• The Korean Journal of Applied Statistics
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• v.34 no.3
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• pp.309-327
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• 2021

Dynamic treatment regimes (DTRs) are decision-making rules designed to provide personalized treatment to individuals in multi-stage randomized trials. Unlike classical methods, in which all individuals are prescribed the same type of treatment, DTRs prescribe patient-tailored treatments which take into account individual characteristics that may change over time. The Q-learning method, one of regression-based algorithms to figure out optimal treatment rules, becomes more popular as it can be easily implemented. However, the performance of the Q-learning algorithm heavily relies on the correct specification of the Q-function for response, especially in observational studies. In this article, we examine a number of double-robust weighted least-squares estimating methods for Q-learning in high-dimensional settings, where treatment models for propensity score and penalization for sparse estimation are also investigated. We further consider flexible ensemble machine learning methods for the treatment model to achieve double-robustness, so that optimal decision rule can be correctly estimated as long as at least one of the outcome model or treatment model is correct. Extensive simulation studies show that the proposed methods work well with practical sample sizes. The practical utility of the proposed methods is proven with real data example.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.6
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• pp.1087-1101
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• 2020

Various security devices are used to protect internal networks and valuable information from rapidly evolving cyber attacks. Firewall, which is the most commonly used security device, tries to prevent malicious attacks based on a text-based filtering rule (i.e., access control policy), by allowing or blocking access to communicate between inside and outside environments. However, in order to protect a valuable internal network from large networks, it has no choice but to increase the number of access control policy. Moreover, the text-based policy requires time-consuming and labor cost to analyze various types of vulnerabilities in firewall. To solve these problems, this paper proposes a 3D-based hierarchical visualization method, for intuitive analysis and management of access control policy. In particular, by providing a drill-down user interface through hierarchical architecture, Can support the access policy analysis for not only comprehensive understanding of large-scale networks, but also sophisticated investigation of anomalies. Finally, we implement the proposed system architecture's to verify the practicality and validity of the hierarchical visualization methodology, and then attempt to identify the applicability of firewall data analysis in the real-world network environment.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.26 no.4
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• pp.307-326
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• 2021

Real-time sea level observations from tide gauges include missing and erroneous values. Classification as abnormal values can be done for the latter by the quality control procedure. Although the 3𝜎 (three standard deviations) rule has been applied in general to eliminate them, it is difficult to apply it to the sea-level data where extreme values can exist due to weather events, etc., or where erroneous values can exist even within the 3𝜎 range. An artificial intelligence model set designed in this study consists of non-annotated recurrent neural networks and ensemble techniques that do not require pre-labeling of the abnormal values. The developed model can identify an erroneous value less than 20 minutes of tide gauge recording an abnormal sea level. The validated model well separates normal and abnormal values during normal times and weather events. It was also confirmed that abnormal values can be detected even in the period of years when the sea level data have not been used for training. The artificial neural network algorithm utilized in this study is not limited to the coastal sea level, and hence it can be extended to the detection model of erroneous values in various oceanic and atmospheric data.

• Journal of the Korean Chemical Society
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• v.66 no.5
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• pp.362-375
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• 2022

In this study, science teachers' NOS lessons were observed and the characteristics of the lessons were analyzed. Three science teachers who taught NOS in the 'Science Inquiry Experiment' developed under the 2015 revised curriculum participated in the study. Their NOS lessons were observed and interviews were conducted before and after lessons. The collected data were analyzed using analytical induction and constant comparative method. The analyses of the result revealed the teachers' naive views on NOS were also revealed during the lessons. There were some cases where they showed naive views during the lessons even if they showed informed views in the interviews. Although the domains of NOS taught by them were diverse, all of them taught 'tentativeness' and considered this an important goal. They tended to teach NOS with content related with their major, and teaching NOS was found to be deeply related to their major. In the activity where students learn NOS by inferring the unknown object, teachers disclosed the unknown object, which is unlike the rule of the activity. They thought that could help students' learning. At last, although they emphasized teaching NOS, they either did not assess NOS or assessed NOS in a limited way. Based on the results, some directions for teacher education and follow-up study are suggested.

• The Korean Society of Law and Medicine
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• v.22 no.4
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• pp.37-55
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• 2021

On March 19, 2021, the Korean Bioethics Association and related academic circles published a joint statement criticizing the partial revision of Infectious Disease Control And Prevention Act. However, according to the Bioethics And Safety Act of Korea, research conducted by the state or local governments for public welfare is excluded from human subjects research project. In addition, since the Korean legal system is not based on the dichotomy between research and surveillance, the discussion of the US Common Rule cannot be directly applied to Korea. For the harmonious operation of the state's duty to manage infectious diseases and the Institutional Review Boards, institutional alternatives should be prepared in consideration of the following issues. First, the related academic community should first pay attention to the problems of the current laws in Korea. Second, it should be understood that the state is carrying out many tasks without the consent of the parties in order to fulfill its duty to manage infectious diseases. Third, when presenting institutional alternatives, it is necessary to consider the feasibility of implementation in Korea. An in-depth discussion of the institutional alternatives by the Medical Law Society and other related academic circles is necessary.

• Journal of the Korea Society for Simulation
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• v.19 no.2
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• pp.73-80
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• 2010

A wireless sensor network which is deployed in hostile environment can be easily compromised by attackers. The selective forwarding attack can jam the packet or drop a sensitive packet such as the movement of the enemy on data flow path through the compromised node. Xiao, Yu and Gao proposed the checkpoint-based multi-hop acknowledgement scheme(CHEMAS). In CHEMAS, each path node enable to be the checkpoint node according to the pre-defined probability and then can detect the area where the selective forwarding attacks is generated through the checkpoint nodes. In this scheme, the number of hops is very important because this parameter may trade off between energy conservation and detection capacity. In this paper, we used the fuzzy rule system to determine adaptive threshold value which is the number of hops for the ACK packets. In every period, the base station determines threshold value while using fuzzy logic. The energy level, the number of compromised node, and the distance to each node from base station are used to determine threshold value in fuzzy logic.

• Analyses & Alternatives
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• v.2 no.1
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• pp.31-69
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• 2018

This study examines the role of science in resolving trade disputes. After the Great East Japan Earthquake of 11 March 2011 that not only jeopardized the people of Japan, but also put the safety of an entire region at risk, the Republic of Korea (Korea) has imposed import bans as well as increased testing and certification requirements for radioactive material on Japanese food products. Japan has challenged these restrictions at the World Trade Organizations Dispute Settlement Body (DSB). This study aims to explain how international trade agreements and previous DSB rulings have dealt with different scientific viewpoints provided by confronting parties. In doing so, it will contrast the viewpoints espoused by Korean and Japanese representatives, and then analyzes the most similar case studies previously ruled on by the DSB, including the case of beef hormones and the case of genetically modified crops including biotech corn, both between the United States and the European Communities (EC). This study finds that science is largely subordinate to national interests in the case of state decision-making within the dispute settlement processes, and science has largely been relegated to a supportive role. Due to the ambiguity and lack of truly decisive decisions in the Appellate Body in science-based trade disputes, this study concludes that the Appellate Body avoids taking a firm scientific position in cases where science is still inconclusive in any capacity. Due to the panel's unwillingness to establish expert review boards as it has the power to do, instead favoring an individual-based system so that all viewpoints can be heard, it has also developed a system with its own unique weaknesses. Similar to any court of law in which each opposing party defends its own interests, each side brings whatever scientific evidence it can to defend its position, incentivizing them to disregard scientific conclusions unfavorable to their position. With so many questions that can arise, combined with the problems of evolving science, questions of risk, and social concerns in democratic society, it is no wonder that the panel views scientific information provided by the experts as secondary to the legal and procedural issues. Despite being ruled against the EC on legal issues in two previous cases, the EC essentially won both times because the panel did not address whether its science was correct or not. This failure to conclusively resolve a debate over whose science is more scientific enabled the EC to simply fix the procedural issues, while continuing to enforce trade restrictions based on their scientific evidence. Based on the analysis of the two cases of disputes, Korea may also find itself guilty of imposing an unwarranted moratorium on Japan's fish exports, only to subsequently pass new restrictions on labelling and certification requirements because Japan may have much scientific evidence at its disposal. However, Korea might be able to create enough uncertainty in the panel to force them to rule exclusively on the legal issues of the case. This will then equip Korea, like the EC in the past, with a way of working around the ruling, by changing whatever legal procedure they need to while maintaining some, if not most, of its restrictions when the panel fails to address its case on scientific grounds.

• Korea Trade Review
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• v.43 no.1
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• pp.109-130
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• 2018

The cumulative standard is one of the criteria determining the origin of imported goods and is a provision that allows non-origin materials to be treated as origin goods when satisfying certain conditions. Regarding the Korea-Canada FTA, new cumulative standards were applied concerning cross accumulation of automobile products. It would benefit U.S. originating intermediate goods of HS code chapter 84, 85, 87, and 94 obtained into HS code heading from 8701 into 8706. We examine the effectiveness of crossover cumulative standards through the change in the import values of 84, 85, 87, 94, which are target items for cross cumulation. Only items designated for automobile parts were selected and analyzed. From the estimation results, significant changes appeared in 20 of the 35 items. It was found that the import amount increased significantly as of January 2015 or the rate of change in trend increases more than before. In addition, the estimation results show that Korean auto companies utilizing the cumulative standards through increased imports of auto parts form the U.S.

• Korea Trade Review
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• v.41 no.5
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• pp.15-39
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• 2016

Over the past couple of decades, we can see the emergence of a new lex mercatoria. It consists of international conventions or treaty, model laws and international principles. And such new lex mercatoria is driven by the international institutions such as UNCITRAL, UNIDROIT and ICC. The international convention and international principles in the field of international commercial transaction are considered : UN Convention on Contracts for the International Sale of Goods(CISG) and The UNIDROIT Principles(PICC Principles). The former is the statue law for the latter, and the latter sometimes supports the former as an interpretation and supplementation of CISG. So, the purpose of this article is to evaluate and investigate the current status of CISG and PICC Principles in terms of application and interpretation principles. The results are as follows. First, PICC are used for the interpretation and supplementation of international law such as CISG, but CISG is a law, not a rule. Second, CISG and PICC Principles are not often chosen when parties chose the law governing their contract. The parties very often chose a national law ; the number of the parties choosing CISG and PICC Principles as a governing law was very low.

• The Journal of KAIRB
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• v.2 no.1
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• pp.6-22
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• 2020

Purpose: Clinical studies require institutional review board (IRB) approval based on the ethical principle and regulations. While the number of clinical studies has been increased and diversified, duplicated IRB review for multi-center studies has become a major issue. Therefore, single IRB system has been suggested in revised Common Rule. This study aimed to identify and assess the current status of single IRB in Korea and the anticipated needs of single IRB from researchers and IRB member or administrators. Methods: We developed 14 questions including perceived advantages and disadvantages of single IRB, and anticipated problems. The online survey collected opinions on single IRB from researchers, IRB members and IRB administrators. We also interviewed five IRB administrators who have an experience of single IRB. Results: A total of 80 responses were analyzed in this study. Although efficiencies were suggested for the advantages of single IRB in terms of reducing burden of duplicated review, respondents also perceived that the different review criteria between single IRB and each IRB would be a major hurdle for adopting single IRB system. Therefore, the standardization of standard of procedures (SOP) and the standardization of IRB submission materials should be preceded. According to the small group experiences of single IRB in Korea, we also observed the similar anticipated problems of single IRB. Conclusion: Single IRB system has many advantages for conducting multi-center trial. However, many specialists still have a lot of concerns about introducing a single IRB system in Korea. Therefore, a gradual, step-by-step process for conducting a single IRB system in Korea will be needed. Many studies for improving currently suggested single IRB system and the improvement of awareness about the essential of single IRB system would be needed.