• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제11권7호
• /
• pp.3720-3746
• /
• 2017

At present, numerous hospitals and medical institutes have implemented Telecare Medicine Information Systems (TMIS) with authentication protocols to enable secure, efficient electronic transactions for e-medicine. Numerous studies have investigated the use of authentication protocols to construct efficient, robust health care services, and recently, Liu et al. presented an authenticated key agreement mechanism for TMIS. They argued that their mechanism can prevent various types of attacks and preserve a secure environment. However, we discovered that Liu et al.'s mechanism presents some vulnerabilities. First, their mechanism uses an improper identification process for user biometrics; second, the mechanism is not guaranteed to protect against server spoofing attacks; third, there is no session key verification process in the authentication process. As such, we describe how the above-mentioned attacks operate and suggest an upgraded security mechanism for TMIS. We analyze the security and performance of our method to show that it improves security relative to comparable schemes and also operates in an efficient manner.

• 정보통신설비학회논문지
• /
• 제8권4호
• /
• pp.163-169
• /
• 2009

Recently, the concern of the FTA (Free Trade Agreement) have shifted to the promotion of the professional service's trade via the bilateral and reciprocal agreement of its professional laws. In the construction industry, this policy has intended to make the standardization of the construction manager's profession in the world. The purpose of this paper is 1) first to define the general model of professions in the U.S., UK and Japan, 2) then to declare the construction manager's model of the profession in them to apply the general model of professions, and 3) finally to analyze the identity of Korean construction managers and acquirement of its construction manager's law comparing with construction manager's model of the profession in the U.S., UK and Japan.

• Advanced Composite Materials
• /
• 제17권3호
• /
• pp.215-224
• /
• 2008

The present study aims to design a multilayer microstrip antenna with composite sandwich construction and investigate fatigue behavior of this multilayer SAS (surface antenna structure) that was asymmetric sandwich structure for the next generation of structural surface technology. This term, SAS, indicates that the structural surface becomes an antenna. Constituent materials were selected considering electrical properties, dielectric constant and tangent loss as well as mechanical properties. For the antenna performance, antenna elements inserted into structural layers were designed for satellite communication at a resonant frequency of 12.2 GHz. From electrical measurements, it was shown that antenna performances were in good agreement with design requirements. In cyclic 4-point bending, flexure behavior was investigated by static and fatigue test. Fatigue life curve of the SAS was obtained. The experimental results of bending fatigue were compared with single load level fatigue life prediction equations and in good agreement. The SAS concept is can be extended to give a useful guide for manufacturers of structural body panels as well as antenna designers.

• Korean Journal of Radiology
• /
• 제25권4호
• /
• pp.351-362
• /
• 2024

Objective: To measure inter-reader agreement and identify associated factors in interpreting complete response (CR) on magnetic resonance imaging (MRI) following chemoradiotherapy (CRT) for rectal cancer. Materials and Methods: This retrospective study involved 10 readers from seven hospitals with experience of 80-10210 cases, and 149 patients who underwent surgery after CRT for rectal cancer. Using MRI-based tumor regression grading (mrTRG) and methods employed in daily practice, the readers independently assessed mrTRG, CR on T2-weighted images (T2WI) denoted as mrCR_T2W, and CR on all images including diffusion-weighted images (DWI) denoted as mrCR_overall. The readers described their interpretation patterns and how they utilized DWI. Inter-reader agreement was measured using multi-rater kappa, and associated factors were analyzed using multivariable regression. Correlation between sensitivity and specificity of each reader was analyzed using Spearman coefficient. Results: The mrCR_T2W and mrCR_overall rates varied widely among the readers, ranging 18.8%-40.3% and 18.1%-34.9%, respectively. Nine readers used DWI as a supplement sequence, which modified interpretations on T2WI in 2.7% of cases (36/1341 [149 patients × 9 readers]) and mostly (33/36) changed mrCR_T2W to non-mrCR_overall. The kappa values for mrTRG, mrCR_T2W, and mrCR_overall were 0.56 (95% confidence interval: 0.49, 0.62), 0.55 (0.52, 0.57), and 0.54 (0.51, 0.57), respectively. No use of rectal gel, larger initial tumor size, and higher initial cT stage exhibited significant association with a higher interreader agreement for assessing mrCR_overall (P ≤ 0.042). Strong negative correlations were observed between the sensitivity and specificity of individual readers (coefficient, -0.718 to -0.963; P ≤ 0.019). Conclusion: Inter-reader agreement was moderate for assessing CR on post-CRT MRI. Readers' varying standards on MRI interpretation (i.e., threshold effect), along with the use of rectal gel, initial tumor size, and initial cT stage, were significant factors associated with inter-reader agreement.

• 한국초등과학교육학회지:초등과학교육
• /
• 제27권4호
• /
• pp.385-398
• /
• 2008

본 연구의 목적은 달 위상 변화 모형이 예비 초등 교사들의 개념 변화에 미치는 효과를 알아보는 것이다. 연구자는 연구 참여에 동의한 2명의 예비 초등 교사들과의 사전 면담 직후에 달 위상 변화 모형을 이용한 수업을 실시하였다. 한 달 뒤 사전면담 내용과 똑같은 내용은 '달 모양을 그림으로 그려 설명해 보세요.', '달 모양에 따른 태양, 지구, 달의 위치관계를 그림으로 그려 설명해 보세요.', '달의 위상 변화 원인을 무엇이라고 생각합니까?', '달이 한 쪽 면만 보이는 이유를 그림을 그려 설명해 보세요.'로 구성되었다. 연구 결과는 다음과 같다. 첫째, 달 위상 변화 모형을 이용한 수업은 태양, 지구, 달을 평면이 아닌 입체적으로 생각하도록 하여 달의 모양이 지구의 그림자 때문이라는 오개념을 바꾸는데 도움을 주었다. 둘째, 달 위상 변화 모형을 이용한 수업은 예비 초등 교사들로 하여금 달의 모양에 따른 태양, 지구, 달의 위치관계를 바르게 이해하는데 도움을 주었다. 셋째, 달 위상 변화 모형을 이용한 수업은 예비 초등 교사들에게 달 위상 변화 원인에 대한 과학적 개념을 형성하게 하는데 도움을 주었다. 넷째, 달이 한쪽 면만 보이는 이유에 대한 학습은 달 위상 변화 모형을 이용하여 설명하기에는 부적절한 것으로 나타났다. 이상의 연구 결과를 토대로 연구자는 본 모형이 가진 한계점을 인식하고 좌표계에 대한 명확한 구분과 이해를 바탕으로 달 위상 변화 모형을 수업에 이용할 경우, 학습자의 공간지각력 향상 및 달의 위상 변화를 이해하는데 도움을 줄 수 있다는 것을 제안하였다.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2008년도 추계학술대회 논문집
• /
• pp.367-369
• /
• 2008

A theoretical model of equivalent drawbead for sheet metal forming analysis is experimentally verified in this paper. After the theoretical drawbead models improved a material description for the accurate calculation of drawbead forces are briefly introduced, they are verified by showing the good agreement of their drawbead forces with experimental measurements. Furthermore, the excellence of theoretical models is demonstrated by the comparison with those of commercial codes.

• Journal of Electrical Engineering and Technology
• /
• 제4권3호
• /
• pp.401-404
• /
• 2009

A simple analytical expression for a current gain of IGBT is derived in terms of the device parameters as well as a gate length dependent parameter, which allows for the determination of the current components of the device as a function of its gate length. The analytical results are compared with those from simulation results. A good agreement is found.

• 대한화학회지
• /
• 제11권1호
• /
• pp.22-27
• /
• 1967

천이상태 이론을 액체 산소에 적용하여 열역학적량을 구하였다. 그 결과는 실험치와 근사하게 일치함.

• 한국원자력학회:학술대회논문집
• /
• 한국원자력학회 1997년도 춘계학술발표회논문집(2)
• /
• pp.407-412
• /
• 1997

The predictive results between a dynamic food-chain model (DYNACON) and an equilibrium model (NRC model) were compared to show the physical validity of DYNACON. Although the mathematical formulations and transport processes of radionuclides in the environment are different between two models, the comparative study shows good agreement for deposition events that occur during the growing season of plants.

• 천문학회지
• /
• 제36권spc1호
• /
• pp.1-5
• /
• 2003

In an early paper Skumanich suggested the existence of a scaling law relating the mean sunspot magnetic field with the square-root of the photospheric pressure. This was derived from an analysis of a variety of theoretical spot models including those by Yun (1968). These were based on the Schliiter-Temesvary (S- T) similarity assumption. To answer criticisms that such modeling may have unphysical (non-axial maxima) solutions, the S-T model was revisited, Moon et al. (1998), with an improved vector potential function. We consider here the consequences of this work for the scaling relation. We show that by dimensionalizing the lateral force balance equation for the S- T model one finds that a single parameter enters as a characteristic value of the solution. This parameter yields Skumanich's scaling directly. Using an observed universal flux-radius relation for dark solar magnetic features (spots and pores) for comparison, we find good to fair agreement with Yun's characteristic value, however the Moon et al. values deviate significantly.