• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 추계학술발표회논문집(1)
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• pp.15-20
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• 1996

We present the result of physical studies for three integral-type burnable absorbers of gadolinia, erbia and IFBA, in the hexagonal fuel assembly. The analysis of nuclear characteristics for gadolinia and IFBA cases shows that the spectrum hardening of hexagonal fuel assembly compared to rectangular one leads to smaller reactivity hold-down worth(RHW) and less change of MTC in the negative direction per insertion of one burnable absorber rod. Erbia case, on the other hand, exhibits reversed trend in RHW and MTC due to the enhanced absorption of large resonance of Erbium at 0.5 eV It turns out to be that Erbia performs best in terms of minimizing the peak pin power and maintaining as more negative MTC as practically attainable during the entire operational phase, and IFBA provides the least residual reactivity penalty at EOC. Therefore, we take Erbium as the suitable burnable absorber and provide optimal designs of 60, 120, 180, 240 and 300 erbia-shimmed hexagonal fuel assemblies with regard to minimizing the peak pin power.

• Nuclear Engineering and Technology
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• 제44권2호
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• pp.113-150
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• 2012

The point we made in this paper is that, although detailed and precise three-dimensional (3D) whole-core transport calculations may be obtained in the future with massively parallel computers, they would have an application to only some of the problems of the nuclear industry, more precisely those regarding multiphysics or for methodology validation or nuclear safety calculations. On the other hand, typical design reactor cycle calculations comprising many one-point core calculations can have very strict constraints in computing time and will not directly benefit from the advances in computations in large scale computers. Consequently, in this paper we review some of the deterministic 3D transport methods which in the very near future may have potential for industrial applications and, even with low-order approximations such as a low resolution in energy, might represent an advantage as compared with present industrial methodology, for which one of the main approximations is due to power reconstruction. These methods comprise the response-matrix method and methods based on the two-dimensional (2D) method of characteristics, such as the fusion method.

• 한국광학회:학술대회논문집
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• 한국광학회 2000년도 제11회 정기총회 및 00년 동계학술발표회 논문집
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• pp.126-127
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• 2000

Resonance fluorescence is the manifestation of the interaction between the physical system under consideration and the vacuum-field fluctuation. The fluorescence spectrum provides such physical informations as the energy-level structure of the system, instabilities and relative populations of the energy levels, etc.. One of the typical fluorescence spectra is the Mollow triplet appearing when two-level atoms are driven by a strong coherent field in free space$^{(1)}$ . In the weak field limit, the singlet instead of the triplet is obtained with a reduced linewidth due to the squeezing of one quadrature phase of the induced atomic dipole$^{(2)}$ . On the other hand, when the atoms are put inside a cavity rather than in free space, a doublet spectrum due to the vacuum Rabi-splitting is achieved, showing clearly the coupling of atoms and the cavity in the single-quantum limit$^{(3)}$ . (omitted)

• Archives of Reconstructive Microsurgery
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• 제23권2호
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• pp.82-85
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• 2014

Upper extremity replantation is relatively less commonly performed than finger or hand replantation. We have experienced one case of forearm replantation and one case of upper arm replantation. After the replantation, limb volume at the biceps brachii muscle level below the replantation level appeared to be appropriate, however, the motor function of the muscles and the sensitivity were disappointing. For replantation of forearm and upper arm, restoration of the motor function and sensitivity of the extremity below the amputation level as well as the morphologic reconstruction have to be considered.

• 한국학교보건학회지
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• 제20권2호
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• pp.59-68
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• 2007

Purpose: The purpose of this study was to investigate the difference of sexual behaviors of college students according to internet pornography contact. Methods: Subjects consisted of 472 students of K college located in chungcheongbuk-do. The data were collected through a self-administered questionnaire from May, 21 to May, 31, 2007. Results: Eighty-seven percent (87.3%) of respondents contacted internet pornography. As for the first time they contacted it, forty-eight percent(48.3%) contacted it when they were middle school students. Forty-three percent(43.6%) contacted it one time per several months and twenty-one percent(21.2%) contacted it within 10 minutes. Sexual behaviors(hand grasping, hugging, kiss, masterbation, coitus, pregnancy, love expression in public place) showed significant differences according to Internet pornography contact experience, period, frequency, and time. Conclusion: College administration should investigate sexual behavior patterns according intemet pornography contact and provide all college students regular sexual health promotion program.

• 대한미생물학회지
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• 제16권1호
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• pp.13-18
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• 1981

Total 984 specimens were collected from sweages(130 specimens) and human rectal swabs(854 specimens) during period from October 1979 to November 1980 in Korea. Sixteen strains of salmonella were isolated from the human rectal swabs at the St. Mary's Hospital in Dae Jeon. They were confirmed into fifteen strains of S. typhi, one strain of S. paratyphi A. In other hand, fourty three strains of Shigella had been isolated from the stool specimens. They were typed as thirty four strains of Shigella flexneri, five strains of Shigella sonnei and one strain of Shigella dysenteriae. However, 16 strains of Vibrio eltor had been isolated from patients and carriers in the first epidemic areas in Chunla Namdo in September 1980. The serotype of isolated strains was determined as a Inaba which was resistant to the Mukerjee phage group IV but was susceptible to El Tor phage groupe I and II. Authors had been concluded that the strains were certain to be identified with Vibrio cholerae biotype El Tor.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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• pp.87-89
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• 2006

A handover for DVB-H(Digital Video Broadcasting for Handheld) is the action of switching a receiver from receiving one signal to receiving another, when moving between the border of their coverage areas. This paper proposes new approaches for improving loss-free handover performance in the DVB-H networks. The proposed handover schemes are targeted to two different DVB-H receivers: One is for the receivers equipped with GPS devices. The other is for ones without GPS support. The first handover approach modifies the cell description table(CDT) proposed in the literature[1]. The second proposes a novel handover region estimation technique based on a new handover map table(HMT). This new handover approach estimates a predefined hand over region described in the HMT using measured RSSIs signal patterns. The estimation success rate is simulated and the benefits of the proposed method are discussed considering time and power consumption.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.165-169
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• 2000

A simple method was suggested to calculate the stress intensity factor for a one-sided patched crack with finite thickness. To consider out-of-plane bending effect resulting from the load-path eccentricity, the spring constant as a function of the through-thickness coordinate z was calculated from the stress distribution in the un-cracked plate, ${\sigma}_{yy}(y=0,\;z)$, and the displacement for the representative single strip Joint, $u_y(y=0,\;z)$. The stress Intensity factors were obtained using Rose's asymptotic solution approach and compared with the finite element results. In short crack region, two results had a little difference. However, two results were almost same in long crack region. On the other hand, the stress intensity factor using plane stress assumption was more similar to finite element result than plane strain condition.

• 전력전자학회논문지
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• 제17권2호
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• pp.142-149
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• 2012

The independently regulated dual-output LLC resonant converter using only one power stage and one control IC is proposed in this paper. The conventional dual-output LLC resonant converter requires the extra non-isolated DC/DC converter to obtain the tightly regulated slave output voltage, which results in the low power conversion efficiency and high production costs. On the other hand, since the proposed converter controls the master and slave output voltages by pulse width modulation(PWM) and pulse frequency modulation(PFM), it can achieve tightly regulated dual output voltages without the additional non-isolated DC/DC converter. Therefore, it features a high efficiency and low cost. To confirm the validity of the proposed converter, theoretical analysis and experimental results from a 40W LED driver prototype are presented.

• Journal of Chest Surgery
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• 제26권6호
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• pp.492-495
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• 1993

We experienced one case of surgical treatment of abdominal aortic aneurysm using retroperitoneal approach. The transperitoneal route has been the standard surgical approach for elective and emergency treatment of aneurysmal or occlusive disease. Among its cited advantages for aortic reconstruction are familarity with the exposure, easy access to the infrarenal aorta and iliac vessels, possibility of simultaneous inspection of the intra-abdominal viscera, and speed of opening and closure.Despite the proved versatility of the transperitoneal approach, it is commonly associated with prolonged ileus, increased third space fluid loss, and significant pulmonary complications. The retroperitoneal approach, on the other hand, has many advantages; excellent exposure for the repair of juxtarenal or suprarenal abdominal aortic aneurysms and visceral vessel occlusive disease, fewer postoperative complications, decreased postoperative third-space fluid losses from intraoperative evaporation and ileus, and improved postoperative pulmonary function. Atherosclerosis was most common cause of abdominal aortic aneurysm. Dacron graft[18mm] was replaced successfully.Postoperative course was uneventful and he was discharged in good condition.