• Smart Structures and Systems
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• 제4권2호
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• pp.233-245
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• 2008

For historical masonry structures existing in the Mediterranean area, structural strengthening is of primary importance due to the continuous earthquake threat that is posed on them. Proper retrofitting of historical structures involves a thorough understanding of their structural pathology, before proceeding with any intervention measures. In this paper, a methodology is presented for the evaluation of the actual state of historical masonry structures, which can provide a useful tool for the seismic response assessment before and after the retrofitting. The methodology is mainly focused on the failure and vulnerability analysis of masonry structures using the finite element method. Using this methodology the retrofitting of historical structures with innovative techniques is investigated. The innovative technique presented here involves the exploitation of Shape Memory Alloy prestressed bars. This type of intervention is proposed because it ensures increased reversibility and minimization of interventions, in comparison with conventional retrofitting methods. In this paper, a case study is investigated for the demonstration of the proposed methodologies and techniques, which comprises a masonry Byzantine church and a masonry Cistern. Prestressed SMA alloy bars are placed into the load-bearing system of the structure. The seismic response of the non-retrofitted and the retrofitted finite element models are compared in terms of seismic energy dissipation and displacements diminution.

• Smart Structures and Systems
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• 제26권1호
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• pp.1-10
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• 2020

Turkey is a transcontinental country located partly in Asia and partly in Europe, and hosted by diverse civilizations including Hittite, Urartu, Lydia, Phrygia, Pontius, Byzantine, Seljuk's and Ottomans. At various times, these built many historic monuments representing the most significant characteristics of their civilizations. Today, these monuments contribute enormously to the esthetic beauty of environment and important to many cities of Turkey in attracting tourism. The survival of these monuments depends on the investigation of structural behavior and implementation of needed repairing and/or strengthening applications. Hence, many countries have made deeper investigations and regulations to assess their monuments' structural behavior. This paper presents the dynamic behavior investigation of a monumental masonry mosque, the "İskenderpaşa Mosque" in Trabzon (Turkey), by performing an experimental examination with non-destructive testing. The dynamic behavior investigation was carried out by determining the dynamic characteristic called as natural frequencies, mode shapes and damping ratios. The experimental dynamic characteristics were extracted by Operational Modal Analysis (OMA). In addition, Finite Element (FE) model of masonry mosque was constructed in ANSYS software and the numerical dynamic characteristics such as natural frequencies and mode shapes were also obtained and compared to experimental ones. The paper aims at presenting the non-destructive testing procedure of a masonry mosque as well as the comparison of experimental and numerical dynamic characteristics obtained from the mosque.

• Journal of Information Processing Systems
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• 제16권2호
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• pp.301-317
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• 2020

An enterprise patch-management system (PMS) typically supplies a single point of failure (SPOF) of centralization structure. However, a Blockchain system offers features of decentralization, transaction integrity, user certification, and a smart chaincode. This study proposes a Hyperledger Fabric Blockchain-based distributed patch-management system and verifies its technological feasibility through prototyping, so that all participating users can be protected from various threats. In particular, by adopting a private chain for patch file set management, it is designed as a Blockchain system that can enhance security, log management, latest status supervision and monitoring functions. In addition, it uses a Hyperledger Fabric that owns a practical Byzantine fault tolerant consensus algorithm, and implements the functions of upload patch file set, download patch file set, and audit patch file history, which are major features of PMS, as a smart contract (chaincode), and verified this operation. The distributed ledger structure of Blockchain-based PMS can be a solution for distributor and client authentication and forgery problems, SPOF problem, and distribution record reliability problem. It not only presents an alternative to dealing with central management server loads and failures, but it also provides a higher level of security and availability.

• 한국의상디자인학회지
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• 제19권1호
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• pp.55-70
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• 2017

This study researched transition process of fur costume from ancient times to 20th century, extracted esthetic characteristics, and then understood how the esthetic characteristics appear in the recent fur collection. The result is as follows. First, magical meaning was revealed on leopard fur that ancient chief priests wore on top of shenti to symbolize immorality and fur tunics to which christian symbol was added in Byzantine. During middle age and the Renaissance, extravagance appeared on sable and amin jackets that the noble decorated to show off their high status. During the rococo age and mid-20th century, sensuality and elegance appeared on the fur dresses that the female body was emphasized. Second, in recent collection, extravagance appeared on over-sized and voluminous fox-coat, sexsuality and elegance were revealed through mink-dresses and jackets with soft touch and gloss that curved-silhouette was emphasized. In addition, practicality and functionality were shown through short length and light, soft material, and activeness was in the mink jacket to which functional elements such as zippers and rubber were added. To pursue uniqueness and fun, fox jackets were made with over-sized vivid green color. Besides, abnormality and vulgarness appeared through the fashion with abnormal and distracted images with ambiguous forms and new processing methods applied.

• 한국융합학회논문지
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• 제10권11호
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• pp.41-46
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• 2019

최근에 작업 증명(PoW) 블록체인 합의 알고리즘들이 에너지 낭비, 확장성 부족 등의 문제점들이 나타나면서 비잔틴 장애 허용(BFT) 계열 합의 알고리즘들이 주목을 받고 있다. BFT 계열 합의 알고리즘들의 큰 특징 중 하나는 검증자 집합을 형성하여 그 안에서 합의를 이루는 것이다. 본 논문에서는 BFT 계열 합의 알고리즘들 중에서도 알고랜드, 스텔라, 이오스의 검증자 집합 형성 방법들의 확장성, 목표가 설정된 공격 가능 여부, 시빌 공격 가능 여부에 대해서 비교, 분석하였다. 또한 데이터 분석을 통한 각 검증자 형성 방법들의 문제점들을 발견하였고, 해당 합의 알고리즘들은 공통적으로 소수의 권력 있는 노드들이 전체 시스템을 지배하는 중앙화 현상이 나타남을 밝혔다.

• 정보보호학회논문지
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• 제32권5호
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• pp.899-914
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• 2022

블록체인 기반 탈중앙 서비스는 참여자들의 합의에 기반하여 시스템을 운영함으로써 중앙화된 서버 없이도 신뢰 할 수 있는 서비스를 사용자에게 제공할 수 있다. 참여자들은 디지털서명 메커니즘을 사용하여 블록체인과 상호작용 할 수 있지만 개인키 관리와 관련된 이슈는 여전히 해결되지 않는 문제로 남아있다. NIST SP800-57 암호키 관리 권고안 등에서는 사용자의 개인키 관리에 관한 내용을 기술하고 있지만, 이는 탈중앙 서비스 환경을 고려하지 않았기에 블록체인 환경에 적용하기에는 적절하지 않다. 본 논문에서는 개인키 관리와 관련된 지갑 애플리케이션의 기능을 정의하고 NIST SP800-57을 반영한 블록체인 개인키 관리 방안과 이를 만족하기 위한 관련 기술을 제시한다. 마지막으로 논문에서 정의한 내용을 바탕으로 퍼블릭 블록체인에서 일반 사용자를 대상으로 하는 개인키 관리 가이드라인을 제안한다.

• 스마트미디어저널
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• 제12권9호
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• pp.95-102
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• 2023

개인정보의 활용 가치가 높아짐에 따라, 개인정보를 제공하는 방법에 대한 논의가 활발하나, 개인정보 활용을 위해 기관에서 필요로 하는 정보는 필요 이상의 정보가 노출되고 있다. 따라서 개인정보 보호의 문제점과 한계를 극복하기 위한 개인의 프라이버시 보호는 필수적이다. 본 연구에서는 개인정보의 중앙집중형 ID 관리(Centralized Identity Management)방법의 문제와 한계를 극복하고, 정보 소유자 스스로 자신의 개인정보를 관리하고 선택적으로 제공하는 탈중앙화 정보 관리(Decentralized Identity Information Management)모델을 제시하고, 실험을 통하여 PBFT 합의 알고리즘에서 스마트 개인정보 제공 시스템(SPIPS: Smart Personal Information Provision System)을 구현하여 개인 정보의 우수성을 보인다.

• 대한가정학회지
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• 제11권3호
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• pp.247-261
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• 1973

In the past, what we call "fashion" was monopolized by only a small highly privileged group of individuals. To-day, we know that fashion field has become progressive democratization of taste not only in clothing, but in all expressions of contemporary living, from automobiles to refrigerators. So, we can find out how wonderful it is that our recent fashionable history was changed so fast. Whatever highly characteristic costume may be in the former, the way people dress was the reflection of their contemporary lives as well as their political status, economics, cultures, arts religions, so that a history of fashion is a history of life. Now, that categorical silhouettes make an exclusion across centuries of past history into the world of aesthetics, particularizes following ; symbolic voluminous toga of Roman authority, the religious but gorgeous Byzantine tunic, extravagant vertical bell-skirt of the Renaissance, the romantic Rococo style, the elegant crinoline and the bustle of the Cul de Paris of the nineteenth. It came true that women was intoxicated ostentations and elegances, since they had on ornamently costume which bear some relationship to the more formal Co-stesy, till the beginning of the twentieth. As Jonney Ironside said, "Nowadays, those exessive ornamentations and cumbersome design hardly belong to a civilization run by machines and in a hurry". These were once a sign of wealth and class ; at the beginning of the twentieth it was disappearing step by step. What is the reason\ulcorner At the end of the nineteenth, the emancipation of women, the movement of the Art Nouveau and the opening of the ready-made, have influenced on modern style, directly or indirectly. Finally, democratically popular costume was caused by fighting against the masculine prejudice excluded them from activities.hem from activities.

• 한국의류학회지
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• 제16권4호
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• pp.357-369
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• 1992

The purpose of this study was to clarify the relationship between the Ideal Beauty of Body and the Form of Dress, and to analyze its historical perspectives. First of all, the concept of the Ideal Beauty of Body, the definition of Dress Form, and the method and system to clarify Dress Form were depicted. Based on this frame work, the Form of Dress related to the Ideal Beauty of Body was described historically. For this purpose, documentary research were conducted and representative photography and paintings were used. The analysis was limited to the female one-Piece dress from Ancient Egypt, Greece, Rome, Byzantine, Gothic, Renaissance, Baroque, Rococo, Naoclassicism, and to Romanticism. The results were as follows: 1. The Ideal Beauty of Body was found to be different throughout history and to be intimate- ly linked with fashionable dress. 2. The Form of Dress consisted of four basic components: The form of body itself, the form of clothing itself, the method of wearing, and the relationship between body and clothing. 3. The standards for classification of body form were body structure, body type, body proportion, posture, and movement. Clothing form was generally classified into flat type (unstructured type) and three dementional type (structured type); flat type was subclassified into draped type and tunic type. The method of wearing was classified into attached type, tying-up type, wrap·around type, pull-over type, open type and plastistic type. The relationship between body and clothing after wearing was generally classified into body priority type and clothing priority type. The clothing priority type was further divided into body exaggeration type and body concealment type; Body exaggeration type was further divided into upward type, downward type, forward type, backward type, right type and constriction type. 4. The pursuit of venus coelestis, metaphysical body part, ectomorphic body type, flat type clothing, body priority type; the pursuit of Venus Naturalis, physical body part, endomorphic body type, three dementional type clothing, clothing priority type proved to be closely related respectively by the historical study on the Ideal Beauty of Body and the Form of Dress.

• 스마트미디어저널
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• 제9권1호
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• pp.9-15
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• 2020

블록체인은 데이터의 투명성 및 보안성이 뛰어난 분산공유원장으로써 핵심기술인 합의 알고리즘을 통하여 참여 노드에 동일한 데이터를 순차적으로 공유할 수 있도록 한다. 이러한 블록체인 기술의 특징을 활용하고자 최근 기업 및 공공기관을 중심으로 블록체인을 적용하려는 시도가 증가하고 있다. 본 논문에서는 분산 네트워크와 같은 비동기 네트워크 환경에서 활용되는 프라이빗 블록체인의 합의 알고리즘인 PBFT를 수정하여 네트워크 통신비용 및 합의 안정성을 고려한 수정된 PBFT를 제안하였다. 수정된 PBFT는 노드 간 신뢰가 보장된 비동기 네트워크 환경의 특징을 감안하여 클라이언트의 요청 검증에 대하여 기존의 전체 참여 방식을 개선하여 2/N의 Leader(리더)를 통한 합의와 인증을 제안하였다. 해당 과정에서 발생되는 브로드캐스트 과정의 간소화를 통하여 합의를 위한 최소 노드 수 유지가 가능하였으며 네트워크 통신을 위한 효율적 비용관리가 가능하다.