• 대한수학회보
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• 제53권5호
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• pp.1447-1455
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• 2016

In this note, we mainly discuss the Gorenstein $Pr{\ddot{u}}fer$ domains. It is shown that a domain is a Gorenstein $Pr{\ddot{u}}fer$ domain if and only if every finitely generated ideal is Gorenstein projective. It is also shown that a domain is a PID (resp., Dedekind domain, $B{\acute{e}}zout$ domain) if and only if it is a Gorenstein $Pr{\ddot{u}}fer$ UFD (resp., Krull domain, GCD domain).

• 정보보호학회논문지
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• 제17권5호
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• pp.111-116
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• 2007

전자봉인 장치는 능동형 RFID장치로서, 화물 컨테이너의 문에 설치되어 컨테이너가 허가받지 않은 자에 의해 개봉되지 않았다는 것을 보증해 주는 장치이다. 전자 봉인장치는 RFID를 이용하므로 도청이나 위조를 막아야만 한다. 또한 보안 프로토콜을 사용하는 전자봉인 장치는 복제가 불가능해야 한다. 전자봉인의 복제 방지 기능이 제공되지 않는다면, 공격자는 컨테이너의 내용물을 바꾸어 넣은 다음에 복제된 전자봉인으로 재봉인 함으로서 전자봉인이 개봉되었었다는 사실을 숨길 수 있을 것이다. 본 논문에서는 도청과 위조를 방지함과 동시에, 봉인의 복제에 대한 저항성을 갖는 프로토콜을 제안하고자 한다.

• 대한인간공학회지
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• 제25권1호
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• pp.43-49
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• 2006

A laboratory study was conducted to evaluate if two different age groups(young vs. old) had differences in walking velocity and heel contact velocity and, furthermore, if these gait characteristics could adversely influence initial friction demand characteristics(i.e. RCOF) and the likelihood of slip-initiation. Twenty eight(14 younger and 14 older adults) participated in the study. While wearing a safety harness, all participants walked at their preferred gait speed for approximately 20 minutes on the linear walking track(1.5m× 20m) consisting of two floor-mounted forced plates. During subsequent 20 cameras, respectively. The results indicated that older adults walked slower(i.e., slower whole body center-of-mass velocity), exhibited lower heel contact velocity, and produced lower initial friction demand characteristics (i.e. RCOF) in comparison to younger adults. However, ANCOVA indicated that the diferences in heel contact velocity between the two age groups were due to the effects of walking velocity. The bivariate analysis further suggested that walking velocity was correlated to RCOF and heel contact velocity, while heel contact velocity was not found to be correlated to RCOF. In conclusion, could be a better indicator for predicting initial friction demand characteristics(i.e. RCOF) not hel contact velocity.

• 컴퓨터교육학회논문지
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• 제10권5호
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• pp.71-79
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• 2007

본 연구는 e-러닝 기반의 SPRT형 CAT모델에서 학습정보이력 요소(학습시간 및 모의테스트 점수)의 적용이 판정의 정확성에 어떠한 영향을 미치는지 알아보고자 보았다. 그 결과, e-러닝 기반의 SPRT 판정에 학습정보이력요소(학습시간과 모의테스트 점수) 변인을 적용하면 SPRT 판정의 정확성을 효율적으로 개선할 수 있음을 밝혀내었다. 특히 모의테스트 점수 변인은 거의 90%에 이르는 개선 효과를 보여주어 실제 e-러닝 평가 환경에서 곧바로 활용할 수 있는 변인으로 판명되었다. 따라서 학습정보이력요소를 평가영역의 SPRT와 접목시킨다면 학습자의 성적을 보다 정확하고 신속하게 판정할 수 있어, 궁극적으로 e-러닝 학습자의 개별화 촉진에 실제적으로 기여할 수 있을 것이다. 향후 다양한 학습정보이력요소를 반영한 알고리즘을 개발한다면 한 단계 높은 수준의 e-러닝 평가 프로그램을 제작할 수 있을 것이다.

• Corrosion Science and Technology
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• 제5권3호
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• pp.106-111
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• 2006

Painting has protected metallic stack but the paint films may be degraded and corrosion problem can be arisen. To protect the painted metal stack, cathodic protection can be applied. If cathodic protection is applied to bare metal, only small area may be protected. However, if cathodic protection is applied to painted metal surface, large area can be protected and the lifetime of paint films can be extended. High corrosion resistant alloys were corroded at a Flue Gas Desulfurization (FGD) facility of power plant within a short period and thus cathodic protection can be used to protect these metals. On the base of computer simulation, if cathodic protection is applied to bare metal in a FGD environment, it was estimated that applied current could almost be spent to protect area near the anode. However, if cathodic protection is applied to high resistant-coated metal, the much larger area from the anode could be effectively protected.

• 말소리와 음성과학
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• 제5권4호
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• pp.121-128
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• 2013

In Korean, wh-question and indefinite yes-no questions have the same morphemic and syntactic structure. In speech, however, these two types of questions are distinguished by a prosodic difference. In this study, we examined if Chinese Korean leaners can distinguish between these two types of questions in production and if they can correctly perceive the different meaning of a question based on the prosodic information. For this purpose, we analysed two types of interrogative sentences produced by 5 native speakers and 15 Chinese Korean language leaners. The results show that the 5 Korean native speakers produce two types of questions by a salient prosodic difference, i.e., difference of prosodic structure, different pitch range of wh-phrase and indefinite phrase, and different boundary tone. However, for the 15 Chinese speakers, the two types of questions were not distinguished by the same prosodic features but in the perception analysis they were able to distinguish between the two types of questions easily.

• 한국정보통신학회논문지
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• 제5권5호
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• pp.908-915
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• 2001

본 논문에서는 우선 반송파 주파수 오프셋이 OFDM/M-ary PSK 시스템에 미치는 성능 열 화를 분석하기 위해 오율식을 유도하였다. 그리고 Turbo 부호화 기법을 OFDM/M-ary PSK 시스템에 적용하여 성능 개선 정도를 평가하였다 최종적으로 Turbo Coded OFDM/M-ary PSK 시스템에서 요구하는 BER 성능을 만족시키기 위해 허용 가능한 최대 주파수 오프셋을 결정하였다. 성능 해석 결과 ary수가 커질수록 BER 성능이 열화됨을 알 수 있었고, 음성 서비스의 QoS (Quality of Service) 조건인 BER : $10^{-3}$을 만족시키려면 QPSK, 8PSK, 16PSK 변조 방식의 경우, 각각 약 7 dB, 9 dB, 17 dB의 $E_b/N_o$가 요구됨을 알 수 있었다 그리고 $E_b/N_o$/가 10 dB와 15 dB인 경우, $BER=10^{-3}$ 을 달성하기 위해서는 주파수 오프셋을 각각 0.05, 0075 이하로 유지해야 함을 알 수 있었다. 한편, OFDM/M-ary PSK시스템에 Turbo부호를 적용하면 ary수가 낮을수록 Turbo 부호의 성능 개선 효과가 크게 나타남을 알 수 있었다 그리고 16 ary이하의 PSK 변조 방식에 Turbo 부호화 기법을 적용한 경우, 데이터 서비스의 005 조건인 $BER=10^{-5}$을 만족시키려 면 약 8 dB 이하의 $E_b/N_o$가 요구됨을 알 수 있었다. 또한 Turbo 부호화 기법을 적용하면 매우 낮은 $E_b/N_o$ 값으로 음성 서비스를 충분히 지원할 수 있음을 알 수 있었고, 데이터 서비스는 주파수 오프셋 허용치에 관계없이 약 8 dB 정도의 $E_b/N_o$로 충분히 지원할 수 있음을 알 수 있었다.

• 대한수학회보
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• 제46권5호
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• pp.1013-1018
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• 2009

Let * be an e.a.b. star operation on an integrally closed domain D, and let $K\gamma$(D, *) be the Kronecker function ring of D. We show that if D is a P*MD, then the mapping $D_{\alpha}{\mapsto}K{\gamma}(D_{\alpha},\;{\upsilon})$ is a bijection from the set {$D_{\alpha}$} of *-linked overrings of D into the set of overrings of $K{\gamma}(D,\;{\upsilon})$. This is a generalization of [5, Proposition 32.19] that if D is a Pr$\ddot{u}$fer domain, then the mapping $D_{\alpha}{\mapsto}K_{\gamma}(D_{\alpha},\;b)$ is a one-to-one mapping from the set {$D_{\alpha}$} of overrings of D onto the set of overrings of $K_{\gamma}$(D, b).

• 호남수학학술지
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• 제45권3호
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• pp.397-409
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• 2023

Let R be an associative ring with identity and M be a left R-module. In this paper, we define modules that have the property (δ-CE) ((δ-CEE)), these are modules that have a δ-supplement (ample δ-supplements) in every cofinite extension which are generalized version of modules that have the properties (CE) and (CEE) introduced in [6] and so a generalization of Zöschinger's modules with the properties (E) and (EE) given in [23]. We investigate various properties of these modules along with examples. In particular we prove these: (1) a module M has the property (δ-CEE) if and only if every submodule of M has the property (δ-CE); (2) direct summands of a module that has the property (δ-CE) also have the property (δ-CE); (3) each factor module of a module that has the property (δ-CE) also has the property (δ-CE) under a special condition; (4) every module with composition series has the property (δ-CE); (5) over a δ-V -ring a module M has the property (δ-CE) if and only if M is cofinitely injective; (6) a ring R is δ-semiperfect if and only if every left R-module has the property (δ-CE).

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제5권2호
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• pp.175-178
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• 2005

In the present paper, we observe a relation between fuzzy norms and induced crisp norms on a linear space. We first prove that if $\rho_1,\;\rho_2$ are equivalent fuzzy norms on a linear space, then for every $\varepsilon\in(0.1)$, the induced crisp norms $P_\varepsilon^1,\;and\;P_\varepsilon^2$, respectively are equivalent. Since the converse does not hold, we prove it under some strict conditions. And consider the following theorem proved in [8]: Let $\rho$ be a lower semicontinuous fuzzy norm on a normed linear space X, and have the bounded support. Then $\rho$ is equivalent to the fuzzy norm $\chi_B$ where B is the closed unit ball of X. The lower semi-continuity of $\rho$ is an essential condition which guarantees the continuity of $P_\varepsilon$, where 0 < e < 1. As the last result, we prove that : if $\rho$ is a fuzzy norm on a finite dimensional vector space, then $\rho$ is equivalent to $\chi_B$ if and only if the support of $\rho$ is bounded.