• 한국재료학회지
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• 제13권3호
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• pp.185-190
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• 2003

Titanium dioxide films were prepared by RF sputtering method on glass for various oxygen partial pressures at power 270 W. The crystal structure, photocatalytic property and the hydrophilicity of $TiO_2$thin film the deposition conditions were investigated. Crystallized anatase phase was observed in $TiO_2$film deposited at the ratio of oxygen partial pressure 10% and 20% for 2 hrs. As the increase of deposition time, the grain size and void size of $TiO_2$film have increased and also $V_2$films have been good crystallinity. The ultraviolet-visible light absorption of $TiO_2$films was increased with increasing of deposition time and occured chiefly at the wavelength between 280 and 340 nm. The absorption band was shifted to a longer wave length as deposition time increased. Water contact angle on the X$TiO_2$film of anatase structure was decreased with increasing ultraviolet illumination time and became lower than $11^{\circ}$ from $83^{\circ}$. When hydrophilic $TiO_2$film changed by enough ultraviolet illumination was stored in the dark, the film surface gradually turned to hydrophobic state.

• 한국전산유체공학회지
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• 제19권3호
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• pp.91-97
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• 2014

A high resolution numerical method aimed at solving cavitating flow was proposed and applied to gas-liquid two-phase shock tube problem with arbitrary void fraction. The present method with compressibility effects employs a finite-difference 4th-order Runge-Kutta method and Roe's flux difference splitting approximation with the MUSCL TVD scheme. The Jacobian matrix from the inviscid flux of constitute equation is diagonalized analytically and the speed of sound for the two-phase media is derived by eigenvalues. So that the present method is appropriate for the extension of high order upwind schemes based on the characteristic theory. By this method, a Riemann problem for Euler equations of one dimensional shock tube was computed. Numerical results of high speed flow phenomena such as detailed observations of shock and expansion wave propagations through the gas-liquid two-phase media and some data related to computational efficiency are made. Comparisons of predicted results and solutions at isothermal condition are provided and discussed.

• 디자인학연구
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• 제12권3호
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• pp.29-40
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• 1999

Walter Gropius, famous architect of Bauhaus, once treated of pure mind which was revealed in the system of object and its phenomena through sense of sight while examining material being and illusive being. And Thomas Aquinas said that man can have a creative power only with modest mental state void of prejudice saying that he expected God to come to him after his soul went out of him. The same thing was said by so many great philosophers and thinkers other than him. I think his saying, "God comes after Soul's escape from the body for a new creation", has a real truth for all times and places and beauty itself beyond expression. Why\ulcorner The reason why the saying is so true is because it has a Yin and Yang Idea, that is, the Soul means a dark spirit correspondent to Yin between both oriental ideas and God does a bright spirit correspondent to Yang between them. By reason of this idea, I would like to assert that we should take it granted that we stand in need of the same bright Yang's spirit as God has for the new creation, and let the Yang's bright spirit come to our minds. We can call it divine 'Providence', or call it God's guidance, which we cannot help accepting as a man's fatality. As God was pleased after he made man and all the creatures by dint of his design, so man was pleased after he made everything he needed by the same design that he accepted from God. In spite of pleasure of different dimensions from what God and Man has each other, their way of empathies were all the same. In this paper I compared a worldly lower conception by which man designed his products for his sensuous satisfaction with a higher conception by which God designed his creatures for his mental satisfaction. I intended to infer what destined relation there must be between both God's and man's creations, trying to remind designers that they have to confess to have not so divine a providence as God has for creation because I think the real truth is that they had regarded their works of product design as a routine occurrence for their physical convenience in the industrial plans.ial plans.

• 한국도로학회논문집
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• 제18권5호
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• pp.21-29
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• 2016

PURPOSES : The purpose of this study is to suggest a specific investigation guideline to decide priority of repairing old concrete pavements that pile up substantially. METHODS : In this study, a principle of division of homogeneous sections was proposed to reflect the characteristics of the pavement reasonably in the specific investigation results. In addition, a checklist and guideline of field investigation were suggested for the old concrete pavement sections, which require inspection toward their durability and structural performance. Furthermore, the items of laboratory test necessary to the old concrete pavement were suggested based on the existing laboratory test considering characteristics of the old concrete pavement. The present condition of the old concrete pavement could be analyzed by the test results. RESULTS : A method of division of homogeneous sections suitable for the specific investigation of the old concrete pavement was suggested. The proportions of distress severity of pavement sections were compared by distress type to figure out the present state of the old concrete pavement. Scaling, durability cracking (or alkali-silica reaction), and longitudinal spalling were selected as the most severe distress types. The detailed positions of the sections were also suggested. The checklist of the specific investigation was categorized by field survey and laboratory test, and its evaluation criteria were proposed. The three types of the sections of durability cracking (or alkali-silica reaction), bridge connection, and asphalt overlay were selected as the sections of the field survey. The compressive strength, void structure, and chloride penetration depth were suggested as the items of the laboratory test. CONCLUSIONS : A fundamental level of the guideline was suggested in this study to resolve the problem of old concrete pavement. Appropriate guidelines related to the repair of the old concrete pavement should be provided by performing additional research efforts.

• 한국재료학회지
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• 제13권7호
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• pp.429-435
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• 2003

In this study the new creep test using miniaturized specimen(10${\times}$10${\times}$0.5 ㎣) was performed to evaluate the creep characteristics for degraded materials of 2.25Cr-1Mo steel. For this creep test, the artificially aged materials for 330 hrs and 1820hrs at $630^{\circ}C$ were used. The test temperatures applied for the creep deformation of miniaturized specimens was X$630^{\circ}C$ and the applied loads were between 45 kg∼80 kg. After creep test, macro- and microscopic observation were conducted by the scanning electron microscope(SEM). The creep curves depended definitely on applied load and microstructure and showed the three stages of creep behavior like uniaxial tensile creep curves. The load exponents of virgin, 330 hrs and 1820 hrs materials based on creep rate showed 14.8, 9.5 and 8.3 at $550^{\circ}C$ respectively, The 1820 hrs material showed the lowest load exponent and this behavior was also observed in the case of load exponent based on creep rupture time. In contrast to virgin material which exhibited fined dimple fractography, a lot of carbides like net structure and voids were observed on the fractography of degraded materials.

• Journal of Korean Biological Nursing Science
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• 제9권2호
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• pp.135-142
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• 2007

Purpose: This study was conducted to investigate degree of stress level in CCU patients, and to give a baseline data in developing nursing intervention program to reduce the stress. Method: Subjects of this study were the 100 hospitalized patients of C University Hospital in Seoul City from February to December 2003. The collected data was analyzed by using the SAS program: t-test, Scheff$\acute{e}$ test, and ANOVA analysis were employed to find differences in stress level. Result: The highest stress factor was 'Concern', and next were 'Dependency & limitation', 'Uncertainty', 'Treatment procedure', 'Sleep disturbance', 'Environment' in order. The perceived stress level of CCU patients was 1.65 scores; the highest scored item was 'have to void urine and feces on the bed', next were 'have to use the toilet bowel lying on the bed' in order. The stress level according to characteristics of the subjects was significantly different with the marital status, the presence of religion, the hospitalized days, the economic status, and the admission experience. Conclusion: The stress level of patients in the coronary care unit was high in concern of a disease, family and economic state, in limitation and dependency, and in uncertainty about prognosis of a disease. Further researches are necessary to develop and apply the intervention method of reducing stress level of CCU patients. In addition studies on family members of CCU patients are also recommended.

• 한국지반공학회논문집
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• 제21권6호
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• pp.5-18
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• 2005

본 연구에서는 배수면으로부터의 거리에 따라 점진적으로 진행되는 압밀이 차후의 압밀 거동에 미치는 영향에 대하여 고찰하였다. 이를 위해 압밀진행에 따른 위치 별 투수계수 및 부피압축계수의 변화를 고려할 수 있는 유한차분 압밀해석기법 및 프로그램을 개발하였다. 개발된 해석 프로그램을 이용하여 간극비 변화에 따른 투수계수와 부피압축 켸수의 변화 정도가 다른 다양한 특성의 지반에 대하여 연직배수재가 설치된 모형지반의 압밀거동을 분석하였다. 또한 실제 지반조건에서의 영향 정도를 살펴보기 위하여, 낙동강 하구의 정규압밀 점성토 및 재성형 카올리나이트의 지반 특성을 근간으로 입력치를 결정, 해석을 수행하여 위치 별 점진적 압밀에 의한 영향을 분석하였다. 해석 결과 점진적 압밀 진행에 따른 압밀 지체가 현장의 압밀 거동 이해에 매우 중요하며, 또한 압밀 초기에, 소성성이 크고, 재하하중이 클수록 현저하게 나타남을 알 수 있었다.

• 한국실내디자인학회논문집
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• 제22호
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• pp.61-68
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• 2000

This paper illustrates what the reality of architectural concepts, materials, notions and phenomena are as central questions of contemporay space design. These issues form the goal of modern space design which should attain to the reality of an era when non-real values prevail. Despite the trends of an everchanging and ephemeral dominating quality in architecture for the last ten years, architects still aim to contruct everlasting space on earth. The trends of dematerialization in today's space design can be substantiated in spatial-temporal dimensions as follows. First of all, ephemeral architecture with concepts of hypothetical temporality, everchanging architecture in fluidity, and the transparent architecture with the floating and overlapping image can be analyzed in the dimension of 'time'. In terms of 'space', void quality for the expression of emptiness, neutral space by the simplified and summarized forms, expanded space through ambiguous boundaries and spatial repetition can becharacterized and also be intended strategies for lightness, state of flux, ambiguity, paradox etc., lead modern space design along that path. As this point, we need to pay attention to the so-called 'hypersurface' concept proposed by Stephen Perella. Hypersurface is a sort of cladding sheathing existence independent from the primary structure. With it, the integration between form and image can be achieved. Sometimes hypersurface can be a strategical screen for image projection, a cognitive receptor for surroundings as well as a catalyst for information and communication systems. When the situation dematerializes more and more as the years go on, the concept of hypersurface can be an inclusive method between the phenomenological form in architecture and its self recipient image. Permissive atmospheres created between them in contemporary space design and new paradigms emerged with digital technology will further reinforce the human space's dynamism.

• Nuclear Engineering and Technology
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• 제48권4호
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• pp.847-858
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• 2016

An overview is given on the work of the Laboratory of Nuclear Energy Systems at ETH, Zurich (ETHZ) and of the Laboratory of Thermal Hydraulics at Paul Scherrer Institute (PSI), Switzerland on tight-lattice bundles. Two-phase flow in subchannels of a tight triangular lattice was studied experimentally and by computational fluid dynamics simulations. Two adiabatic facilities were used: (1) a vertical channel modeling a pair of neighboring sub-channels; and (2) an arrangement of four subchannels with one subchannel in the center. The first geometry was equipped with two electrical film sensors placed on opposing rod surfaces forming the subchannel gap. They recorded 2D liquid film thickness distributions on a domain of $16{\times}64$ measuring points each, with a time resolution of 10 kHz. In the bubbly and slug flow regime, information on the bubble size, shape, and velocity and the residual liquid film thickness underneath the bubbles were obtained. The second channel was investigated using cold neutron tomography, which allowed the measurement of average liquid film profiles showing the effect of spacer grids with vanes. The results were reproduced by large eddy simulation + volume of fluid. In the outlook, a novel nonadiabatic subchannel experiment is introduced that can be driven to steady-state dryout. A refrigerant is heated by a heavy water circuit, which allows the application of cold neutron tomography.

• Journal of Korean Biological Nursing Science
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• 제18권3호
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• pp.127-134
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• 2016

Purpose: The purpose of this study was to investigate the physiological index, anxiety and depression by the severity of lower urinary tract symptoms in patients with benign prostatic hyperplasia. Methods: This research was conducted from the 4th to the 27th of May in 2016 on112 patients with benign prostatic hyperplasia. The data were analyzed using a chi-square test, ANOVA, and Pearson Correlation Coefficients. Results: The results demonstrated a difference depending on the dysuria period of each lower urinary tract symptom, marital status, occupation and perceived health state of the patient. The physiological index by lower urinary tract symptoms showed a difference in the maximum flow rate, amount of post-void residual urine and Prostate-Specific Antigen (PSA), and anxiety and depression factors also revealed a difference. Lower urinary tract symptoms showed a positive correlation to the amount of post voided residual urine and PSA, a negative correlation to the maximum flow rate and also indicated a positive correlation to depression. Conclusion: The results of the study belonging to the moderate and severe categories were high when the result was based on the categorization of subjects with benign prostatic hyperplasia with lower urinary tract symptoms. Considering that depression levels increase as the symptom intensifies and the anxiety score is also high with mild symptoms, psychological support intervention is needed when a pattern of benign prostatic hyperplasia appears.