• KSII Transactions on Internet and Information Systems (TIIS)
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• 제18권5호
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• pp.1341-1368
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• 2024

The concept of privacy-preserving collaborative filtering (PPCF) has been gaining significant attention. Due to the fact that model-based recommendation methods with privacy are more efficient online, privacy-preserving memory-based scheme should be avoided in favor of model-based recommendation methods with privacy. Several studies in the current literature have examined ant colony clustering algorithms that are based on non-privacy collaborative filtering schemes. Nevertheless, the literature does not contain any studies that consider privacy in the context of ant colony clustering-based CF schema. This study employed the ant colony clustering model-based PPCF scheme. Attacks like shilling or profile injection could potentially be successful against privacy-preserving model-based collaborative filtering techniques. Afterwards, the scheme's robustness was assessed by conducting a shilling attack using six different attack models. We utilize masked data-based profile injection attacks against a privacy-preserving ant colony clustering-based prediction algorithm. Subsequently, we conduct extensive experiments utilizing authentic data to assess its robustness against profile injection attacks. In addition, we evaluate the resilience of the ant colony clustering model-based PPCF against shilling attacks by comparing it to established PPCF memory and model-based prediction techniques. The empirical findings indicate that push attack models exerted a substantial influence on the predictions, whereas nuke attack models demonstrated limited efficacy.

• 정보과학회 논문지
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• 제41권10호
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• pp.799-809
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• 2014

본 논문에서는 분산 컴퓨팅 환경에서 데이터 제공자들이 각자 소유한 데이터의 프라이버시는 보호하면서도 피어슨(Pearson) 상관계수와 스피어만(Spearman)의 순위상관계수를 안전하게 계산하는 해결책을 각각 제안한다. 분산 컴퓨팅 환경에서 마이닝(또는 데이터 분석)을 수행하기 위해서는 원본 데이터를 상대방에게 제공해야 한다. 그러나, 원본 데이터는 민감한 정보를 포함하는 경우가 많고, 이때 데이터 제공자(소유자)는 프라이버시 보호를 이유로 정확한 값을 직접 노출하기를 원하지 않는다. 본 논문에서는 분산 컴퓨팅 환경의 데이터 제공자들이 각자 소유한 데이터는 상대방에게 공개하지 않으면서 상관관계를 계산하는 문제, 즉 안전한 상관관계 계산(SCC: Secure Correlation Computation) 문제를 정형적으로 정의한다. 그리고, 임의 행렬 기반 안전한 스칼라 곱을 사용하여 피어슨 상관계수와 순위상관계수에 대한 SCC 문제를 해결하는 방법을 각각 제안한다. 제안한 해결책이 바르게 수행함을 보이기 위해, 정확성과 안전성을 정리로 제시하고 증명한다. 또한, 실험을 통해 제안한 기법이 수행 시간 측면에서도 실용적인 방법임을 보인다.

• 한국지능시스템학회논문지
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• 제15권1호
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• pp.65-68
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• 2005

유비쿼터스 환경에서는 프라이버시에 민감한 다양한 정보가 수집되고 이들이 통제되지 않은채 배포될 수 있기 때문에 프라이버시 보호가 필수적이다. 유비쿼터스 환경에서 프라이버시 보안을 위해 사용되는 대표적인 방법론의 하나인 익명(anonymity) 기반 기법은, 사용자가 새로운 서비스 영역에 참여할 때 가명(pseudonym)을 사용할 수 있도록 하여, 사용자의 신분을 노출시키지 않도록 하는 방법이다. 이 방법은 사용자의 신분을 보호하는데는 효과적이지만, 친구찾기 서비스, 위험지역경보, P2P통신 등 ID 기반의 서비스를 제공하기 어렵게 하는 단점이 있다. 이 논문에서는 익명기반의 프라이버스 보호 기법을 사용하는 유비쿼터스 환경에서 ID 기반의 서비스를 제공할 수 있도록 하는 시스템 구조를 제안한다.

• 정보보호학회논문지
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• 제29권3호
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• pp.685-692
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• 2019

스마트그리드는 기존의 단방향 전력 전송에서 나아가 양방향 정보 교환이 이루어지는 시스템으로 전력의 이동 및 소요량에 대한 실시간 파악이 가능하다. 전력 생산자는 전력 소모량 집계 결과로부터 향후 전력 생산량 예측이 용이하며, 사용자 또한 다수 전력원으로부터의 단위 사용 비용을 고려한 선택적 전력 사용 및 전력 절약 계획 수립이 용이해져 자원의 효율적 생산 및 사용을 가능하게 한다. 반면 자원의 사용 및 이동에 대한 실시간 정보 수집은 개인의 프라이버시를 침해할 수 있는 위험성을 내포하고 있다. 이러한 스마트그리드에서의 전력량 집계 과정에서 프라이버시 침해를 방지하기 위하여, 본 논문에서는 동형 암호화 기법을 활용함으로써 단순 합계를 포함한 복합 연산을 허용하는 유연하면서도 효율적인 전력량 집계 및 분석 기법을 제시한다.

• 기술사
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• 제45권1호
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• pp.49-53
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• 2012

It has been a common misconception that landscape architecture is a gardening, landscape gardening or planting. However, landscape architecture is entirely different from gardening, landscape gardening and planting when it comes to professional category. Landscape architecture is a interdisciplinary science to improve a quality of citizen's life through analysing social culture, psychological configuration, aesthetic characteristic and integrating them in human society. Today's landscape architecture is a interdisciplinary technology including ecological and artistic value to create most of outdoor space used by human through preserving nature and enhancing the environment. The field has been changed constantly in the flow of the period and social development as providing green network system, recreation area, ecological environment in the city.

• 한국대기환경학회지
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• 제27권6호
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• pp.681-691
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• 2011

The size distributions of smoke particles from fire are prerequisite for the studies on fire detection and adverse health effects. Above the flame of the fire, coagulation dominates and the smoke particles grow from 1 to 50 nm up to 100 to 3,000 nm, sizes ranging from the free-molecular regime to the continuum regime. The characteristics of the agglomeration of the smoke particles are well known, independently for each of the free-molecular and continuum regimes. However, there are not many systematic studies in the entire regime by the complexity of the mechanisms. The purpose of this work is to find the characteristics of the development of the size distribution of smoke particles by agglomeration in the entire size range covering the free-molecular regime, via transition regime, to the near-continuum and continuum regime for each variation of parameters such as fractal dimension, primary particle size and dimensionless coagulation time. In this work, the dynamic equation for the discrete-size spectrum of the particles was solved using a nodal method based on the modification of a sectional method. In the calculation, the collision frequency function for the entire regime, which is derived by using the concept of collision volume and general enhancement function, was applied. The self-preserving size distribution for the entire regime is compared with the ones for the free-molecular or continuum regimes for each variation of the parameters.

• 융합신호처리학회 학술대회논문집
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• 한국신호처리시스템학회 2005년도 추계학술대회 논문집
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• pp.167-170
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• 2005

Recently, filtering methods for attenuating noise while preserving image details are in progress actively. And SM(standard median) filter showed a great performance for noise removal in impulse noise environment but, it caused edge cancellation error. So, variable methods that modified SM(standard median) filter have been proposed, and CWM(center weighted median) filter is representative. Also, there are several methods to improve the efficiency based on min/max operation in term of preserving detail and filtering speed. In this paper, we managed a pixel corrupted by impulsive noise using min/max value of the surrounding band enclosing a pixel, and compared the efficiency with exiting methods in the simulation.

• 한국유기농업학회지
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• 제13권4호
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• pp.357-373
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• 2005

There is a controversy on developing or preserving Kwangduksan(Mt.) located in Cheonan and Asan. Kwangduksan has a grand scenery, many of cultural properties, and rare animals and plants like fireflies. So the citizens of Cheonan and Asan have recognized its cultural and ecological value as yet. In this study, an economic basis for preserving it was presented to prevent developing thoughtless for the environment. Preservation value of it was estimated about 44 billions by CVM. This result shows the environmental value of Kwangduksan is very great. If people feel importance of environmental resources more and more, this value of Kwangduksan will be greater and greater.

• 한국조경학회지
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• 제35권2호통권121호
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• pp.81-90
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• 2007

This study used the functions for public benefits as a standard for evaluating Green Tourism. By referring to the existing literature, the "function of building emotion", the "function of providing a natural environment", the "function of preserving traditional cultures", and the "function of maintaining the local community" have been selected as the measuring variables. Detailed sub-variables of each function were prepared to examine and analyze the recognition of these are the part of Green Tourists. The Green Tourists of Yangsuri in Yangpyeong, Sinnonri in Yangpyeong, and Jurokri in Yeoju participated in the survey for which 13 variables were used as measurement. The results are as follows: First, Green Tourists recognize farm villages as places for rest and relaxation and they laid great importance on the function of providing access to the natural environment. Secondly, out of the 13 measurement variables, "beautiful scenery in farm village", "making a contribution to village income", and "trust in agricultural products" greatly influenced the overall evaluation of Green Tourism. Thirdly, regarding the relationship between the functions for public benefits and Green Tourism, it was found that "facilities and activities for experiencing farming", "facilities for rest", and "beautiful scenery in farm villages" are closely related to building the emotion experienced in these villages, and that "cultivating environmentally-friendly agricultural products" and "beautiful scenery in farm village" are closely related to the function of providing access to the natural environment.

• 한국주거학회논문집
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• 제1권1호
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• pp.65-76
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• 1990

Sugok Villiage. of the prospective flooded villiages for building Im Ha Dam, is selected as the studied place. Primarily, the purpose of this study is invested, recerded about traditional living environment, and then searched to find out possibilites on the context of the inheritance of analyzing about life contents and space. The result of this study are as follows:1) In composition of living environment, thinking view on confucianism and living view on folk beliefs are considered as important element2) Hierarchy of life environment is appeared of above and below space.(focused on JONG KA) and inner and outer space(boarded on pine forest) on the other hand according to living territory life environment can be divided into five territories.3) Confucian ideas, social status, folk beliefs and economics has been affected about formation of individual life. Accordingly, I believe that true inheritance of traditional culture was, through preserving mental contents as well as physical contents, possible.