• 융합정보논문지
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• 제11권5호
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• pp.94-103
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• 2021

본 연구의 목적은 비트코인 선물의 투자 전략으로 기술적 거래 규칙들을 제안하고, 실증 분석을 통해 투자 성과를 분석하는 것이다. 투자 전략은 표준적인 거래 전략인 VMA, TRB, FR, MACD, RSI, BB 등이며, 2017년 12월 18일부터 2021년 3월 31일까지의 비트코인 선물 일별 자료를 이용하였다. 실증 분석 결과, 추세 추종형 거래 규칙들 모두 비교전략인 Buy & Hold 보다 투자 성과가 높게 나타났다. 코스피200 주가지수 선물과의 비교에서는 비트코인 선물 투자 성과가 높게 나타났다. 특히, 비트코인 선물의 투자 성과는 하방 위험을 반영하는 Sortino Ratio에서 큰 폭으로 증가하였다. 본 연구는 비트코인 선물의 표준적인 기술적 거래 규칙들의 투자 성과를 체계적으로 분석한 첫 시도라는 점에서 학술적 의미를 찾을 수 있다. 향후 연구에서는 비트코인 선물의 가격 예측을 위한 딥러닝 모형이나 기계학습 모형의 활용을 통해 투자 성과를 개선할 필요가 있다.

• 한국자원공학회지
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• 제55권6호
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• pp.624-634
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• 2018

인도네시아는 신규 유전 발견이 줄어들고 원유 순수입국으로 전환됨에 따라 석유 생산을 늘리고자 공동개발계약(Kerja Sama Operasi, KSO)을 통해 소규모 광구 개발을 위한 국내 투자 유치 활성화에 노력하고 있다. 하지만 KSO는 계약자 고위험 저수익의 계약형태이며, 계약자가 석유개발에 대한 모든 비용을 지불하기에 사업 타당성 판단을 위한 경제성 평가가 필수적이다. 이 연구에서는 KSO 계약 조건을 적용하여 인도네시아 소규모 광구 개발에 대한 경제성 평가를 수행하였으며, 민감도 분석을 통해 경제성 평가 시 주요 변수를 파악하였다. 그 결과 유가, CAPEX, OPEX가 경제성 평가에 영향을 미치는 것으로 나타났으며, 소규모 광구에서 상업적인 생산은 다소 어려운 것으로 판단되었다. 향후 이 연구는 국내 기업이 인도네시아 자원개발 투자 시 참고 자료로 활용할 수 있을 것이다.

• 한국군사과학기술학회지
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• 제24권1호
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• pp.50-60
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• 2021

For conventional AESA radars, DC-DC power modules using 300 Vdc have low efficiency, high volume, heavy weight, and high price, which have problems in modularity with T/R module groups. In this paper, to improve these problems, we propose a distributed DC-DC power module with high-voltage 800 Vdc and high-efficiency Step-down Converter. In particular, power requirements for modern and future marine weapons systems and sensors are rapidly evolving into high-energy and high-voltage power systems. The power distribution of the next generation Navy AESA radar antenna is under development with 1000 Vdc. In this paper, the proposed highvoltage, high-efficiency DC-DC power modules increase space(size), weight, power and cooling(SWaP-C) margins, reduce integration costs/risk, and reduce maintenance costs. Reduced system weight and higher reliability are achieved in navy and ground AESA systems. In addition, the proposed architecture will be easier to scale with larger shipboard radars and applicable to other platforms.

• The Journal of Asian Finance, Economics and Business
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• 제8권8호
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• pp.67-74
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• 2021

This study aims to examine and analyze the effect of Risk Profile, Good Corporate Governance (GCG), Earnings, Capital (RGEC), and Earnings per Share (EPS) on stock prices with financial distress as an intervening variable. The sampling technique used purposive sampling based on certain criteria and data used was secondary data, that is, annual reports of commercial banks in Indonesia for the period of 2012-2018 with a sample of 23 banks from a total population of 81 banks. This type of research is explanative with a quantitative descriptive approach to describe or explain quantitative data. The data obtained was analyzed using SEM (Structural Equation Model) with the AMOS Program. The results showed that RGEC, EPS, and financial distress affect stock prices. This is based on testing the direct effect as indicated by a p-value that is smaller than 0.05. Based on the mediation test, the results show that financial distress cannot mediate the effect of RGEC and EPS on stock prices as indicated by a p-value greater than 0.05. The implication of this research is very important for investors to analyze stock price changes based on RGEC, EPS, and financial distress to gain profits. In addition, there are various warning signs indicating that a company is experiencing financial distress or it is heading towards such a state. Being aware of these signs can help prevent failure.

• Journal of Korea Trade
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• 제24권7호
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• pp.38-53
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• 2020

Purpose - A financial crash triggers asset fire sales by foreign investors and, as a consequence, the price of domestic assets severely decreases. Domestic investors take advantage of these low prices by replacing foreign assets with domestic assets, which helps to alleviate the liquidity shock caused by foreigners. However, is the amount of capital retrenchment by domestic investors sufficient to protect the Korean economy from capital stop by foreign investors during financial crisis? This paper answers this question and suggests the implications of this phenomenon for the Korean economy. Design/methodology - We estimate the associations between capital stop and retrenchment and various financial crises such as banking, currency, debt, and inflation crises using the complementary log-log model. Specifically, we use data of gross capital flows to differentiate between the role of foreign and domestic investors in financial markets. Capital stop and retrenchment designate a sharp decrease in gross capital inflows and outflows, respectively. Findings - Capital stop is significantly associated with financial crises, especially currency and debt crises. This implies that increased risk aversion during times of financial turmoil encourages foreign investors to retrench their investments, worsening liquidity shocks. Conversely, capital retrenchment is not significantly associated with such crises. The results show that, although financial crises reduce gross capital outflows, the reduction is not as large as that with capital inflows. Originality/value - The contribution of this paper is threefold. First, this study investigates how domestic investors behave during times of financial distress by studying gross capital flows-not net capital flows. Second, we concentrate on sharp changes in capital flows during crises. Third, we examine the associations between capital stop and retrenchment and financial crises in general, not specific events.

• 한국IT서비스학회지
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• 제21권3호
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• pp.63-72
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• 2022

The extinction crisis of local cities, caused by a population density increase phenomenon in capital regions, directly causes the increase of vacant houses in local cities. According to population and housing census, Gunsan-si has continuously shown increasing trend of vacant houses during 2015 to 2019. In particular, since Gunsan-si is the city which suffers from doughnut effect and industrial decline, problems regrading to vacant house seems to exacerbate. This study aims to provide a foundation of a system which can predict and deal with the building that has high risk of becoming vacant house through implementing a data driven vacant house prediction machine learning model. Methodologically, this study analyzes three types of machine learning model by differing the data components. First model is trained based on building register, individual declared land value, house price and socioeconomic data and second model is trained with the same data as first model but with additional POI(Point of Interest) data. Finally, third model is trained with same data as the second model but with excluding water usage and electricity usage data. As a result, second model shows the best performance based on F1-score. Random Forest, Gradient Boosting Machine, XGBoost and LightGBM which are tree ensemble series, show the best performance as a whole. Additionally, the complexity of the model can be reduced through eliminating independent variables that have correlation coefficient between the variables and vacant house status lower than the 0.1 based on absolute value. Finally, this study suggests XGBoost and LightGBM based machine learning model, which can handle missing values, as final vacant house prediction model.

• 한국지반신소재학회논문집
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• 제22권3호
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• pp.27-35
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• 2023

굴착 공사 중 가시설의 안정성을 확보하는 것은 매우 중요하다. 설계 시 지반의 안정성을 수치해석을 통해 분석하고 있지만, 시공시에는 여건이 달라지기 때문에 계측으로 벽체 안정성을 분석하는 일은 필수불가결한 일이다. 공사현장에서의 계측비용은 매우 낮은 단가로 책정되어있으며 이를 통해 흙막이 벽체의 사고위험성은 예측되고 있다. 따라서 본 연구에서는 흙막이 벽체의 자동 혹은 무선 시스템 계측의 중요성을 가상의 사고사례 분석을 통해 공사기간 및 사고비용을 산정하고 이를 계측비용과 비교하여 무선 및 자동계측 업무의 중요성을 주장하였다. 굴착공사 중 중대형 파괴 시 사고처리 금액에 대하여 계측비용은 5% 미만으로 계측비용을 증가시켜 사고를 미연에 방지하는 것이 경제적일 수 있다.

• 농촌계획
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• 제28권4호
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• pp.93-104
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• 2022

Agriculture is one of the most vulnerable sector to droughts, and drought damage on the agriculture sector could have effects on other sector. Droughts have different characteristics compared to other extreme events, which means more sophisticated methods considering the characteristics of droughts are required when measuring their damage. The purpose of this study is to analyze the damage of droughts based on limited computational general equilibrium model. To be specific, we constructed a CGE model focusing on the agriculture sector in Korea. Also, to limit changes in land use and labor, we limited them, and assume droughts only have effects on productivity of value-added. Lastly, we simulate drought effects on rice production in Korea based on several climate scenarios and GCM to identify the economic effects of droughts. The results show that 1) the cumulated damage of droughts during 2021~2040 is higher than other periods (2040~2061, 2081~2100), 2) the correlation between the damage of droughts and SSP scenarios is insignificant. This result implies the necessity of the effective drought risk management to prevent future droughts effects, irrespective of mitigation policies. 3) Due to increases in rice price, GDP of rice sector is increased. However, GDP of the other sector and consumer welfare are decreased. This result show that indirect effects of droughts would be more important when measuring drought effects on agriculture sector.

• Journal of Korea Trade
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• 제26권3호
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• pp.45-62
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• 2022

Purpose - Using unexpected changes in geopolitical tensions on the Korean peninsula as a quasi-natural experimental setting, we examine whether and how geopolitical risks travel across borders through firm-level imports and exports linkages. We also test whether the effects are driven by either imports or exports and assess whether firms can effectively hedge themselves against geopolitical risks. Design/methodology - We focus on a series of unanticipated geopolitical events taken place in Korea in 2018. Making use of the shocks to geopolitical climate, we identify five milestone events toward peace talks. We employ the event studies methodology. We examine heterogenous firm-level stock price reactions around key event dates depending on firms' exposure to geopolitical risks. As a measure of firms' exposure to geopolitical risks in Korea, we utilize a text-based measure of firm-level trade links. When a firm announces and discusses its purchase of inputs from Korea or sales of outputs to Korea in their annual disclosure filings, we define a firm to have a trade relationship with Korea and have exposure to Korean geopolitical risks. Similarly, we use a measure of a firm's hedging policies based on a firm's textual mention of the use of foreign exchange derivatives in their annual disclosure. Findings - We find that U.S. firms that have direct trade links to Korea gained significantly more value when the intensity of geopolitical risks drops compared to firms without such trade links to Korea. The effects are pronounced for firms purchasing inputs from or selling outputs to Korea. We find that the effectiveness of foreign exchange hedging against geopolitical risks is limited. Originality/value - We document the international transmission of geopolitical uncertainty through trade linkages. Export links as well as import links serve as important nexus of transmission of geopolitical risks across borders. Hedging strategies involving foreign-exchanges derivatives do not seem to insulate firms again geopolitical risks. With the recent movements of localization and reshuffling of the global value chain, our results suggest a significant impact of geopolitical risks in Korea on the construction of the global value chain.

• Journal of Information Science Theory and Practice
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• 제10권spc호
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• pp.56-65
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• 2022

Korea Institute of Science and Technology Information (KISTI) is a Worldwide LHC Computing Grid (WLCG) Tier-1 center mandated to preserve raw data produced from A Large Ion Collider Experiment (ALICE) experiment using the world's largest particle accelerator, the Large Hadron Collider (LHC) at European Organization for Nuclear Research (CERN). Physical medium used widely for long-term data preservation is tape, thanks to its reliability and least price per capacity compared to other media such as optical disk, hard disk, and solid-state disk. However, decreasing numbers of manufacturers for both tape drives and cartridges, and patent disputes among them escalated risk of market. As alternative to tape-based data preservation strategy, we proposed disk-only erasure-coded archival storage system, Custodial Disk Storage (CDS), powered by Exascale Open Storage (EOS), an open-source storage management software developed by CERN. CDS system consists of 18 high density Just-Bunch-Of-Disks (JBOD) enclosures attached to 9 servers through 12 Gbps Serial Attached SCSI (SAS) Host Bus Adapter (HBA) interfaces via multiple paths for redundancy and multiplexing. For data protection, we introduced Reed-Solomon (RS) (16, 4) Erasure Coding (EC) layout, where the number of data and parity blocks are 12 and 4 respectively, which gives the annual data loss probability equivalent to 5×10^-14. In this paper, we discuss CDS system design based on JBOD products, performance limitations, and data protection strategy accommodating EOS EC implementation. We present CDS operations for ALICE experiment and long-term power consumption measurement.