• Journal of Korean Society of Industrial and Systems Engineering
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• v.30 no.1
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• pp.66-73
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• 2007

일반 투자안의 의사결정에서와 마찬가지로 산업설비의 경제성 분석에서도 가장 중요한 결정 요소 중의 하나가 설비의 생존곡선 추정이다. 설비의 자산 가치가 감소하는 원인은 여러 가지가 있으나, 여러 원인 중 물리적 훼손이 과거의 산업설비에서는 가장 중요한 원인이었으므로 기존의 생존모형 분석에서는 lows 생존곡선을 이용하여 설비의 생존곡선을 추정하였다. 그러나 새로운 기술상의 변화로 인한 첨단 생산시스템의 설비교체 분석 시에는 적합지 않다. 따라서, 본 연구에서 제안된 혼합형 Weibull 함수를 이용하여 설비의 폐기 형태를 추정함으로써 설비들의 실제적인 생존곡선을 정확하게 파악할 수 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2020.05a
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• pp.188-190
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• 2020

최근 4차 산업혁명과 더불어 센서 네트워크와 같은 최신 무선통신 기술들의 기반시설 적용을 위한 연구들이 활발하게 이루어지고 있다. 원자력시설 또한, 보안 및 비상대응 시스템에 무선통신을 적용하기 위한 연구들이 진행되고 있으며, 미국과 UAE의 경우 이미 원자력시설에 무선통신을 적용하여 사용하고 있다. 그러나 무선통신의 경우, 물리적인 네트워크 접근 경로가 존재하지 않기 때문에 통신 경로에 대한 접근통제가 불가능하며 광범위한 지역에 네트워크를 설치하는 경우 중계 단말 수량의 증가로 인한 접근통제 취약점이 발생할 가능성이 있다. 이와 같은 무선통신의 특성 때문에 원자력시설의 필수디지털자산에 무선 네트워크를 적용 시 현재의 통신 경로 접근통제 등의 유선 통신을 기준으로 작성된 접근통제 규제기준으로는 무선통신에 대한 접근통제를 이행하기에는 부족함이 있다. 이에 본 논문에서는 무선 네트워크 접근통제를 위한 규제 기준 개선안을 제시한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.746-748
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• 2022

투자 분배 시스템은 지속성, 수익성, 변동성, 하방경직성 등 각각의 지표를 찾아내는 데이터 분석을 조합한 시스템으로 MLP 신경망을 통한 시황을 예측으로 투자 경험이 부족한 일반 사용자에게 안정적인 투자 분배 전략을 제공한다. 투자분배 시스템 구현을 위하여 추가적으로 금융시장에 대한 회귀분석, 켈리 공식과 같은 도구를 활용하였다.

• The Korean Journal of Financial Management
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• v.22 no.2
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• pp.43-69
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• 2005

This study provides empirical evidence that the stochastic beta model based on Bayesian analysis outperforms the existing conditional beta model and GARCH model in terms of the estimation accuracy and the explanatory power in the cross-section of stock returns in Korea. Betas estimated by the stochastic beta model explain $30{\sim}50%$ of the cross-sectional variation in stock-returns, whereas other time-varying beta models account for less than 3%. Such a difference in explanatory power across models turns out to come from the fact that the stochastic beta model absorbs the variation due to the market anomalies such as size, BE/ME, and idiosyncratic volatility. These results support the rational asset pricing model in that market anomalies are closely related to the variation of expected returns generated by time-varying betas.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.6
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• pp.715-721
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• 2012

A threat evaluation is the technique which decides order of priority about tracks engaging with enemy by recognizing battlefield situation and making it efficient decision making. That is, in battle situation of multiple target it makes expeditious decision making and then aims at minimizing asset's damage and maximizing attack to targets. Threat value computation used in threat evaluation is calculated by sensor data which generated in battle space. Because Battle situation is unpredictable and there are various possibilities generating potential events, the damage or loss of data can make confuse decision making. Therefore, in this paper we suggest that substantial threat value calculation using learning bayesian network which makes it adapt to the varying battle situation to gain reliable results under given incomplete data and then verify this system's performance.

• The Journal of Small Business Innovation
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• v.19 no.3
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• pp.43-55
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• 2016

This study examines the implications of special items (SI) for future earnings using quarterly Korean data over the period from 2011 to 2014. Due to the lack of identification of SI in Korea, I choose several items as special items if they are material and non-recurring items following prior studies. Then I regressed seasonally-differenced future earnings on positive and negative SI and found that their effects on future earnings were different. While negative SI are explained by inter-period expense transfer, positive SI are not well-described by traditional prototypes. Next, I regressed seasonally-differenced future earnings on negative SI sub-types as they are heterogeneous in nature and have differing implications for future earnings. While PPE impairments and intangibles impairments are partly explained by the inter-period expense transfer, unspecified loss of other loss items are not. Interestingly, these effects are attenuated or disappear in the Kosdaq market when the markets are divided into the Kospi and Kosdaq markets.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.11
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• pp.1050-1067
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• 2014

CAS(Close Air Support) is aircraft attack against hostile targets that are in close proximity to friendly forces. Immediate CAS is the mission that attack unplanned targets, and especially the distribution of suitable aircraft assets makes huge effect on the result of immediate CAS mission. But It is hard to find a previous studies on immediate CAS sortie distribution with aircraft suitability. This study suggests a methodology with aircraft suitability for immediate CAS sortie distribution. The methodology consists of 3 steps. Firstly, we analyze target information for situational awareness. Secondly, we calculate each aircraft's suitability value per each target based on the result of previous analysis. Lastly, we suggest immediate CAS sortie distribution based on the aircraft adoptability value to a decision maker. This methodology will provide not only quantitative analysis, but also decision making of immediate CAS sortie distribution more timely and effectively.

• International Area Studies Review
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• v.12 no.2
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• pp.149-173
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• 2008

This paper empirically studies the relationship between R&D expenditures and firms value. First, we can conjecture that R&D expenditures are enhancing the firms value. Such findings depend on an existing research, which R&D expenditures are intangible asset rather than expenses. Although, under U.S. accounting standards, financial statements do not report intangible assets but costs. Second, we can conjecture that short-term, the rate of increase in R&D expenditures had negative influence on firms valuation, because such findings indicates that R&D spending of costs incur mis-pricing. But long-term, consistently R&D expenditures may attract investors on the stock market. Third, lately firms focus on capital efficiency management, such a firms R&D expenditures incur high ROE. Generally investors put too much confidence in capital efficiency management and high ROE may attract investors on the stock market. Finally, High-Tech through the R&D investment improve firms competitive advantage, by competitive advantage, firms have reduced cost and raised productivity in the end improve firms value.

• 한국노년학
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• v.30 no.4
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• pp.1045-1058
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• 2010

Based on Rawl's Justice Theory, the author examines the rationales for educating older adults and advocates for their needs for just distributions of educational resources and opportunities. The author also seeks policy implications for establishing just educational systems for older citizens. On the basis of Rawl's Justice Theory, the essential principles for realizing social justice are presented. The author points out the Veil of Ignorance and Rational Indifference. As the practical methods for achieving social justice, the author presents Exclusion of Coincidence, Difference Principle, Democratic Equality, and Common Asset. Implications for establishing just education systems for older adults include: 1) The least advantaged groups such as older adults, females, and the disabled should not be discriminated in the distribution of educational resources; 2) People with higher capacities are obliged to serve less capable people; and 3) Older adults should mobilize all resources to empower themselves and to develop their potentials. The author concludes that Rawl's Justice Theory can be tapped into as a useful ideological framework in order to expand educational resources and opportunities for older adults.

• Journal of Internet of Things and Convergence
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• v.10 no.1
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• pp.7-12
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• 2024

To trade cryptocurrency, traders require a personal cryptocurrency wallet. Cryptocurrency itself using blockchain technology is guaranteed excellent security and reliability, so the threat of blockchain hacking is almost impossible, but the exchange environment used by traders for transactions is most subject to hacking threats. Even if transactions are made safely through blockchain during the transaction process, if the trader's wallet information itself is hacked, security cannot be secured in these processes. Exchange hacking is mainly done by stealing a trader's wallet information, giving the hacker access to the victim's wallet assets. In this paper, to prevent this, we would like to reconstruct the existing Hyperledger Fabric structure and propose a system that verifies the identity integrity of traders during the transaction process using whitelisting. The advantage is that through this process, damage to cryptocurrency assets caused by hackers can be prevented and recognized. In addition, we aim to point out and correct problems in the transaction process that may occur if the victim's wallet information is stolen from the existing Hyperledger Fabric.