• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.3
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• pp.501-509
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• 2011

In this paper, we offer a new strategic Portfolio Model for national IT R&D project selection in Korea. A risk and return (R-R) Portfolio Model was developed using an objectively quantified index on the two axes of risk and return, in order to select a strategic project and allocate resources in compliance with a national IT R&D strategy. We strategize using the R-R Portfolio Model to solve the non-strategy and subjectivity problems of the existing national R&D project selection Model. We also use the quantified evaluation index of the IT technology road map (TRM) and the technology level Survey (TLS) for the subjectivity of project selection, and try to discover the weights using the analytic hierarchy process (AHP). In addition, we intend to maximize the chance for a successful national IT R&D project, by selecting a strategic Portfolio project and balancing the allocation of resources effectively and objectively.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.659-662
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• 2004

An analysis of the AF is performed for each bridge pier exposed to ship collision. From this analysis, the impact lateral resistance can be determined for each pier. The bridge pier impact resistance is selected using a probability-based analysis procedure in which the predicted AF, from the ship collision risk assessment is compared to an acceptance criterion. In this study, the acceptance criterion is allocated to each pier using allocation weights based on the previous predictions. To determine the design impact lateral resistance of bridge components such pylon and pier, the numerical analysis is performed iteratively with the analysis variable of impact resistance ratio of pylon to pier. The design impact lateral resistance can vary greatly among the components of the same bridge, depending upon the waterway geometry, available water depth, bridge geometry, and vessel traffic characteristics.

• Proceedings of the Korea Information Processing Society Conference
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• 2020.05a
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• pp.439-441
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• 2020

기존의 균등배분, 마코위츠, Recurrent Reinforcement Learning 방법들은 수익들을 최대화하거나 위험을 최소화하고, Risk Budgeting 방법은 각 자산에 목표 리스크를 배분하여 최적의 포트폴리오를 찾는다. 그러나 이 방법들은 미래의 최적화된 포트폴리오를 잘 찾아주지 못하는 문제점들이 있다. 본 논문은 자산 배분을 위한 Deterministic Policy Gradient 기반의 Actor Critic 모델을 개발하였고, 기존의 방법들보다 성능이 우수함을 검증한다.

• Journal of the Korean Society for Railway
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• v.19 no.2
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• pp.170-186
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• 2016

This paper introduces a multi-phase fuzzy risk graph model, representing a method for determining for SIL values for railway industry systems. The purpose of this paper is to compensate for the shortcomings of qualitative determination, which are associated with input value ambiguity and the subjectivity problem of expert judgement. The multi-phase fuzzy risk graph model has two phases. The first involves the determination of the conventional risk graph input values of the consequence, exposure, avoidance and demand rates using fuzzy theory. For the first step of fuzzification this paper proposes detailed input parameters. The fuzzy inference and the defuzzification results from the first step will be utilized as input parameters for the second step of the fuzzy model. The second step is to determine the safety integrity level and tolerable hazard rate corresponding to be identified hazard in the railway industry. To validate the results of the proposed the multi-phase fuzzy risk graph, it is compared with the results of a safety analysis of a level crossing system in the CENELEC SC 9XA WG A0 report. This model will be adapted for determining safety requirements at the early concept design stages in the railway business.

• Journal of Science and Technology Studies
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• v.15 no.2
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• pp.229-262
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• 2015

Toxic tort cases have increased dramatically since the 1970s, as large technological systems, such as nuclear power plants and chemical factories, or mass-produced, high-tech products, had exposed citizens and consumers to dangerous substances. It was, however, difficult to establish causal connection between exposure and the alleged harms in many of the environmental, pollution, and product liability cases under the framework of tort law conception of causation and responsibility. Science and law was called upon to resolve such 'late modern' legal cases where true causes are hard to find, where no single explanatory factor is sufficient for explaining diseases like cancer. This article examines how plaintiffs in the Korean tobacco litigation mobilized such late modern tools in science and law, such as epidemiology and the allocation of the burden of proof, in the context of the global circulation of science and law. It further shows how a set of the scientific theories and legal arguments developed in order to cope with late modern risk played a central role in establishing a causation between smoking and cancer in 2011. This article suggests that STS scholars can fruitfully examine the interaction between science and law as a way to understand and engage with social and legal issues engendered by late modern risk.

• Journal of the Society of Disaster Information
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• v.20 no.2
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• pp.339-350
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• 2024

Purpose: This study analyzes accessibility of 10 hydrogen charging stations in Seoul and identifies areas that were difficult to access. The purpose is to re-analyze accessibility by adding a new location in terms of equity and safety of location placement, and then draw implications by comparing the improvement effects. Method: By applying the location-allocation model and the service area model based on network analysis of the ArcGIS program, areas with weak access were identified. The location selection method applied the 'Minimize Facilities' method in consideration of the need for rapid arrival to insufficient hydrogen charging stations. The limit distance for arrival within a specific time was analyzed by applying the average vehicle traffic speed(23.1km/h, Seoul Open Data Square) in 2022 to three categories: 3,850m(10minutes), 5,775m(15minutes), 7,700m(20minutes). In order to minimize conflicts over the installation of hydrogen charging stations, special standards of the Ministry of Trade, Industry and Energy applied to derive candidate sites for additional installation of hydrogen charging stations among existing gas stations and LPG/CNG charging stations. Result: As a result of the analysis, it was confirmed that accessibility was significantly improved by installing 5 new hydrogen charging stations at relatively safe gas stations and LPG/CNG charging stations in areas where access to the existing 10 hydrogen charging stations is weak within 20 minutes. Nevertheless, it was found that there are still areas where access remains difficult. Conclusion: The location allocation model is used to identify areas where access to hydrogen charging stations is difficult and prioritize installation, decision-making to select locations for hydrogen charging stations based on scientific evidence can be supported.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1A
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• pp.1-9
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• 2006

An analysis of the annual frequency of collapse(AF) is performed for each bridge pier exposed to ship collision. From this analysis, the impact lateral resistance can be determined for each pier. The bridge pier impact resistance is selected using a probability-based analysis procedure in which the predicted annual frequency of bridge collapse, AF, from the ship collision risk assessment is compared to an acceptance criterion. The analysis procedure is an iterative process in which a trial impact resistance is selected for a bridge component and a computed AF is compared to the acceptance criterion, and revisions to the analysis variables are made as necessary to achieve compliance. The distribution of the AF acceptance criterion among the exposed piers is generally based on the designer's judgment. In this study, the acceptance criterion is allocated to each pier using allocation weights based on the previous predictions. To determine the design impact lateral resistance of bridge components such pylon and pier, the numerical analysis is performed iteratively with the analysis variable of impact resistance ratio of pylon to pier. The design impact lateral resistance can vary greatly among the components of the same bridge, depending upon the waterway geometry, available water depth, bridge geometry, and vessel traffic characteristics. More researches on the allocation model of AF and the determination of impact resistance are required.

• The Journal of the Korea Contents Association
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• v.22 no.10
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• pp.691-702
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• 2022

This study verifies the diversification effect when non-financial asset such as fractional music royalties investment which is recently get interest from masses, is included in traditional global asset allocation portfolio. From Jan 2019 when Music Royalties index is announced to Jun 2022, compared traditional global asset allocation portfolio and the portfolio included with music royalties. To eliminate the enhancement effect from portfolio strategy itself rather than including non-financial asset, used the four basic portfolio strategy such as buy & hold, constant rebalanced, mean variance, risk parity. As a result, all the portfolios included with music royalties shows less risk with higher returns. This means the sharpe ratio has enhanced and that results the portfolio diversification effect is placed. The empirical analysis of the study found academic significance in that the portfolio included with music royalties investment has diversification effect, and show the possibilities the not only on the music royalties, other non-financial asset can be shown the portfolio diversification effect.

• Korean Journal of Acupuncture
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• v.37 no.3
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• pp.131-144
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• 2020

Objectives : The aim of this study is to analyze the details of acupuncture treatment methods and the reporting quality of acupuncture on Carpal Tunnel Syndrome (CTS). Methods : Search was conducted in Pubmed, EMBASE, and Cochrane Library for acupuncture studies on CTS. The reporting quality of acupuncture treatment was assessed using the following guidelines: Standards for Reporting Interventions in Clinical Trials of Acupuncture (STRICTA) for analyzing the method of acupuncture treatment, Consolidated Standards of Reporting Trials (CONSORT) for analyzing study design and study process, and Risk of Bias (ROB) for analyzing bias. The number of reported items was calculated and evaluated as a proportion. The reported proportion of each study was classified into three grades: Grade A (% score ≥75), Grade B (50≤ % score <75), and Grade C (% score <50). Results : A total of 9 Randomized Controlled Trials (RCTs) were included in this study. All trials reported 12 items (66.67%) on average in STRICTA guidelines. Five studies were conducted with manual acupuncture and 3 studies were conducted with electroacupuncture. PC7 (Daereung) was most frequently used to treat CTS. In STRICTA guideline evaluation, 3 studies were classified as Grade A, 5 studies were classified as Grade B, and 1 study was classified as Grade C. In the CONSORT statement assessment, all trials reported an average of 20.56 items. Of the 9 RCTs, 6 studies were classified as Grade B and 3 studies were classified as Grade C. In ROB assessment, most studies showed a low (63.49%) or unclear (26.98%) risk of bias. The selective reporting bias and the incomplete outcome data bias were found to have the lowest risk of bias, and the allocation concealment of selection bias was found to have the most unclear risk of bias. Conclusions : Recent acupuncture studies on CTS showed moderate reporting quality. However, more detailed reports on acupuncture are still needed to establish more solid evidence of acupuncture treatment.

• Journal of the Korean Society for Railway
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• v.19 no.2
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• pp.145-158
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• 2016

This paper introduces a risk graph which is one method for determining the SIL as a measure of the effectiveness of signaling system. The purpose of this research is to make up for the weakness of the qualitative determination, which has input value ambiguity and a boundary problem in the SIL range. The fuzzy input valuable consists of consequence, exposure, avoidance and demand rate. The fuzzy inference produces forty eight fuzzy rule by adapting the calibrated risk graph in the IEC 61511. The Max-min composition is utilized for the fuzzy inference. The result of the fuzzy inference is the fuzzy value. Therefore, using the de-fuzzification method, the result should be converted to a crisp value that can be utilized for real projects. Ultimately, the safety requirement for hazard is identified by proposing a SIL result with a tolerable hazard rate. For the validation the results of the proposed method, the fuzzy risk graph model is compared with the safety analysis of the signaling system in CENELEC SC 9XA WG A10 report.