• The Journal of Korean Institute of Communications and Information Sciences
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• 제25권12B호
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• pp.2094-2108
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• 2000

오류를 수반하는 통신망을 통한 멀티미디어 데이터의 응용은 최근 그 수요가 급증하고 있다. 하지만 그 구현은 많은 문제점들을 야기하는데, 전송된 비디오 데이터에 발생한 오류를 처리하는 문제가 그 중 하나이다. 이는 압축된 비트열에 발생한 오류가 영상의 시-공간 방향으로 심각한 전파 현상을 수반하기 때문이다. 이러한 심각한 오류 전파를 완화하기 위해 본 논문에서는 EREC라 알려진 오류 제한 기법을 적용하고, 적용된 EREC의 오류 전파 특성을 분석하였다. 이를 통해, 압축 부호화된 하나의 기본 블록 (매크로 블록)이 복호시 오류가 생길 확률을 추정하였으며, 추정된 확률의 근사를 통해 양 끝단(전송단과 수신단)에서의 비디오 화질 열화를 예측하였다. 추정 확률의 근사는 매 기본 블록에서 발생된 비트수에 대한 그 기본 블록이 복호시 오류가 생길 확률을 간단한 1차식을 통한 선형 회귀법으로 모델링 되었으며, 따라서 간단한 방법을 통해 양 끝단의 화질 열화를 효과적으로 예측할 수 있었다. 부호화된 비트열이 전송 오류에 보다 강인하게 되도록 하기 위해, 본 논문에서 개발된 화질 열화 모델을 양자화기 선택에 적용함으로써, 새로운 최적 양자화 기법을 제시하였다. 본 논문에서 제안된 최적 양자화 기법은, 기존의 양자기 최적화 기법들과는 달리, 복호단에서의 복원 영상 화질이 주어진 비트율에서 최적이 되도록 양자화를 수행한다. H.263 비디오 압축 규격에 적용한 제안 양자화 기법의 실험 결과를 통해, 제안 기법이 매우 적은 계산상의 부하를 비용으로 객관적 화질은 물론 주관적 화질까지 크게 개선할 수 있음을 확인할 수 있었다.내었다.Lc. lacti ssp. lactis의 젖산과 초산의 생성량은 각각 0.089, 0.003과 0.189, 0.003M이었다. 따라서 corn steep liquor는 L. fermentum와 Lc. lactis ssp, lactis 의 생장을 위해 질소 또는 탄소 공급원으로서 배지에 첨가 될 수 있는 우수한 농업 부산물로 판단되었다.징하며 WLWQ에 적용되는 몇 가지 제약을 관찰하고 이를 일반적인 언어원리로 설명한다. 첫째, XP는 주어로만 해석되는데 그 이유는 XP가 목적어 혹은 부가어 등 다른 기능을 할 경우 생략 부위가 생략의 복원 가능선 원리 (the deletion-up-to recoverability principle)를 위배하기 때문이다. 둘째, WLWQ가 내용 의문문으로만 해석되는데 그 이유는 양의 공리(the maxim of quantity: Grice 1975) 때문이다. 평서문으로 해석될 경우 WP에 들어갈 부분이 XP의 자질의 부분집합에 불과하므로 명제가 아무런 정보제공을 하지 못한다. 반면 의문문 자체는 정보제공을 추구하지 않으므로 앞에서 언급한 양의 공리로부터 자유롭다. 셋째, WLWQ의 XP는 주제어 표지 ‘는/-은’을 취하나 주어표지 ‘가/-이’는 취하지 못한다(XP-는/-은 vs. XP-가/-이). 이는 IP내부 에 비공범주의 존재 여부에 따라 C의 음운형태(PF)가 시성이 정해진다는 가설로 설명하고자 했다. WLWQ에 대한 우리의 논의가 옳다면, 본 논문은 다음과 같은 이론적 함의를 기닌다. 첫째, WLWQ의 존재는 생략에 대한 두 이론 즉 LF 복사 이론과 PF 삭제 이론

• Korea Journal of Hospital Management
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• 제7권3호
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• pp.1-24
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• 2002

The purpose of this study was to find the factors affecting the bum out syndrome and its degree in terms of personal, organizational and clients characteristics, and then to find the ways to reduce or eliminate those factors. The 228 doctors and the nurses who worked at the emergency departments in 6 general hospitals with more than 700 beds in Seoul were surveyed from April 15, 2002 for 15 days. A structured self-recording questionnaire was used; the t-test and ANOVA was used to analyse the median difference between the occupation, and multiple regression was employed to find the factors affecting the bum-out syndrome. The summary of this research analysis is as follows : First, of several variables, the highest frequency of the burn-out was the emotional burn-out followed by lack in personal touch toward the patients, decrease in sense of personal achievement. These results indicate that the doctors and nurses in emergency departments experience higher degree of burn-out than the social workers and the nurses who work at other departments in heath care environment as other studies revealed. Second, the analysis of the total burn-out factors showed the lower self respect, younger age, heavier work load, higher dissatisfaction rate toward remuneration and not-so-smooth relationship with the patients and their relatives the higher burn out rate. These variables explained 54% of the total variables. Third, the nurses experienced more burn-out syndrome than the doctors. The degree of self-respect, work pattern, relationship with the clients, age and remuneration were the causes of the burn-out. The doctors recorded lack in personal touch toward the patients more, while the nurses more to emotional exhaustion. The limitations of this research are the subjective answers of the respondents to certain questions and differences in sample numbers of each hospital in which some reservation can be exercised in explaining statistical significance of the data, and generalizing the conclusion. Despite of its limitation, this research has its own merit as an unpreceded research in this field, and provision of the basic materials to prevent and find causes of the burn-out syndrome among the doctors and nurses in the emergency departments.

• Korea Journal of Hospital Management
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• 제23권3호
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• pp.28-38
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• 2018

Purpose: To evaluate the medical expenditures for prostate cancer patients, including out-of-pocket costs, and compared the costs between androgen deprivation therapy and radical prostatectomy treatment. Methodology: This study combined clinical data from 357 prostate cancer patients from the Smart Prostate Cancer Database and the medical expenditure data from the claims and cost databases. We used the independent two-sample t-tests to compare androgen deprivation therapy and radical prostatectomy. Multivariable logistic regression analysis was conducted to identify determining factors for androgen deprivation therapy and radical prostatectomy treatments. Findings: The medical costs of androgen deprivation therapy treatment were much lower than radical prostatectomy treatment at the one year and remained lower until the fourth-year. However, after four years, the accumulated medical expenditures of androgen deprivation therapy become significantly higher than radical prostatectomy treatment. Patients with a higher cancer stage and older age had higher chances of being treated using androgen deprivation therapy treatment than radical prostatectomy treatment. Practical Implications: Our results show that early detection of cancer reduces the treatment cost for both patients and insurance payers. It also demonstrates that cost comparisons should be conducted over long periods of time in order to most accurately assess the costs.

• Journal of Hydrogen and New Energy
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• 제16권2호
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• pp.122-129
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• 2005

The characteristics of hydrogen storage have been investigated in the Ti-Cr-Mo and Ti-Cr-V ternary alloys with bcc structure. The alloys were melted by arc furnace and remelted 4-5 times for homogeneity. The lattice parameters, microstructures and phases of the alloys were examined by SEM, EDX and XRD, and the Pressure-Composition isotherms of the alloys were measured. From these data the relationship of the maximum and effective hydrogen storage capacities vs. chemical composition, lattice parameter and the radius of tetrahedral site were analyzed and discussed. The results showed that all of these alloy, in the range of the this study, had mainly bcc solid solutions with small amount of Ti segregation due to a lower melting point of Ti compared with other elements. Lattice parameters of the alloys were very near to the atomic average values of lattice parameters of the constituent elements. It was also found that maximum hydrogen storage capacities of the Ti-Cr-Mo alloys increased with increasing Ti content and the radius of tetrahedral site but the effective hydrogen storage capacities decreased after showing the maximum. The hydrogen storage capacities of the Ti-Cr-V alloys were almost same even though the V contens were quite different from alloy to alloy and this could be attributed to the almost same Ti/Cr ratio of the alloys. The maximum effective hydrogen storage capacity of the Ti-Cr-Mo alloys was revealed at Ti content of about 40${\sim}$50 at% and radius of tetrahedral site of 0.43${\sim}$0.45 nm. The Ti-Cr-V alloys showed the hydrogen storage capacities of 3.0 wt% and effective hydrogen storage capacities of 1.5 wt%.

• Journal of Families and Better Life
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• 제28권5호
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• pp.25-38
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• 2010

The purpose of this study was to investigate the trend changes of the health characteristics and the elements of Han-Ok appeared in the articles of the daily newspaper, and to provide basic information for applying to the healthy housing for the public living in modern society and furthermore the various facilities for healing. For the study, the relevant articles of 4 daily newspapers published from 1st of January in 1960 to 28th of February in 2010 were collected and analyzed. The results of the study were as follows: First, the articles about the health characteristics and the elements of Han-Ok have rapidly grown since the year of 2000. Especially, the residents' interviews, case reports and actual living condition of Han-Ok recently tend to increase. Second, the health characteristics of Han-Ok in the recent articles were focused more on the mental and social health than on the physical health. The physical health had the characteristics of the block of hazard environments, the offer of good quality environments, and the enhancements of residents' health. The mental health consisted of the psychological comfort, the sensory satisfaction and the emotional growth. There have been improvements of family relationships and the interactions with neighbors in the characteristics of social health since 2000. Third, the health elements of Han-Ok in terms of architecture and interior design were the structure, space, material, doors & windows, furniture & props, nature, and villages. The material elements were more stressed before 2000, but the spaces and the nature elements were highly focused after 2000 and the structure elements were steadily high regardless of years. Fourth, of the health elements, the structure and the material had the high effects on the physical health characteristics, on the other hand the spaces and the nature influenced more on the mental health. On-dol, Ma-dang, Dae-cheong, Ma-ru, soil, wood, Changhoji, natural environments, and doors & windows were the detail health elements which had high effects on the health characteristics of Han-Ok. For the future study, the experience based in-depth studies of the residents living in Han-Ok are suggested to grasp the actual effects of Han-Ok on the health. The professional consultations are also needed for the extracts of the health characteristics of Han-Ok and the functional elements which can be applied to the modern buildings.

• Convergence Security Journal
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• 제6권3호
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• pp.1-12
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• 2006

Malicious codes have been widely documented and detected in information security breach occurrences of Microsoft Windows platform. Legacy information security systems are particularly vulnerable to breaches, due to Window kernel-based malicious codes, that penetrate existing protection and remain undetected. To date there has not been enough quality study into and information sharing about Windows kernel and inner code mechanisms, and this is the core reason for the success of these codes into entering systems and remaining undetected. This paper focus on classification and formalization of type target and mechanism of various Windows kernel-based attacks, and will present suggestions for effective response methodologies in the categories of, "Kernel memory protection", "Process & driver protection" and "File system & registry protection". An effective Windows kernel protection system will be presented through the collection and analysis of Windows kernel and inside mechanisms, and through suggestions for the implementation methodologies of unreleased and new Windows kernel protection skill. Results presented in this paper will explain that the suggested system be highly effective and has more accurate for intrusion detection ratios, then the current legacy security systems (i.e., virus vaccines and Windows IPS, etc) intrusion detection ratios. So, It is expected that the suggested system provides a good solution to prevent IT infrastructure from complicated and intelligent Windows kernel attacks.

• KSBB Journal
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• 제24권1호
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• pp.75-79
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• 2009

The effect of inorganic, organic nitrogen sources and amino acids on the coenzyme $Q_{10}$ production and coenzyme $Q_{10}$ component ratio was investigated. Among the nine organic nitrogen sources, CSP showed a remarkable enhancing effect on the production of coenzyme $Q_{10}$. But this enhancement was not observed in medium containing Bacto peptone, tryptone, casamino acid and soybean meal. These differences on the production of coenzyme $Q_{10}$ may be due to differences in kinds and amounts of component amino acids and peptides in the various organic nitrogen sources tested. In the addition of inorganic nitrogens, only $(NH_4)_2SO_4$ increase the coenzyme $Q_{10}$ production by 2.0 times compare to the control group. The addition of L-tyrosine to the medium containing Bacto tryptone, was also determined to be crucial for the coenzyme $Q_{10}$ production. But phenylalanin and tryptophan, other aromatic amino acids, had no stimulatory effect on the coenzyme $Q_{10}$ production. These results show that the production and components ratio of coenzyme $Q_{10}$ was greatly affected by the kinds and the concentration of inorganic, organic nitrogen sources as well as amino acids.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제33권3C호
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• pp.247-254
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• 2008

H.264 provides a good coding efficiency compared with existing video coding standards, H.263, MPEG-4, based on the use of multiple reference frame for variable block size motion estimation, quarter-pixel motion estimation and compensation, $4{\times}4$ integer DCT, rate-distortion optimization, and etc. However, many modules used to increase its performance also require H.264 to have increased complexity so that fast algorithms are to be implemented as practical approach. In this paper, among many approaches, fast mode decision algorithm by skipping variable block size motion estimation and spatial-predictive coding, which occupies most encoder complexity, is proposed. This approach takes advantages of temporal and spatial properties of fast mode selection techniques. Experimental results demonstrate that the proposed approach can save encoding time up to 65% compared with the H.264 standard while maintaining the visual perspectives.

• Journal of the Korean Ceramic Society
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• 제34권2호
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• pp.216-224
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• 1997

Porous silica ceramics were prepared(with HCI catalyst) using H2O/TEOS molar ratios of 2.6~59.0, with the EtOH/TEOS ratio fixed. After preparing 9 kinds of sol, the followings were investigated; measurement of the gelation time, thermal analyses by TG/DTA, property analyses of the intermediates by FT-IR and X-ray diffractometry with dried samples, analyses of SiO2 polymer by FT-IR, the investigation of specific sur-face area and pore size distribution by N2-adsorption isotherm, and structural change of SiO2 polymer and pore morphology by TEM observation, with samples heat-treated to 50$0^{\circ}C$. In the concentrations of in-vestigated compositions and catalyst, gelation time showed a minimum at ca. 11 moles of water per one mole of TEOS, the highest degree of polymerization at ca. 8-18 moles, and the largest specific surface area at ca. 11 moles, which means that the polymerization proceeded fastest at ca. 11 moles of water. In con-clusion, the more water used, the faster the polymerization reaction up to ca. 11 moles, but more than ca. 11 moles of water caused retardation of gelation and resultant reduction of specific surface area.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.306-306
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• 2010

21 세기는 언제, 어디에서, 누구나가 정보를 자유롭게 염가에 이용할 수 있는 유비쿼터스 정보사회가 될 것으로 예상하고 있다. 이러한 유비쿼터스 사회가 실현되기 위해서는 필연적으로 대두되고 있는 과제가 에너지 공급원의 문제이다. 휴대용 전자제품이나 소형 에너지 공급원으로 지금까지 주로 전지가 사용되어 왔지만 이것들은 교환 및 충전이 불가피하다. 이러한 불편함을 개선하기위해 교환과 충전이 불필요하거나 아주 장시간동안 공급해주는 형태의 에너지 공급원의 필요성이 대두되고 있다. 이러한 에너지 공급원으로 최근에 많은 연구가 되고 있는 것이 주위의 환경으로부터 버려지는 에너지를 수확(harvesting)하여 전력으로 변환하는 에너지 하베스팅 (energy harvesting)기술이 연구 개발되고 있다. 에너지 하베스팅 응용을 위해서 사용되어지는 압전 세라믹스는 전압출력계수 ($g_{33}$)가 커야하는데 이것은 압전상수 ($d_{33}$)와 유전상수 (${\varepsilon}_{\tau}$)의 값에 영향을 받는 것으로 알려져있다. 그 중에서 우수한 전기적 특성 때문에 PZT를 기반으로 하는 압전 세라믹스가 사용되어져왔다. 그러나 Pb의 높은 유독성과 Pb를 포함하는 제품들의 처분문제들로 인해 제조에 관한 많은 문제점들을 지니고있다. 그리하여, Pb를 포함하지 않는 Pb-free계에 관한 연구가 전세계적으로 활발히 진행되고 있다. 다양한 Pb-free계 후보자들 가운데 $K_{0.5}Na_{0.5}NbO_3$ (KNN)는 높은 큐리온도와 좋은 강유전 특성 및 압전특성 때문에 PZT를 대체할 가장 장래성있는 대안들 중의 하나로 고려되고 있다. 그러나 고온에서 알칼라인 원소들의 높은 휘발성 때문에 보통의 소결공정으로는 소결이 잘되고 치밀한 세라믹스를 얻기가 어렵다. 많은 연구에서 KNN 세라믹스의 소결성을 개선하기 위하여 강유전 또는 반강유전체인 $SrTiP_3$와 $LiTaO_3$를 고용체 형성에 포함시키고 또한 $K_4CuNb_8O_{23}$, $MnO_2$, CuO등과 같은 소결조제를 첨가하여 압전 특성과 소결성을 개선시켰다. 따라서 본 연구에서는 비화학양론적 (1-X)[$[(K_{0.5}Na_{0.5}]_{0.97}(Nb_{0.96}Sb_{0.04})O_3]$ + 0.008CuO + 0.2wt% $Ag_2O$ + X $CeMnO_3$의 조성을 사용하여 A사이트와 B 사이트에 각각 Ce이온과 Mn 이온의 치환량을 변화하여 그에 따른 유전 및 압전특성을 조사하였다.