarian value in the order. It also had a positive effect on emotional values in the order of perceived personalization and timeliness. On the other hand, economic utility had no significant effect on practical branches. Customer engagement had a positive effect in the order of emotional value and utilitarian value. The lower the need for cognitive closure the more positive the utilitarian value. The lower the self-efficacy, the more positive the emotional value was perceived. Through the above study, companies that want to operate or start an online food subscription economy need a strategic approach rather than unreasonable price discounts in pricing policy. In addition, it is necessary to focus on marketing activities that provide emotional value by focusing on perceived personalization, which is the satisfaction factor of online food subscription.

• 수산경영론집
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• 제52권2호
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• pp.1-31
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• 2021

This study is to evaluate the prior economic feasibility of the off-shore fisheries stock enhancement project. The main findings of this study can be summarized as follows: first, offshore fisheries stock enhancement project shall be implemented by dividing them into 1st·2nd·3rd projects for efficient promotion. The 1st·2nd·3rd projects will be conducted in a total of 50 locations (the eastern sea, the western sea, the southern sea, and the jeju sea areas), and the project period per unit will be five years, which will cost 1 trillion won. Second, according to the results of the survey on public awareness, the most consumed marine species in Korea over the past year were analyzed in the order of mackerel, hairtail, squid, yellow corvina, blue crab, and cod. The dominant response to the reason for consuming marine products in Korea was healthy well-being food and safe food. In addition, 67.9% of them have hesitated to purchase offshore fish species over the past year due to high prices, indicating that they are burdened by high prices. On the other hand, 79% of the respondents said that the government's policy was insufficient, according to a survey on whether the government's coastal marine resource creation policy was sufficient. Third, as a result of preliminary economic analysis of offshore fisheries stock enhancement project, the benefit-cost ratio is 4.01, net present price is 1,283.7 billion won, and internal rate of return is 91.7% per year, which means that the economic analysis ensures the feasibility of the projects. The results of this study provide useful information on securing or organizing budgets for offshore fisheries stock enhancement project by securing economic feasibility as a national infrastructure project that increases fishery income and public benefits such as consumption of marine products.

• 한국컴퓨터정보학회논문지
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• 제27권9호
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• pp.243-251
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• 2022

부동산 산업은 경제와 높은 상관관계를 갖는 기초산업이다. 과거 20년 동안 중국경제성장을 가속화하면서 부동산 산업도 큰 변화를 보이고 있다. 이에 본 연구는 기존 경제성장지표인 GDP, 소득, 부동산 가격 및 금리 등 거시경제요인이 주택시장 가격상승을 종합적으로 설명하지 못한 점을 감안하여 행동경제학에서 심리지수가 주택시장에 미치는 영향을 분석한다. 방법론적으로 주성분분석법(PCA)을 활용하여 중국심천지역을 중심으로 부동산시장 수요자 심리지수 및 공급자 심리지수를 각각 도출하고 벡터자기회귀(VAR)모형을 통해 심리지수가 주택수익률에 대한 영향을 실증분석으로 진행한다. 그 결과 공급자의 심리는 주택시장에 긍정적인 영향을 미친 반면, 수요자의 심리는 부정적인 영향을 미치고 있다. 또한 공급자의 심리가 높은 경우에는 수요자의 심리가 높은 경우와 다른 영향을 미치고 있은 것을 밝혔다.