• 제목/요약/키워드: one-way function.

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일시적 비사용과 사용 간의 동태적 상태 변화에 대한 연구: 근거이론방법론에 의한 접근 (Dynamic State Changes between Temporary Non-Use and Use: Approached by Grounded Theory Methodology)

  • 이웅규
    • 한국정보시스템학회지:정보시스템연구
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    • 제28권4호
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    • pp.359-375
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    • 2019
  • Purpose The purpose of this study is to investigate the nature of temporal non-use, namely, the type of temporal non-use and the dynamic relationships between temporary non-use and use by expanding the model of dynamic state transition of non-use which is proposed by the previous study. Design/methodology/approach This study adopted grounded theory methodology as a research methodology. Fifteen university students were interviewed for open coding and for selected coding which leads the research model ten students were interviewed. Findings Based on the coding, the types of use were divided into interactive use and one-way use, and the types of temporal use were classified into temporal non-use in which use is intended and temporal non-use in which use is not intended. The dynamic transition model is presented for each type of use and temporalnon-use, and an integrated model that combines them is presented. This study found the following four things: First, all non-use can be temporal Second, there are different types of temporal non-use. Third, the pattern of use is not just one, but new patterns will continue to emerge. Fourth, we found a change in the function of SNS.

A novel method for predicting the swelling potential of clay-bearing rocks

  • Moosavi, Mahdi;Ghadernejad, Saleh
    • Geomechanics and Engineering
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    • 제27권6호
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    • pp.615-626
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    • 2021
  • The main objective of this study is to present a fast and reliable approach to predict the swelling potential of clay-bearing rocks. Investigations showed that there is a good correlation between the swelling potential of a rock and its desire to absorb water due to its clay content which could be measured using the "Contact Angle" test as one of the most common ways to determine the wettability. In this test, the angle between a water drop and the flat rock surface on which it rests is measured. The present method is very fast and returns repeatable results and requires minimal sample preparation. Only having a saw-cut surface of a sample with any shape is all one needs to perform this test. The logic behind this approach is that the swelling potential of a rock is a function of its mineral content and molecular structure, which are not only distributed in the bulk of the sample but also reflected on its surface. Therefore, to evaluate swelling behavior, it is not necessary to wait for a sample to get wet all the way to its "internal structure" (which, due to the low permeability of clay-bearing rocks, is very slow and time-consuming). Instead, one can have a good sense of swelling potential by studying its surface. Parametric studies on the effect of moisture content, porosity, and surface roughness on the contact angle measurements showed that using a saw-cut oven-dried sample is a convenient way to evaluate the swelling potential by this method.

현대복장 기능의 다양화 현상에 관한 연구 (A Study on the Phenomenon of Diversification of Modern Clothing)

  • 이난희
    • 한국의상디자인학회지
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    • 제4권2호
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    • pp.181-196
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    • 2002
  • The functions of the clothing have been changed rapidly in modern society. That means people want to show oneself strongly by the clothing. In other words, the social aspect of the clothing's function which is the expression of own's personality and satisfaction one's desire is emphasized. This study is aimed at taking a look at the functions of modern clothing. The modern clothing has the various functions which are related to the changing of the social system. The result of the study are as follows: With the differentiation of society and institutionalization, the clothing is recognized as the medium which shows one's status and is restricted by people. In modern society as mass society, the system of the social position collapsed. People has the inclination to express own's consciousness, personality and existence intensely. Also, the functions of clothing became diverse. That means the clothing is influenced by the human's consciousness, a sense of values and became the medium which reflects the people's life. This change of the costume means the clothing focus on the functional factor of the free-style clothing getting out of rational value. Therefore, the change of clothing is not the change of the design but the change of value of the clothing, one's way of thinking about the clothing, the change of human life in whole society and the culture. With the changing way of life, the change of the clothing has the system in which the design changes. Therefore, I found that the we have to take a look not the change of the factors which influence the fashion but the functions of the clothing itself.

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주행중인 자동차 환경에서의 음성인식 연구 (A Study on Speech Recognition in a Running Automobile)

  • 양진우;김순협
    • 한국음향학회지
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    • 제19권5호
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    • pp.3-8
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    • 2000
  • 본 논문은 주행중인 자동차 환경에서의 음성인식에 대하여 연구하였다. 여기에서 사용한 기준패턴(reference pattern)은 DMS(Dynamic Multi-Section)이며, 인식율을 높이기 위하여 2모델을 제안하였다. 또한 가변적인 차량의 잡음환경에 강인하기 위하여 일반주행(80km/h 이내), 고속주행(80km/h 이상)등으로 나누었으며 차량의 잡음에 따라 자동으로 선택하도록 하였다. 음성의 특징 벡터와 인식 알고리즘은 PLP(Perceptual Linear Predictive) 13차와 OSDP(One-Stage Dynamic Programming)를 사용하였다. 그리고 핸드폰을 사용하는 운전자의 안전을 위하여 음성으로 전화를 걸 수 있도록 하는 전화번호 등록 및 제어기능의 Voice Dialing 기능을 추가하였다. 실험결과 주행중인 자동차 환경에서 자주 사용되는 차량 편의장치 제어명령 33개에 대하여 중부, 영동 고속도로(시멘트 도로 80km/h이상)에서 남성 화자독립 89.75%의 인식율을 구하였으며, 경부고속도로(아스팔트 도로 80km/h이상)에서는 남성화자독립 92.29%의 인식율을 구하였다.

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MANET 환경에서 중복 주소 탐지에 대한 DoS 공격을 방지하는 보안 기법과 성능 평가 (A Security method and Performance evaluation of preventing DoS attack against DAD in MANET)

  • 임정미;박창섭
    • 한국멀티미디어학회논문지
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    • 제12권8호
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    • pp.1099-1108
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    • 2009
  • MANET(Mobile Ad Hoc Network) 상에서 IP주소 할당에 관한 연구는 특정 노드가 다른 노드들의 IP주소를 모니터링 하여 할당하는 Stateful 방식과, 노드 스스로 IP주소를 생성하는 Stateless 방식이 있다. MANET 상의 노드들은 이동성과 제한된 자원의 특성으로 노드 스스로 IP 주소를 생성하는 Stateless 방식이 더 적합하다. 그러나, Stateless 방식에서는 중복되지 않는 주소를 할당하기 위한 DAD(Duplicate Address Detection)과정이 필요하고, 이 과정에서 DoS(Denial of Service) 공격이 발생할 수 있다. 본 논문에서는, MANET의 특성에 맞춰 계산량이 적게 드는 일방향 해쉬 함수를 이용하여, DAD과정에서 발생할 수 있는 DoS 공격을 방지하는 보안 기법을 제안한다. 그리고, NS2를 이용하여 기존의 서명을 이용한 CGA(Cryptographically Generated Addresses) 방식과 비교, 성능평가 한다.

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SHA-3 해쉬함수 소비전력 특성 분석 및 저전력 구조 기법 (Analysis on Power Consumption Characteristics of SHA-3 Candidates and Low-Power Architecture)

  • 김성호;조성호
    • 한국정보통신학회논문지
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    • 제15권1호
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    • pp.115-125
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    • 2011
  • 해쉬함수는 데이터와 명령에 대한 위변조를 방지와 같은 무결성 제공하거나 서명이나 키 분배 등 다양한 보안 프로토콜에서 서명 및 인증, 키 분배 목적으로 많이 사용되는 일방향성 함수(one-way function)다. 2005년 Wang에 의해 암호학적 취약성이 발견되기까지 해쉬함수로는 SHA-1이 많이 사용 되었다. SHA-1의 안전성에 문제가 생기게 되자 NIST(National Institute of Standards and Technology)에서는 암호학적으로 안전한 새로운 해쉬함수 개발 필요성을 느껴 2007년 11월에 공개적으로 새로운 해쉬함수에 대한 공모를 시작했으며, SHA-3로 명명된 새로운 해쉬함수는 2012년 최종 선정될 예정이다. 현재 제안된 SHA-3 함수들에 대한 암호학적인 특성과 하드웨어로 구현했을 때의 하드웨어 복잡도, 소프트웨어로 구현했을 때의 성능 등에 대한 평가가 이뤄지고 있다. 하지만 하드웨어로 구현된 해쉬함수의 중요한 특성 평가 척도(metrics)인 소비 전력 특성에 대한 연구는 활발히 이뤄지지 않고 있다. 본 논문에서는 제안된 SHA-3 해쉬함수를 하드웨어로 구현했을 경우의 소비 전력 특성을 분석하고 소비전력 특성 분석 결과를 토대로 SHA-3 해쉬함수 중에서 새로운 SHA-3 해쉬함수로 선정될 확률이 높은 Luffa 함수에 대한 저전력 구조를 제안한다. 제안된 저전력 구조는 기존의 Luffa 하드웨어보다 약 10% 정도 적은 전력을 소비함을 보인다.

연령에 따른 손기능의 변화 (The Age-Related Change of Hand Function)

  • 김용수;박래준;김진상
    • The Journal of Korean Physical Therapy
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    • 제6권1호
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    • pp.121-132
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    • 1994
  • This study was carried out to know the change of age-related hand function. 210 adults without neurosurgical and orthopedic disability from 15 to 90 years of age participation this study voluntarily. The results are as followings. 1. The hand function decreased according to age increasing. 2. The dominant and non-dominant hand function was decreased in ever-sixty age groups in the subtests of writing, card turning small common objects, simulated feeding, large light objects and large heavy objects greatly, but decreased between forty and fifty age groups in checkers greatly. 3. The dominant hand function was more excellent than non-dominant hand. 4. The dominant and non-dominant hand function was statistically significant between age groups(p<0.01). 5. The one-way ANOVA of subtests according to age increasing revealed significant statistically(p<0.01). 6. The correlation coefficients between subtests and age increasing revealed significant statistically in the dominant and non-dominant hand(p<0.01).

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Sexual Desire, Sexual Function, and Quality of Life in Married Women with Hypoactive Sexual Desire Disorder

  • Kim, HyeYoung
    • 보건교육건강증진학회지
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    • 제30권5호
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    • pp.163-175
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    • 2013
  • Objectives: This study was performed to identify the relationship among sexual desire, other domains of sexual function and quality of life (QOL) and to describe the effect of sexual desire on sexual function and QOL in married women with hypoactive sexual desire disorder (HSDD). Methods: A total of 397 women with HSDD participated in this study. Data were collected through self-reported questionnaire which were constructed to include general characteristics items, Female Sexual Function Index (FSFI), and QOL tool. Data were analyzed using SPSS/WIN20 for descriptive statistics, t-test, one-way ANOVA, Duncan, partial correlation coefficients, and Hierarchial multiple regression. Results: There were significant correlations with sexual desire and other domains of sexual function. And also, sexual desire had a positive correlations with the psychological status and total QOL. The sexual desire was statistically significant predictors for sexual function and QOL. Conclusions: Health professionals should direct efforts toward developing sexual health-related counseling or education programs for women suffering from sexual dysfunction with the goal of helping them to achieve satisfying sex lives and improved quality of life.

경쟁적 위험하에서의 신뢰성 분석 (Reliability Analysis under the Competing Risks)

  • 백재욱
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제16권1호
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    • pp.56-63
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    • 2016
  • Purpose: The purpose of this study is to point out that the Kaplan-Meier method is not valid to calculate the survival probability or failure probability (risk) in the presence of competing risks and to introduce more valid method of cumulative incidence function. Methods: Survival analysis methods have been widely used in biostatistics division. However the same methods have not been utilized in reliability division. Especially competing risks cases, where several causes of failure occur and the occurrence of one event precludes the occurrence of the other events, are scattered in reliability field. But they are not noticed in the realm of reliability expertism or they are analysed in the wrong way. Specifically Kaplan-Meier method which assumes that the censoring times and failure times are independent is used to calculate the probability of failure in the presence of competing risks, thereby overestimating the real probability of failure. Hence, cumulative incidence function is introduced and sample competing risks data are analysed using cumulative incidence function and some graphs. Finally comparison of cumulative incidence functions and regression type analysis are mentioned briefly. Results: Cumulative incidence function is used to calculate the survival probability or failure probability (risk) in the presence of competing risks and some useful graphs depicting the failure trend over the lifetime are introduced. Conclusion: This paper shows that Kaplan-Meier method is not appropriate for the evaluation of survival or failure over the course of lifetime. In stead, cumulative incidence function is shown to be useful. Some graphs using the cumulative incidence functions are also shown to be informative.

FES 치료 시 자극 주파수 차이가 퇴행성 슬관절염 환자의 대퇴근 기능에 미치는 영향 (Effects of Different Frequency on Muscle Function of the Thigh in Patients with Degenerative Knee Arthritis during the Functional Electrical Stimulation )

  • Woen-Sik, Chae;Jae-Hu, Jung
    • 한국운동역학회지
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    • 제32권4호
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    • pp.141-146
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    • 2022
  • Objective: The purpose of this study was to investigate the effects of different frequency on muscle function of the thigh in patients with degenerative knee arthritis during the functional electrical stimulation (FES). Method: For this study, 16 male participants over 65 who patients with degenerative knee arthritis were recruited as research participants. In this research, isokinetic muscular function, EMG, and joint position sensation were performed after FES treatment was applied for three conditions (FES 20, FES 50, and Without FES). For each dependent variable, one-way ANOVA with repeated measures was to determine whether there were significant differences among three different conditions (p<.05). When a significant difference was found, post hoc analyses were performed by using the contrast procedure. Results: When compared to FES 50 and without FES, FES 20 causes significant increase in isometric knee extension strength. No significant differences were found in EMG values across different EMS conditions. Conclusion: The present study examined isokinetic muscular function, EMG, and joint position sensation in order to investigate the effects of different frequency muscle function of knee extensors during the functional electrical stimulation. The results of this study showed that FES with 20 Hz frequency had positive effect on knee extensor. Based on the findings of the present study, FES with lower frequency may help the performer to focus on developing strength in knee extensor muscles.