• The KIPS Transactions:PartC
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• v.17C no.3
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• pp.233-242
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• 2010

In the recent years, power attacks were widely investigated, and so various countermeasures have been proposed. In the case of block ciphers, masking methods that blind the intermediate results in the algorithm computations(encryption, decryption) are well-known. In case of SEED block cipher, it uses 32 bit arithmetic addition and S-box operations as non-linear operations. Therefore the masking type conversion operations, which require some operating time and memory, are required to satisfy the masking method of all non-linear operations. In this paper, we propose a new masked S-boxes that can minimize the number of the masking type conversion operation. Moreover we construct just one masked S-box table and propose a new formula that can compute the other masked S-box's output by using this S-box table. Therefore the memory requirements for masked S-boxes are reduced to half of the existing masking method's one.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.11
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• pp.1363-1372
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• 1999

에이전트 기반 이동 컴퓨팅 환경에서 전자 상거래를 구현하기 위해 가장 필요로 하는 것은 안전한 지불 구조를 제공하는 것이다. 본 연구에서는 불확정 전송 기법 1,2 을 사용한 비대화형 엔티티 인증 기법과 Horster 기법 4,5 을 기반으로 메시지 복원 기능을 제공하는 공정 은닉 서명 기법을 제시한다. 또한 이를 직접 Brands가 제시한 오프-라인 전자 지불 시스템 3,6 에 접목한다. 인증 단계가 비대화형으로 수행되므로 이동 엔티티 인증에 효율적이고, 메시지 복원 기능을 갖고 공개 검증 기능을 제공하는 은닉 서명을 적용하기 때문에 카운터 방식을 사용한 스마트 카드 기반 전자 지불 시스템 6 에 효과적으로 적용할 수 있었다. 전자 화폐에 대해서 신뢰 센터에 의한 공정성 검토 기능을 추가로 제공하므로 전자 지불 시스템의 신뢰성을 향상시킬 수 있다.Abstract The primary requirements for realizing the electronic commerce in agent based mobile computing environments are to implement the compatible secure payment framework. In this paper, we propose both the non-interactive entity authentication scheme that is combined with oblivious transfer protocol 1,2 and the message recovery fair blind signature based on Horster scheme 4,5 . And these techniques are directly applied to the Brand's off-line electronic payment system 3,6 . As the authentication processes are done by non-interactive manner, we can also get efficiency for mobile entity authentication. Additionally, as the used signature scheme provides a message recovery function with publicly verifiable properties, it is efficiently applicable to a counter based off-line electronic payment scheme 6 based on the additional device like smart card. Therefore, we can enhance the reliability of proposed electronic payment system based on the publicly verifiable fairness in its electronic cash by a trusted judge.

• Journal of KIISE:Information Networking
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• v.30 no.2
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• pp.207-221
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• 2003

A hash chain is highly efficient, attractive structure to use in electronic cash. Previous systems using hash chain were, however, either credit-based vendor-specific cash or debit-based general-purpose cash which lacks efficiency due to double spending problem. In this paper, we propose a new divisible cash system using hash chain. This newly proposed cash is general-purpose, debit-based, anonymous, and offline. The efficiency of the system results from its capacity to pay variable amounts with no additional costs. A client always performs a single blind signature in the withdrawal phase, independent of the length of the chain. During payment, a client performs a single challenge-and-response or generates a single signature, independent of the amount paid. This system provides a new refund mechanism, which uses a refund ticket, that allows clients to refund the unspent part of the chain without revealing any connection to the spent part.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.9
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• pp.4045-4052
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• 2012

The aim of this single blind intervation study was to compare the analgesic effects of transcutaneous electrical nerve stimulation (TENS) and interferential currents (IFC) on cold-induced pain in healthy volunteers. Sixteen subjects completed six cycles of the cold-induced pain test. During each cycle pain threshold was recorded as the time from immersion of the subject is hand in cold water to the first sensation of pain and pain intensity and unpleasantness ratings were recorded using visual analogue scales. Subjects were randomly allocated to receive each 50 Hz-TENS, 50 Hz-IFC, 100 Hz-TENS and 100 Hz-IFC. Statistical analysis showed that four interventions elevated the cold pain threshold significantly and the difference between interventions was not simply significant. But, no significant differences were identified in pain intensity and unpleasantness ratings. We conclude that there were no differences in the analgesic effects of the four interventions under the present experimental conditions. But, 50 Hz-IFC has been shown to be more comfortable than other interventions.

• Journal of KIISE
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• v.42 no.6
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• pp.791-800
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• 2015

In this paper, we propose the contribution-level-based opportunistic flooding in a wireless multihop network which achieves outstanding transmission efficiency and reliability. While the potential of the the predetermined relay node to fail in its receipt of broadcast packets is due to the inherent instability in wireless networks, our proposed flooding actually increases network reliability by applying the concept of opportunistic routing, whereby relay-node selection is dependent on the transmission result. Additionally, depending on the contribution level for the entire network, the proposed technique enhances transmission efficiency through priority adjustment and the removal of needless relay nodes. We use the NS-3 simulator to compare the proposed scheme with dominant pruning. The analysis results show the improved performance in both cases: by 35% compared with blind flooding from the perspective of the transmission efficiency, and by 20~70% compared to dominant pruning from the perspective of the reliability.

• The Journal of Korean Medicine
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• v.27 no.4
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• pp.225-232
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• 2006

Objective : To test the hypotheses that individualized traditional Korean acupuncture improves pain and disability in patients with osteoarthritis of the knee and that benefits remain after stopping treatment more so than is the case for standardized minimal acupuncture. Design : Randomized single blind controlled trial with two intervention arms (individualized traditional Korean acupuncture, standardized minimal acupuncture) of six weeks' duration and three months follow-up. Setting : Acupuncture interventions were applied by two training doctors in the Department of Acupuncture and Moxibustion in a 1000-bed hospital. Assessment of the result was performed in a university-based laboratory. Participants : 50 patients with symptoms of knee osteoarthritis as diagnosed by an orthopedist. Intervention : Individualized traditional Korean acupuncture or standardized minimal acupuncture for six weeks. Main outcome measures: Primary outcome measure was pain as measured by the visual analogue scale. Secondary measures of pain and disability included the Western Ontario and McMaster Universities (WOMAC) index, Short Form-36 (SF-36), Lequesne Functional Index (LFI) score and Korean version of Health Assessment Questionnaire (KHAQ). Discussion : This paper presents detail on the rationale, design, methods and operational aspects of the trial.

• Clinical and Experimental Pediatrics
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• v.57 no.11
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• pp.479-483
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• 2014

Purpose: The efficacy of antibiotic therapy for acute sinusitis is controversial. This study aimed to compare the efficacies of amoxicillin with nasal irrigation and nasal irrigation alone for acute sinusitis in children. Methods: This randomized, double-blind, controlled study included 80 children aged 4-15 years with a clinical presentation of acute sinusitis. Patients were randomly assigned to receive either amoxicillin (80 mg/kg/day) in 3 divided doses orally for 14 days with saline nasal irrigation (for 5 days) and 0.25% phenylephrine (for 2 days) or the same treatment without amoxicillin. Clinical improvements in their initial symptoms were assessed on days 3, 14, 21, and 28. Results: On day 3, patients in the amoxicillin with nasal irrigation group showed significant clinical improvement (P=0.001), but there was no significant difference in the degree of improvement between the amoxicillin with nasal irrigation and nasal irrigation alone groups during follow-up (P>0.05). In addition, no significant differences were seen in age, sex, and degree of improvement between groups (P>0.05). Conclusion: High-dose amoxicillin with saline nasal irrigation relieved acute sinusitis symptoms faster and more often than saline nasal irrigation alone. However, antibiotic treatment for acute sinusitis confers only a small therapeutic benefit over nasal irrigation.

• Journal of the Korean Society of Costume
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• v.51 no.2
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• pp.93-103
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• 2001

This Study shows local characters, meaning, value and others (kind, function, material, shape, name) on Shroud through documents and fact-finding survey. In Shroud′s kind and function, Shroud of Kwangju Area is similar with one of Youngsan-river Area, while Sumjin-river Area and Coastal Area, each has its own character due to difference of Burial Culture. In Shroud′s Material, hemp cloth, white cotton cloth and calico, have been well-used in Kwangju and Youngsan-river Area, while silk has used in Sumjin-river and Coastal Area. Shroud′s color has followed Natural color. In Shroud′s shape, Male Jeoksam, Female Trousers, Um, Myokmok, Aksoo, Bib have their local characters. They are reformed in Kwangju Area and Youngsan-river Area. Jeoksam in Coastal Area, Female Trousers in Sumjin-river Area. Um in Coastal Area and Myokmok in Sumjin-river Area, have its unique character. In Shroud′s name, Shroud has widely been called "Dead Clothes", and called "Blind Clothes", "Munnyung Clothes" some areas. In Sumjin-river Area, Summer Jacket has been failed "Deungjigae", Dango called "Ddangjungwee". In Coastal Area, Myokmok and Aksoo have been called "Face Cover" and "Hands Cover", Shroud′s local characters have been caused by Next World, which has reflected local natural environment and cultural features. Next World is so abstract that it can not be expressed well, while Reality is clearly divided into dual spaces : Real World, Next World. Comprehension on Next World, helps harmonize recent values with Shroud meaning and prevents Shroud from standardization and transformation.

• Journal of Electrical Engineering and Technology
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• v.11 no.2
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• pp.529-536
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• 2016

In this paper we proposed an unsupervised algorithm to estimate the reverberation time (RT) directly from the reverberant speech signal. For estimation process we use maximum likelihood estimation (MLE) which is a very well-known and state of the art method for estimation in the field of signal processing. All existing RT estimation methods are based on the decay rate distribution. The decay rate can be obtained either from the energy envelop decay curve analysis of noise source when it is switch off or from decay curve of impulse response of an enclosure. The analysis of a pre-existing method of reverberation time estimation is the foundation of the proposed method. In one of the state of the art method, the reverberation decay is modeled as a Laplacian distribution. In this paper, the proposed method models the reverberation decay as a Gamma distribution along with the unification of an effective technique for spotting free decay in reverberant speech. Maximum likelihood estimation technique is then used to estimate the RT from the free decays. The method was motivated by our observation that the RT of a reverberant signal when falls in specific range, then the decay rate of the signal follows Gamma distribution. Experiments are carried out on different reverberant speech signal to measure the accuracy of the suggested method. The experimental results reveal that the proposed method performs better and the accuracy is high in comparison to the state of the art method.

• The Korean Journal of Nuclear Medicine
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• v.4 no.1
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• pp.37-42
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• 1970

In an endeavor to help understand some typical scan findings and portal hemodynamics in liver cirrhosis, several commonly occurring scan changes and esophageal varices as demonstrated by esophagram were correlated one another from quantitative and qualitative stand points. Clinical materials consisted of 34 patients with proven diagnosis of liver cirrhosis and esophageal varices. Liver scan was performed with colloidal 198-Au and the changes in the size and internal architecture of the liver, splenic uptake and splenomegaly were graded and scored by repeated double-blind readings. The variceal changes on esophagrams were also graded according to the classification of Shanks and Kerley following modification. Of 34 patients, 91% showed definite reduction in liver volume (shrinkage) constituting the most frequent scan change. The splenic uptake and splenomegaly were noted in 73.5 and 79.4%, respectively. The present study revealed no positive correlation between the graded scan findings including shrinkage of the liver, splenic uptake or splenomegaly and severity of variceal changes of the esophagus. Exceptionally, however, apparently paradoxical correlation was noted between the severity of mottlings and varices. Thus, in the majority (73.5%) of patients mottlings were either absent or mild. This interesting observation is in favor of the view held by Christie et al. who consider the mottlings to be not faithful expression of actual scarring of the cirrhotic liver. This also would indicate that variceal changes are to be the results of intrahepatic arteriovenous shunting of blood with hypervolemic load to the portal system rather than simple hypertension secondary to fibrosis and shrinkage.