• 한국정보기술학회논문지
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• 제17권5호
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• pp.129-136
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• 2019

센서 등 많은 IoT 디바이스들은 화면출력 및 입력장치 등이 결여된 경우가 많아 개인정보보호법이나 GDPR 등에서 요구하는 개인정보수집 동의 절차를 만족시키기 어려워, 해당 비즈니스 분야 발전에 법적인 걸림돌로 작용하고 있다. 본 연구에서는 법적인 요건을 만족하는 IoT 시스템에서의 개인정보수집 동의 절차를 설계한다. 설계된 방식에서는 먼저 사용자의 개인정보가 암호화된 상태로 수집되며, 이후 데이터 수집 서버와 사용자 에이전트 사이에 개인정보 수집을 기반으로 연관을 맺음으로서 암호화된 내용을 복호화 한다. 이러한 연관 동의 과정에서 사용자 에이전트는 데이터 수집 서버의 개인정보수집 약관 등을 이해하고 복호화키를 제공한다. IoT 시스템에서의 이러한 방식의 개인정보수집 동의 절차는 GDPR 등의 법령에서 정하는 투명성, 자율성 등의 요건을 만족함으로서 개인정보를 취급하는 IoT 비지니스 분야의 발전에 크게 기여할 것으로 판단된다.

• International Journal of Computer Science & Network Security
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• 제21권1호
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• pp.143-151
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• 2021

The enormous prevalence of transferring official confidential digital documents via the Internet shows the urgent need to deliver confidential messages to the recipient without letting any unauthorized person to know contents of the secret messages or detect there existence . Several Steganography techniques such as the least significant Bit (LSB), Secure Cover Selection (SCS), Discrete Cosine Transform (DCT) and Palette Based (PB) were applied to prevent any intruder from analyzing and getting the secret transferred message. The utilized steganography methods should defiance the challenges of Steganalysis techniques in term of analysis and detection. This paper presents a novel and robust framework for color image steganography that combines Linear Congruential Generator (LCG), simulated annealing (SA), Cesar cryptography and LSB substitution method in one system in order to reduce the objection of Steganalysis and deliver data securely to their destination. SA with the support of LCG finds out the optimal minimum sniffing path inside a cover color image (RGB) then the confidential message will be encrypt and embedded within the RGB image path as a host medium by using Cesar and LSB procedures. Embedding and extraction processes of secret message require a common knowledge between sender and receiver; that knowledge are represented by SA initialization parameters, LCG seed, Cesar key agreement and secret message length. Steganalysis intruder will not understand or detect the secret message inside the host image without the correct knowledge about the manipulation process. The constructed system satisfies the main requirements of image steganography in term of robustness against confidential message extraction, high quality visual appearance, little mean square error (MSE) and high peak signal noise ratio (PSNR).

• 한국환경과학회지
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• 제30권3호
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• pp.195-206
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• 2021

Contaminated marine sediment is a secondary pollution source in the coastal areas, which can result in increased nutrients concentrations in the overlying water. We analyzed the nutrients release characteristics into overlying water from sediments and the interaction among benthic circulation of nitrogen, phosphorus, iron, and sulfur were investigated in a preset sediment/water column. Profiles of pH, ORP, sulfur, iron, nitrogen, phosphorus pools were determined in the sediment and three different layers of overlying water. Variety types of sulfur in the sediments plays a significant role on nutrients transfer into overlying water. Dissimilatory nitrate reduction and various sulfur species interaction are predominantly embodied by the enhancing effects of sulfide on nitrogen reduction. Contaminant sediment take on high organic matter, which is decomposed by bacteria, as a result promote bacterial sulfate reduction and generate sulfide in the sediment. The sulfur and iron interactions had also influence on phosphorus cycling and released from sediment into overlying water may ensue over the dissolution of ferric iron intercede by iron-reducing bacteria. The nutrients release rate was calculated followed by release rate equation. The results showed that the sediments released large-scale quantity of ammonium nitrogen and phosphate, which are main inner source of overlying water pollution. A mechanical migration of key nutrients such as ammonia and inorganic phosphate was depicted numerically with Fick's diffusion law, which showed a fair agreement to most of the experimental data.

• Computers and Concrete
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• 제27권2호
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• pp.163-173
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• 2021

In this paper, the parameters of haunch height, reinforcement ratio and site condition were evaluated for the influence on the seismic performance of a composite precast fabricated utility tunnel by shaking table test and numerical simulation. The dynamic response laws of acceleration, interlayer displacement and steel strain under unidirectional horizontal seismic excitation were analyzed through four specimens with a similarity ratio of 1:6 in the test. And a numerical model was established and analyzed by the finite element software ABAQUS based on the structure of utility tunnel. The results indicated that composite precast fabricated utility tunnel with the good anti-seismic performance. In a certain range, increasing the height of haunch or the ratio of reinforcement could reduce the influence of seismic wave on the utility tunnel structure, which was beneficial to the structure earthquake resistance. The clay field containing the interlayer of liquefied sandy soil has a certain damping effect on the structure of the utility tunnel, and the displacement response could be reduced by 14.1%. Under the excitation of strong earthquake, the reinforcement strain at the side wall upper end and haunches of the utility tunnel was the biggest, which is the key part of the structure. The experimental results were in good agreement with the fitting results, and the results could provide a reference value for the anti-seismic design and application of composite precast fabricated utility tunnel.

• International Journal of Naval Architecture and Ocean Engineering
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• 제13권1호
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• pp.379-395
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• 2021

For the complicated structural details in ships and offshore structures, the traditional hotspot stress approaches are known to be sensitive to the element variables of element topologies, sizes, and integration schemes. This motivated to develop a new approach for predicting reasonable hotspot stresses, which is less sensitive to the element variables and easy to be implemented the real marine structures. The three-point bending tests were conducted for the longitudinal attachments with the round and rectangular weld toes. The tests were reproduced in the numerical simulations using the solid and shell element models, and the simulation technique was validated by comparing the experimental stresses with the simulated ones. This paper considered three hotspot stress approaches: the ESM method based on surface stress extrapolation, the Dong's method based on nodal forces along a weld toe, and the proposed method based on nodal forces perpendicular to an imaginary vertical plane at a weld toe. In order to study the element sensitivities of each method, 16 solid element models and 8 shell element models were generated under the bending and tension loads, respectively. The element sensitivity was analyzed in terms of Stress Concentration Factors (SCFs) in viewpoints of two statistical quantities of mean and bias with respect to the reference SCFs. The average SCFs predicted by the proposed method were remarkably in good agreement with the reference SCFs based on the experiments and the ship rules. Negligibly small Coefficients of Variation (CVs) of the SCFs, which is measure of statistical bias, were drawn by the proposed method.

• 한국지반공학회논문집
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• 제22권4호
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• pp.61-71
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• 2006

본 논문에서는 유효응력모델을 이용하여 포화된 사면의 동적거동에 관한 연구를 수행하였다. 수치해석에는 저자가 개발한 연성 유효응력모델인 UBSSAND모델을 이용하였으며, 이 모델은 초기전단응력이 수평면에 작용하는 경우와 작용하지 않는 경우를 포함한 반복 직접단순전단시험 자료를 이용하여 검증하였다. 검증된 모델은 느슨한 Fraser River 모래로 성형된 사면을 가진 원심모형모델의 동적거동을 예측하였다. 예측된 과잉간극수압, 가속도 및 변위를 계측치와 서로 비교하였으며, 예측치와 계측치는 비교적 서로 잘 일치하였다. 전단응력도의 응력전환형태는 초기전단응력과 반복전단응력의 크기에 따라 달라지며, 이는 지진시 포화된 사면의 안정해석에 아주 중요한 역할을 하고 있음을 알 수 있었다. 전단응력도의 응력전환이 발생하지 않을 경우에 사면근처의 모래는 낮은 유효응력 구속압과 그에 따른 팽창성으로(부의 과잉간극수압발생) 유효응력이 증가하여, 동적하중 하의 사면의 변위를 저지하였다. 이와 같은 유효응력모델은 액상화를 고려한 지반구조물의 내진해석에 유용하게 사용될 수 있다.

• 무역학회지
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• 제41권1호
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• pp.159-186
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• 2016

본 연구는 1991-2012년간 동아시아 국가 간 산업별 부품무역의 비교우위를 분석하여, 동아시아 FTA 체결 시 예상되는 무역과 생산분할 구조를 분석한다. 분석기간 중 동아시아 내 부품무역의 상호의존도는 지속적으로 증가하여 왔으며, 동아시아 FAT 체결 시 구조적 변화가 없다면 한국과 일본이 동아시아 내 전기 및 전자기기, 수송기기 부품수출을 더 강화하고, 중국과 ASEAN이 최종재를 수출하는 구조는 유지될 것으로 예상된다.

• 융합보안논문지
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• 제23권2호
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• pp.95-102
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• 2023

본 연구의 목적은 최근의 장교 지원율 하락에 따른 장교획득 수준의 시대적 심각성을 반영하여 장교 양성과정에서 핵심적인 역할을 수행하고 있는 일반대학 군사학과의 운영 수준을 상대적인 평가, 분석을 바탕으로 실증적 연구를 통하여 확인해 보고 개선을 위한 의미있는 결과를 확인하였다. 육군과 협약, 준협약을 통하여 운영되고 있는 일반대학 군사학과는 11개이며 대학별 군사학과 운영을 위해 투입되는 자원입력과 성과관점에서 자료포락분석법(DEA, Data Envelopment Analysis)을 적용하여 상대적인 효율성을 분석하고 개선을 위한 구체적인 방향을 확인하였다. 운영 효율성 분석결과, 11개 DMU 중에서 BCC모델의 경우 6개 대학이 효율적인 것으로 나타났고 자료포락분석 방법을 통하여 효율적, 비효율적인 집단에 대한 구분을 통해 평가결과를 확인해 볼 수 있었다. 본 연구는 상대적인 효율성을 평가하는데 여러 개의 평가요소를 한꺼번에 반영하여 초과, 부족한 부분을 나타내는 DEA-Additive 모델을 통해 비교대상 대학 군사학과들의 상대적인 측면에서 효율성을 확인하고 발전을 위한 구체적인 정보를 확인한다는 점에서 실용적 가치가 있을 수 있다.

• 보건의료기술평가
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• 제1권1호
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• pp.22-26
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• 2013

Objectives: Balancing benefits and risks through the drug life cycle has been discussed for many decades. The objective of this study was to review the processes and tools currently proposed for benefit-risk assessment of medicinal drugs. It aimed to establish scientific and efficient drug safety management system based on the synthetic analysis of benefit-risk evidence. Methods: We conducted a review of exiting literatures published by regulatory agencies or initiatives. Not only quantitative methodologies but also qualitative method were compared to understand their key characteristics for the benefit and risk assessment of drugs. Results: Recently, benefit-risk assessments have more structured approaches to decision making as part of regulatory science. Regulatory agencies such as European Medicines Agency, FDA have prepared plans to apply benefit-risk assessment to regulatory decision making. Also many initiatives such as IMI (Innovative Medicine Initiative) have conducted research and published reports about benefit-risk assessment. For benefit-risk assessment, four kinds of methods are necessary. Frameworks such as BRAT (Benefit Risk Action Team) framework, PrOACT-URL provide guidance for the whole process of decision-making. Metrics are measurements of risk benefit. The estimation techniques are methods to synthesis and combine evidences from various sources. The utility survey techniques are necessary to explicit preferences of various outcome from stakeholders. Conclusion: There is the lack of widely accepted, validated model for benefit-risk assessment. Nor there is an agreement among academia, industry, and government on methods for the quantitative valuation. It is also limited by available evidence and underlying assumptions. Nevertheless, benefit-risk assessment is fundamental to improve transparency, consistency and predictability for decision making through the structured systematic approaches.

• Korean Journal of Radiology
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• 제25권4호
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• pp.331-342
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• 2024

The Asian Society of Cardiovascular Imaging-Practical Tutorial (ASCI-PT) is an instructional initiative of the ASCI School designed to enhance educational standards. In 2021, the ASCI-PT was convened with the goal of formulating a consensus statement on the assessment of coronary stenosis and coronary plaque using coronary CT angiography (CCTA). Nineteen experts from four countries conducted thorough reviews of current guidelines and deliberated on eight key issues to refine the process and improve the clarity of reporting CCTA findings. The experts engaged in both online and on-site sessions to establish a unified agreement. This document presents a summary of the ASCI-PT 2021 deliberations and offers a comprehensive consensus statement on the evaluation of coronary stenosis and coronary plaque in CCTA.