• 대한수학회보
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• 제53권5호
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• pp.1497-1530
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• 2016

External barrier options are two-asset options with stochastic variables where the payoff depends on one underlying asset and the barrier depends on another state variable. The barrier state variable determines whether the option is knocked in or out when the value of the variable is above or below some prescribed barrier level. This paper derives the explicit analytic solution of the chained option with an external single or double barrier by utilizing the probabilistic methods - the reflection principle and the change of measure. Before we do this, we examine the closed-form solution of the external barrier option with a single or double-curved barrier using the methods of image and double Mellin transforms. The exact solution of the external barrier option price enables us to obtain the pricing formula of the chained option with the external barrier more easily.

• Nuclear Engineering and Technology
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• 제54권6호
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• pp.2135-2146
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• 2022

A nuclear energy facility is one of the most critical facilities to be safely protected during and after operation because the physical destruction of its barriers by an external attack could release radioactivity into the environment and can cause harmful effects. The barrier walls of nuclear energy facilities should be sufficiently robust to protect essential facilities from external attack or sabotage. Physical protection system (PPS) vulnerability assessment of a typical small nuclear research reactor was carried out by simulating an external attack with a tri-nitro toluene (TNT) shaped charge and results are presented. The reinforced concrete (RC) barrier wall of the research reactor located at a distance of 50 m from a TNT-shaped charge was the target of external attack. For the purpose of the impact assessment of the RC barrier wall, a finite element method (FEM) is utilized to simulate the destruction condition. The study results showed that a hole-size of diameter 342 mm at the front side and 364 mm at the back side was created on the RC barrier wall as a result of a 143.35 kg TNT-shaped charge. This aperture would be large enough to let at least one person can pass through at a time. For the purpose of the PPS vulnerability assessment, an Estimate of Adversary Sequence Interruption (EASI) model was used, which enabled the determination of most vulnerable path to the target with a probability of interruption equal to 0.43. The study showed that the RC barrier wall is vulnerable to a TNT-shaped charge impact, which could in turn reduce the effectiveness of the PPS.

• 대한한의학회지
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• 제29권1호
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• pp.117-133
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• 2008

Objectives : Since ancient times, Koreans have applied medicinal spabaths for treatment of various diseases. The objective of this study was to investigate the effect of strontium, one of the common ingredients of such baths, experimentally on acute skin barrier damage. Materials and Methods : Male hairless mice, average weight 20g, were divided into six groups. Each group consisted of five mice. The first was the normal, non-treated group. The second was the control group with acute skin barrier damage intentionally induced by TS. The third was the Ba-Sr1 group bathed in 1mg/L strontium chloride before and after inducing acute skin barrier damage by TS. The fourth was the Ba-Sr7 group bathed in 7mg/L strontium chloride before and after inducing acute skin barrier damage by TS. The fifth was the Sr1 group bathed in 1mg/L of strontium chloride only after intentionally inducing acute skin barrier damage by TS. The sixth was the Sr7 group bathed in 7mg/L of strontium chloride only after intentionally inducing acute skin barrier damage by TS. External changes of skin, skin erythema level, transepidermal water loss level, and GOT and GPT level of each group were checked immediately before and after TS, 3 hrs, 5 hrs and 24 hrs after inducing acute skin barrier damage. Then, tissue samples were made and examined for damage to epithelial cells, stratum corneum, change of mucous polysaccharide in dermis and amount of mast cells. Statistical analysis was performed by one way-ANOVA, Scheffe and Duncan for a post hoc test and pairwise comparison for comparing for difference between each time. Statistical significance was achieved if the probability was less than 5% (p<0.05) Results : 1. From skin erythema and TEWL level indicating the function of the skin barrier, we can know that it is helpful to the skin barrier to bathe in a water solution including a low concentration of strontium. 2. In the control group with acute skin barrier damage induced by TS, skin barrier damage persisted until 3-5 hrs and recovered after 5-24 hrs. Differently from the control group, in the case of taking a bath in a water solution including strontium, skin barrier damage recovered after only 3-5 hrs. Therefore, the bath with a water solution including strontium can promote recovery of the skin barrier. 3. Bathing in water solution including a higher concentration of strontium was more beneficial to recovery of skin barrier damage. 4. There was no influence on serum GOT and GPT from bathing in a water solution including strontium. Conclusions : The strontium was effective for recovery and mitigation of acute skin barrier damage induced by tape stripping. I suggest that strontium (Sr) can be used as an external treatment medicine, addedinto bath water to treat acute skin barrier damage.

• 경영과정보연구
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• 제36권2호
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• pp.223-237
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• 2017

전환장벽은 고객의 이탈을 막는다는 점에서 주로 긍정적인 측면이 강조되었으나, 최근에는 기업이 설정한 전환장벽이 장기적으로 해로울 수 있음이 논의되기 시작하였다(Jones et al. 2000; 정윤희, 2012). 전환장벽의 부정적 영향에 관한 기존연구에서는 전환장벽이 소비자의 전환의 자유를 방해한다는 점에서 부정적 심리반응을 이끌 수 있음은 보여주었으나, 당장 기업에 줄 수 있는 부정적인 영향에 대한 논의는 부족하였다. 따라서 본 연구에서는 전환장벽으로 인해 전환을 못하는 상황에 서비스 실패상황에 관한 연구를 적용하여 소비자들의 전환장벽에 대한 부정적 감정과 불평행동에 대한 연구를 진행하고자 하였다. 전환을 어렵게 하는 전환장벽의 귀인(내적 혹은 외적)에 따라 후회와 원망을 경험하게 되고 이는 수용, 불평행동, 부정적 구전으로 이어질 것으로 가정하였다. 구조방정식 모형을 이용해 가설 검증한 결과, 내적귀인은 후회에 긍정적 영향을 주고, 외적귀인은 원망에 긍정적 영향을 주는 것으로 나타났다. 그리고 후회는 수용과 불평행동에 영향을 주고, 원망은 불평행동과 부정적 구전에 긍정적 영향을 미침을 확인하였다. 이러한 결과는 전환장벽이 고객들의 부정적 감정과 불평행동을 이끌어 기업에 즉각적 피해를 줄 수 있음을 보여줌으로써 기존연구를 확장하고 있으며, 전환장벽에 대한 신중한 실무적 활용을 시사한다.

• 한국재료학회지
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• 제12권3호
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• pp.200-204
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• 2002

We fabricated TMR devices which have double oxidized tunnel barrier using plasma oxidation method to form homogeneously oxidized AlO tunnel barrier. We sputtered 10 $\AA$-bottom Al layer and oxidized it by varying oxidation time for 5, 10, 20 sec. Subsequent sputtering of 13 $\AA$ - Al was performed and the matallic layer was oxidized for 120 sec. The electrical resistance changed from 700$\Omega$ to 2700$\Omega$ with increase of oxidation time, while variation of MR ratio was little spreading 27~31% which is larger than that of TMR device of ordinary single tunnel barrier. We calculated effective barrier height and width by measuring I-V curves, from which we found the barrier height was 1.3~1.5 eV, sufficient for tunnel barrier, and the barrier width(<16.2 $\AA$) was smaller than that of directly measured value by the tunneling electron microscopy. Our results may be caused by insufficient oxidation of Al precursor into $Al_2O_3$. However, double oxidized tunnel barriers were superior to conventional single tunnel barrier in uniformity and density. We found that the external magnetic field to switch spin direction of ferromagnetic layer of pinned layer breaking ferro-antiferro exchange coupling was increased as bottom layer oxidation time increased. Our results imply that we were able to improve MR ratio and tune switching field by employing double oxidized tunnel barrier process.

• 대한한방소아과학회지
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• 제35권4호
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• pp.156-166
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• 2021

Objectives The purpose of this study is to confirm the regulate effect of T helper (Th) 2 differentiation that Baekho-tang extract may produce to improves skin lipid barrier damages. Methods Four-weeks-old NC/Nga mice were divided into four groups: control group (Ctrl, n=10), lipid barrier eliminated group (LBE, n=10), Dexamethasone treatment after lipid barrier elimination group (DxT, n=10), and Baekho-tang extract treatment group after lipid barrier elimination group (BHTT, n=10). Baeko-tang extract was administered for 3 days after removal of the skin fat barrier in BHTT group. Then, we identified changes in external symptoms of the skin, factors affecting skin barrier such as potential of hydrogen (pH), filaggrin (FLG), transepidermal water loss (TEWL) and Th2 differentiation factors like Interleukin (IL)-4, Kallikrein Related Peptidase 7 (KLK7) and protease activated receptor 2 (PAR-2) through our immunohistochemistry. Results After lipid barrier elimination, the reduction of morphological skin inflammations was less in BHTT group than in LBE group and DxT group. Also, pH and TEWL were significantly decreased with BHTT group. However, FLG was significantly increased in BHTT group compared to LBE, DxT, and Ctrl group. All kinds of Th2 differentiation factors (IL-4, KLK7 and PAR-2) were also decreased in BHTT compared to the LBE and DxT. Conclusions As a result of this study, BHT administration decreased pH, TEWL, and increased FLG, thus participating in recovering damaged skin barrier. Since Th2 differentiation factors were decreased as well, BHT's regulatory effect in sequential immune reactions may be a possible explanation of how it enhances recovery of the damaged lipid barrier.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.287.2-287.2
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• 2016

Silicon has considerably good characteristics on electron, hole mobility and its price. With 2-D sinlge-layer Graphene/n-Si heterojunction solar cell shows that in one sun condition exhibit power conversion efficiency(PCE) of 10.1%. This photovoltaic effect was achieved by applying gate voltage to the Schottky junction of the heterostructure solar cell. Energy band diagram shows that Schottky barrier between Si and graphene can be adjust by the external electric field. because of the fermi level of the graphene can be changed by external gate voltage, we can control the Schottkky barrier of the heterostructure solar cell. The ratio between generated power of solar cell and consumption electrical power is remarkable. Since we use the graphene as the top gate electrode, most of the sun light can penetrate into the active area.

• 대한한방소아과학회지
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• 제36권1호
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• pp.57-64
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• 2022

Objectives The purpose of this study is to confirm the regulate effect of T helper (Th) 2 differentiation that Sabaek-san extract may produce to improves skin lipid barrier damage. Methods Four-weeks-old NC/Nga mice were divided into four groups: control group (Ctrl, n=10), lipid barrier eliminated group (LBE, n=10), Dexamethasone treatment after lipid barrier elimination group (DXT, n=10), and Sabaek-san extract treatment group after lipid barrier elimination (SBT, n=10). Sabaek-san extract was administered for 3 d after removal of the skin fat barrier in SBT group. Then, we identified changes in external symptoms of the skin, factors affecting skin barrier such as potential of hydrogen (pH), filaggrin, transepidermal water loss (TEWL) and Th2 differentiation factors like Interleukin (IL)-4, Kallikrein Related Peptidase 7 (KLK7), and protease activated receptor 2 (PAR-2) through our immunohistochemistry. Results After lipid barrier elimination, the reduction of morphological skin inflammations was less in SBT group than in LBE and DXT group. Also, pH and TEWL were significantly decreased with SBT group. However, filaggrin was significantly increased in SBT group compared to LBE, DXT, and Ctrl group. All kinds of Th2 differentiation factors (IL-4, KLK7 and PAR-2) were also decreased in SBT compared to the LBE and DXT. Conclusions As a result of this study, SBT administration decreased pH, TEWL, and increased filaggrin, thus participating in recovering damaged skin barrier. Since Th2 differentiation factors were decreased as well, SBT's regulatory effect in sequential immune reactions may be a possible explanation of how it enhances recovery of the damaged lipid barrier.

• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
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• pp.570-577
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• 2003

The importance of cornified envelope (CE)-bound lipids to epidermal barrier function is increasingly being recognized. In the present study, we intentionally damaged the cornified layer of hairless mice by ultraviolet irradiation and sodium dodecyl sulfate (SDS) treatment, and assessed the changes in epidermal barrier function by measuring Trans Epidermal Water Loss (TEWL). We also measured changes in the amount of CE-bound lipids using thin layer chromatography (TLC). The results showed that both treatments increased TEWL and decreased CE-bound lipids (omega-hydroxy cerami de and omega-hydroxy acid). In addition, investigation of the chronological changes in TEWL revealed an inverse relationship between TEWL and CE-bound lipids, and a correlation between CE-bound lipids and epidermal barrier function. We then measured the amount of CE-bound lipids in the cheek and the medial side of the upper arm in humans. The results showed that because the cheek receives external stimulation on a daily basis, the amount of CE-bound lipids was significantly lower, while the level of TEWL was higher. These observations, together with those from the animal study, indicate that CE-bound lipids are related to epidermal barrier function.

• 한국도로학회논문집
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• 제15권6호
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• pp.33-39
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• 2013

PURPOSES : This research investigates traffic noise characteristics as change the transverse rumble strips shape from rectangular to cylinder at toll plaza of highway. METHODS : The traffic noise was investigated at two different places at toll plaza of highway. One is modified grooving, another is employed cylinder shape of TRS instead of rectangular shape of TRS. A measurement of traffic noise was conducted at same location and time period. The traffic volume information was gotten from office of highway office and vehicle speed was measured by speed measuring device. The traffic noise measurement was conducted from 13:00 to 23:00 and by pass-by method. Also, the traffic noise was measured behind noise barrier. Various distance from noise barrier(7.5m, 30m, 50m) and different heights(1.2m, 3m, and 5m) were parameter for measurement of traffic noise in this study. RESULTS : The class 1 vehicle was contributed from traffic volume which was increased 1,500. However, the distribution of traffic speed didn't change compare to previous investigated period. From this study, It was found that the external traffic noise was changed as function of geometric shape of TRS. The external noise from modified grooving was less than 1.2dB(A) of the current TRS. A difference of traffic noise was 20dB(A) before and after barrier. It came from a noise barrier effect as reduction of traffic noise. According to investigate a traffic noise distribution near barrier, there is similar noise characteristic as function of height at 7.5m distance from noise barrier. Also, There is no different traffic noise between 30m and 50m from source of the noise of sound barrier. CONCLUSIONS : Based on this traffic noise investigation result, there is a clear characteristic difference as changed TRS shape. The traffic noise was reduced by changed TRS shape. Specially, traffic noise was decreased although the traffic volume was increase for same investigation time and period. It is implied that cylinder type of TRS significantly reduces the traffic noise. The specification of various TRS will be studied in the future.