• 정보보호학회논문지
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• 제15권3호
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• pp.77-89
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• 2005

Pairing을 이용한 신원기반의 공개키 암호시스템에 대한 연구가 활발히 진행되면서 신원기반의 다양한 키 합의 프로토콜이 제안되었으나, 대부분의 기법들이 키 합의 프로토콜에서 요구되는 보안 요구사항을 만족하지 않는 것으로 분석되었다. 그리고 최근 Liu 등과 Kim 등은 한 번의 프로토콜의 수행을 통해 복수개의 키를 설정할 수 있는 키 합의 프로토콜을 제안하였다. 본 논문에서는 Liu 등의 기법을 개선한 신원기반의 3자간 복수개의 키 합의 프로토콜을 제안한다. Liu 등의 기법과 유사하게 키 교환 메시지에 서명을 추가하지만 Liu 등의 기법보다 효율적인 프로토콜의 수행이 가능하다. 그리고 제안 프로토콜은 서로 다른 여러 키 발급센터(Private key generator, PKG)들이 관여하는 환경에서도 프로토콜의 수행이 가능하며, 프로토콜에 참여하는 각 개체들이 자신의 소속에 따라 별개의 키 발급센터로부터 발행된 개인키를 사용할 수 있으므로 보다 실용적이며 효율적으로 적용될 수 있다.

• Clinical and Experimental Reproductive Medicine
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• 제18권2호
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• pp.201-208
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• 1991

Recently the application of gonadotropin-releasing hormone (GnRH) agonist to superovulation in previous poor responders has resulted in the improved outcomes after in vitro fertilization (IVF) outcome. However, poor responders with poor estradiol $(E_2)$ rise or single dominant follicle are a particularly challenging group. Recent reports have also shown that patients with higher basal serum follicle stimulating hormone (FSH) level, result in poorer ovarian response and lower pregnancy rate. Analysis of the differences of superovulation outcomes according to the different protocols of GnRH agonist, long (L, n = 18) and short (S, n = 16) protocols, in patients with high basal FSH levels (>20mIU/ml) were undertaken at Seoul National University Hospital from June to October 1990. The administration of GnRH agonist was begun on day 21 of the cycle in long protocol, and on day 2 in short protocol. Ages of patients and husbands, basal FSH and luteinizing hormone (LH) levels and FSH/LH ratio did not differ significantly. Types and causes of infertility were evenly distributed. Whereas the duration of stimulation and the amounts of gonadotropins administered were significantly reduced in short protocol, the numbers of oocytes retrieved and cleaved, the cleavage rate and the number of embryos transferred were higher in long protocol without statistical signifieance. The pregnancy rate per ET was 16.7% (2/12) in short protocol, and 17.6% (3/17) in long protocol. These data suggest that both protocols result in the similar superovulation outcomes in patients with higher basal serum FSH levels.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.7-10
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• 2005

Ad hoc MAC protocols using directional antennas can be used to improve the network capacity. Directional antennas have a Deafness problem and decrease throughput of the network caused by increasing backoff duration. Dual channel protocols have been proposed to mitigate the Deafness and hidden node problems. In this paper, we propose a dual channel MAC protocol using a directional antenna to mitigate the Deafness problem and increase the network capacity. The performance of the proposed Ad hoc MAC protocol is confirmed by computer simulations using Qualnet ver. 3.8 simulator.

• 대한수학회보
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• 제50권6호
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• pp.1799-1816
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• 2013

Privacy preserving multiset union (PPMU) protocol allows a set of parties, each with a multiset, to collaboratively compute a multiset union secretly, meaning that any information other than union is not revealed. We propose efficient PPMU protocols, using multiplicative homomorphic cryptosystem. The novelty of our protocol is to directly encrypt a polynomial by representing it by an element of an extension field. The resulting protocols consist of constant rounds and improve communication cost. We also prove the security of our protocol against malicious adversaries, in the random oracle model.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.57-58
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• 2006

Ad hoc MAC protocols using directional antennas can be used to improve the network capacity by improving spatial reuse. But, the directional MAC protocols have the problem of deafness and have a poor throughput performance. The dual-channel DMAC protocol has been proposed to mitigate deafness and improve spatial reuse. In this paper, we propose a dual-channel DMAC protocol using the omnidirectional antenna for an out-of-band tone and directional antennas for control/data channels. In the proposed MAC protocol, an omnidirectional out-of-band tone mitigates deafness and directional antennas used in control/data channels improve spatial reuse and reduce interference packets. The throughput performance of the proposed MAC protocol is confirmed by computer simulations using Qualnet ver. 3.8 simulator.

• 펄프종이기술
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• 제47권5호
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• pp.33-42
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• 2015

Pitches contained in thermomechanical pulp negatively influence paper qaulity and pulp and papermaking process. Without controlling TMP pitches suitably, it is hard to make a certain quality of paper. In order to control pitches in TMP, they must be quantitatively recognized by proper tools. One of the most widely used way to detecting TMP pitches is a staining method using a hydrophobic dye such as Sudan IV. Sudan IV could be used with three different protocols including different application of its dissolution, washing, dyeing time, etc. The dyeing protocols were classified into three categories including Stain I, Stain II, and Stain III. In dyeing time, Stain I required more than 24 hours to dye pitches. On the other hand, Stain III could stain TMP pitches with the most brief way. The images of red-stained pitches could be captured by a stereomicroscope with ${\times}35$ and ${\times}45$ magnifications, and then quantitatively analysed measuring their numbers and areas by Carl Zeiss AxioVision (ver. 4.8.2) program. Among three protocols, both Stain I and Stain III were the most ideal methods to detect TMP pitches because they detected more pitches and bigger pitch areas compared to Stain II against the same specimen. In particular, it was recognized that Stain III could be used as the most useful tool to detect TMP pitches accurately within several minutes.

• 한국응급구조학회지
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• 제14권2호
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• pp.57-69
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• 2010

Purpose : The National Registry Exam had some problems on validity of EMT evaluation and verification. The aim of this study was to propose a New EMT National Registry Exam. Methods : Conducted using the Delphi Method(lst meeting March 29 in 2008, 2nd meeting May 31 in 2008, 3rd meeting September 20 in 2008, 4th meeting January 16 in 2009) from questionnaire data(391 from Paramedic, 317 from Basic EMT) collected between June 16-30(lst questionnaire) and October 16-30(2nd questionnaire) in 2008 and a public hearing on February 5 in 2009. Results: The subjects proposed at the request of the National Health Personnel Licensing Examination Board were Introduction, Medical+Trauma Emergencies(Paramedic & Basic) for written examination and scenarios+protocols(Paramedic), protocols(Basic) for practical examination. Conclusion : To be able to response patients' problems in various emergencies, this integrated examination was selected and proposed.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1998년도 추계학술대회
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• pp.271-272
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• 1998

Contrast-enhanced CT has an important role in the assessment of liver lesions. However, the optimal protocol to get most effective result is not clear. The main principle for deciding injection protocol is to optimize lesion detectability by rapid scanning when lesion-to-liver contrast is maximum. For this purpose, we developed a physiological model of contrast medium enhancement based on the compartment modeling and pharmacokinetics. Blood supply to liver was modeled in two paths. This dual supply character distinguishes the CT enhancement of liver from that of the other organs. The first path is by hepatic artery and the second is by portal vein. It is assumed that only hepatic artery can supply blood to hepatocellular carcinoma (HCC) compartment. It is known that this causes the difference of contrast enhancement between normal liver tissue and hepatic tumor. By solving differential equations for each compartment simultaneously using computer program Matlab, CT contrast-enhancement curves were simulated. Simulated enhancement curves for aortic, hepatic, portal vein, and HCC compartments were compared with mean enhancement curves from 24 patients exposed to the same protocols as simulation. These enhancement curves were in a good agreement. Furthermore, we simulated lesion-to-liver curves for various injection protocols, and analyzed the effects. These may help to optimize the scanning protocols for good diagnosis.

• 한국임상수의학회지
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• 제37권5호
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• pp.235-241
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• 2020

We aimed to determine the effect of timed artificial insemination (TAI) protocols on the pregnancy rate per insemination and pregnancy loss compared with AI performed at detected estrus in dairy cows and Korean Hanwoo cattle under heat stress. In dairy cattle, 1,250 sets of data that underwent AI during heat stress (temperature-humidity index ≥ 72) were categorized according to their TAI protocols or as controls: 1) PGF_2α-36 h-estradiol benzoate (EB)-36 h-TAI (PG-EB group, n = 113); 2) GnRH-7 days-PGF_2α-56 h-GnRH-16 h-TAI (Ovsynch group, n = 455); or 3) GnRH-6 days-Ovsynch (G6G group, n = 136). The remaining cows underwent AI at detected estrus (AIDE group, n = 546). The probability of pregnancy per AI 45 days after AI was higher (P < 0.01) in the PG-EB (odds ratio [OR]: 1.68), Ovsynch (OR: 1.48), and G6G (OR: 1.79) groups than in the AIDE group. However, the prevalence of pregnancy loss between 30 and 45 days after AI did not differ among the groups. In Hanwoo cattle, 617 sets of data inseminated artificially under heat stress were categorized into AIDE (n = 281), PG-EB (n = 194), and combined Ovsynch or G6G (n = 142) groups. The probability of pregnancy per AI 45 days after AI and the prevalence of pregnancy loss between 30 and 45 days after AI did not differ among the groups. Thus, implementation of a TAI protocol (PG-EB, Ovsynch, or G6G) in dairy cows under heat stress improves the pregnancy rate per AI versus AIDE, whereas there is no beneficial effect of TAI on the pregnancy rate of Hanwoo cattle under heat stress.

• 정보보호학회논문지
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• 제18권3호
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• pp.109-120
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• 2008

VoIP 서비스는 인터넷을 이용하기 때문에 기존 침해 및 공격이 쉽게 이루어질 수 있는 문제점을 가지고 있다. 특히 VoIP를 통해 제공되는 서비스는 사용자의 프라이버시와 관련된 정보를 다루기 때문에 사용자 인증, 시그널링 메시지나 미디어 스트림의 암호화/무결성 등의 보안은 필수적이고 VoIP 전화기에 보안을 위한 프로토콜의 구현은 한정된 연산 및 저장자원, 성능을 고려한 구현이 요구된다. 이에 따라 본 논문에서는 시그널링과 미디어를 위한 보안 프로토콜간의 성능평가를 통해 이러한 고려사항을 만족하는 프로토콜을 확인하고자 한다. 시그널링 보안으로 TLS와 DTLS, 미디어 보안으로 SRTP와 DTLS, 키 교환 프로토콜로 MIKEY, ZRTP, DTLS를 구현하고 SIP 프록시 및 UA(User Agent)에 적용하여 접속 품질과 음성 품질에 관한 프로토콜간의 비교를 수행하였다. 성능 평가 결과 보안 프로토콜 적용으로 인한 음성 품질의 저하가 발생하지 않았지만 접속 품질의 경우 DTLS를 기반으로 하는 보안 프로토콜이 비교적 우수한 성능으로 측정되었고, DTLS는 UDP를 기반으로 시그널링과 미디어 경로에 모두 적용이 가능하기 때문에 VoIP 전화기의 한정된 성능과 자원 문제를 해결할 수 있는 것으로 나타났다.