• Title/Summary/Keyword: Scale-free

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Estimatation of Mean Velocity from Surface Velocity (표면유속을 이용한 평균유속 추정방법의 개발)

  • Roh, Young-Sin;Yoon, Byung-Man;Yu, Kwon-Kyu
    • Journal of Korea Water Resources Association
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    • v.38 no.11
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    • pp.917-925
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    • 2005
  • LSIV (Large Scale Image Velcocimetry) Is one of the image-based velocity measurement techniques. Since it measures surface velocities, it gives simple and inexpensive way to measure velocity, compared to other methods. Because of these advantages, there have been many studies to apply LSIV to the river discharge measurement in the field. Measuring the discharge by using LSIV requires a method which converts a surface velocity to a mean velocity In the present study, experiments and analysis of vortical velocity profile of open-channel flow in various conditions were performed to develop methods which estimate a mean velocity from a surface velocity. The result of this experiment reveals that velocity-dip phenomena occur at free-surface layer in open channel flow and Froude number affects more than bed roughness does. Two methods for estimating the mean velocity were proposed. One is to correct the wake law's profiles by using the difference of surface velocity from the mean velocity, and the other is to use the ratio of mean and surface velocities. The result of applying these methods in an experiment shows that they are quite accurate having an error of approximately $6\%$ only.

Antioxidant Activity of Pyrus serotina Fruit in Different Cultivars and Parts (배 품종 및 부위별 항산화 활성)

  • Jin, Young-Ook;Song, Won-Seob
    • Korean Journal of Plant Resources
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    • v.25 no.4
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    • pp.498-503
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    • 2012
  • The aim of this study is to compare the total polyphenol, total flavonoid, and antioxidative activity among 5 cultivars of Korean pears cultivated in Korea. As a result of the analysis for the phenolic substance of 5 cultivars, such as Wonwhang, Sunwhang, Whangkeumbae, Chuwhang, and Shingo, the content of total polyphenol was higher in Shingo and Chuwhang, and the content of total flavonoid showed higher levels in Wonwhang and Sunwhang. In addition, this study found that DPPH radical-scavenging ability was the highest in Shingo and that the part of fruit skin showed more favorable reaction to radical ability than fruit flesh. It was also found that much better antioxidative activity was shown for the methanol solvent extraction than for the ethanol solvent extraction. The nitrite-scavenging ability showed the best for Wonwhang and Chuwhang of the cultivars and much better reaction for the methanol solvent extraction than for the ethanol solvent extraction just like the case of DPPH radical-scavenging ability. Further, nitrite-scavenging ability appeared much better reaction for the fruit skin than for the fruit flesh, and antioxidative activity dropped for the higher the range on the pH scale. From the results of this study, Korean pears are worthy of developing as a natural functional food and substance for beauty treatment through the research on bioactivity.

A Study on Development of Robot for Mutual Communication and Education of Students with Health Impairments (건강장애 학생의 상호소통 및 교육을 위한 로봇 개발에 대한 연구)

  • Ryu, Gun Jae;Kang, Jung Bae;Kim, Chang Geol;Kim, Kyung Sik;Song, Beong Seop
    • Journal of Korea Society of Industrial Information Systems
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    • v.19 no.5
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    • pp.15-24
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    • 2014
  • In 2005, there was a partial revision of the Act on the Promotion of Education for the Handicapped people, so that students with health impairments would be able to receive special education support. Since the amendment of the bill, to support them classified into weak people in education, education support systems have been proposed and settled so that they may receive the support for free. According to the pre-study, after the amendment of this bill, there has been many studies on the form of educational service to support them, and recently, there have been a lot of researches to investigate their satisfaction with the current services and draw its problems. And yet these studies have been carried out by the preceeding researchers at the drawing of problems, but have a limitation to present fundamental countermeasures to the problems. Therefore, this study attempted to understand the meaning of health impairment through the pre-study and investigate the forms of the services currently supporting them and analyze the problem of each service. In addition, to solve the identified problems, a new support system was proposed. In order to confirm the performance of the system, we design the user satisfaction survey composed of a Likert 5-point scale per each question, and to make the task, comparing stories and clapping for increasing quality of their subjective evaluation about the image and voice transmission when the user uses it. As a result, in the overall evaluation of the robot system, the average score of each question was recorded to 4.31 points, and through the two tasks, it was found that there were effective data transmission of image and voice.

Spatial Characters of Workplace and Everyday Life of Immigrant Workers in S. Korea (한국 이주노동자의 일터와 일상생활의 공간적 특성)

  • Choi, Byung-Doo
    • Journal of the Economic Geographical Society of Korea
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    • v.12 no.4
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    • pp.319-343
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    • 2009
  • This paper considers some kinds of socio-spatial constraints and strategies for overcoming them which immigrant workers in Korea have experienced in their work-place and life-space, with an analysis of questionnaire data and of direct interview materials on them. Though they appear somewhat satisfactory or positive with their work-place, this can be seen as a hypocritical or false attitude rather than a real one: they are forced to work with long hours (more than 70 hours per week) and rigid controls in the other' territory. Their daily life-spaces also are severe: they can be hardly embedded in an existing community with a sense of place due to serious institutional and interaction constraints, even though they seem to have a basic mobility to survive in life-spaces. In order to escape or alleviate such local constraints, they try to constitute multi-scalar (local, trans-regional, and transnational) networks, and to find informations and means to resolve or cope with them. However, this kind of endeavors of immigrant workers to make a trans-national network and social space has a limitation for them to be free entirely from constraints, which might be strengthened with a lack of geographical knowledge of them. Then immigrant workers in Korea live ineluctably with not only hybrid national identity but also with disturbed local identity in an aliened workplace and life-spaces.

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An evaluation of the composition and elements in Korean traditional interior space - On Choosa-Gotack in the Chosun dynasty - (한국전통 실내공간의 구성방법과 요소 분석을 통한 의미 고찰 - 조선조 추사고택을 중심으로 -)

  • 천진희
    • Archives of design research
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    • no.16
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    • pp.101-110
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    • 1996
  • CHOOSA GORACK which is a typical example of traditional houses in the CHO SEON dynasty consists of the four terraced builfing group. Among those,SADANG CHAI are located in the highest level,and SADANG CHAI and SADANG CHAI are toward south direction.It means that building orientation and level were influenced by the distinction of social level and the idea of ancester worship. Floor and ceiling level in the same building is different which was caused by the distinetion of social level in the CHO SEON dynasty and an ariental dual as a variety of openings,exposed ceilings,and furniture against a wall were creating a typical Korean visual harmony. Although the furniture and equipments were very important elements in ONDOL BANG the occupance ratio of these were low because the free space in BANG should be utilized effectively to accommodate the space variation.Both an AN CHAI and SARANG CHAI were composed by the standard space module called KAN.And interior elements were established by several factors such as the human scale,the behavior pattern in traditional sitting life style, and the lumber size of post and lintel construction of Korean house.BANG and DAE GHUNG, composed of KAN,were expanded and arranged side by side so that the natural light and ventilation through them could be used in the result of the kind of lay out,traffic circulation was disturved.In conclusion,CHOOSA GOTACK was formed by the sirect effice of the KOREAN penisula. However this study was based on one sample. It may not enough to deduct soild conclusion.Therefore continuous and farher study is needed for the sestemane evaluation.

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$TiO_2$ Thin Film Patterning on Modified Silicon Surfaces by MOCVD and Microcontact Printing Method

  • 강병창;이종현;정덕영;이순보;부진효
    • Proceedings of the Korean Vacuum Society Conference
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    • 2000.02a
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    • pp.77-77
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    • 2000
  • Titanium oxide (TiO2) thin films have valuable properties such as a high refractive index, excellent transmittance in the visible and near-IR frequency, and high chemical stability. Therefore it is extensively used in anti-reflection coating, sensor, and photocatalysis as electrical and optical applications. Specially, TiO2 have a high dielectric constant of 180 along the c axis and 90 along the a axis, so it is highlighted in fabricating dielectric capacitors in micro electronic devices. A variety of methods have been used to produce patterned self-assembled monolayers (SAMs), including microcontact printing ($\mu$CP), UV-photolithotgraphy, e-beam lithography, scanned-probe based micro-machining, and atom-lithography. Above all, thin film fabrication on $\mu$CP modified surface is a potentially low-cost, high-throughput method, because it does not require expensive photolithographic equipment, and it produce micrometer scale patterns in thin film materials. The patterned SAMs were used as thin resists, to transfer patterns onto thin films either by chemical etching or by selective deposition. In this study, we deposited TiO2 thin films on Si (1000 substrateds using titanium (IV) isopropoxide ([Ti(O(C3H7)4)] ; TIP as a single molecular precursor at deposition temperature in the range of 300-$700^{\circ}C$ without any carrier and bubbler gas. Crack-free, highly oriented TiO2 polycrystalline thin films with anatase phase and stoichimetric ratio of Ti and O were successfully deposited on Si(100) at temperature as low as 50$0^{\circ}C$. XRD and TED data showed that below 50$0^{\circ}C$, the TiO2 thin films were dominantly grown on Si(100) surfaces in the [211] direction, whereas with increasing the deposition temperature to $700^{\circ}C$, the main films growth direction was changed to be [200]. Two distinct growth behaviors were observed from the Arhenius plots. In addition to deposition of THe TiO2 thin films on Si(100) substrates, patterning of TiO2 thin films was also performed at grown temperature in the range of 300-50$0^{\circ}C$ by MOCVD onto the Si(100) substrates of which surface was modified by organic thin film template. The organic thin film of SAm is obtained by the $\mu$CP method. Alpha-step profile and optical microscope images showed that the boundaries between SAMs areas and selectively deposited TiO2 thin film areas are very definite and sharp. Capacitance - Voltage measurements made on TiO2 films gave a dielectric constant of 29, suggesting a possibility of electronic material applications.

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Study on the Characteristics of Gas Hydrate Layers Distributed in the Southern Ulleung Basin, the East Sea (동해 울릉분지 남부해역에 분포하는 가스 하이드레이트층의 특성 연구)

  • Huh Sik;Yoo Hai-Soo;Kim Han-Joon;Han Sang-Joon;Lee Yong-Kuk
    • The Korean Journal of Petroleum Geology
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    • v.10 no.1_2 s.11
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    • pp.18-22
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    • 2004
  • To identify and interpret the distribution and the characteristics of the gas hydrate layers in the Ulleung Basin, we have surveyed and gathered the multi-channel seismic data, Chirp sub-bottom profiler, SeaBeam and 12 m piston core samples since 1996. In previous works, high-resolution seismic profiles showed acoustic anomalies such as acoustic void, acoustic turbidity and pock mark which indicate the presence of gas-charged sediments. The patterns of horizontal degassing cracks originated from free methane expansion is the strong indicator of shallow gas-charged sediments in the core samples. The observation of submarine slides and slumps from destabilizing the sediments in the southern part of the Ulleung Basin may also point out that the gas had been released from gas hydrate dissociation during lowstand of sea level. The multi-channel seismic data show BSR, blanking and phase reversal. The gas hydrate layers above which large-scale shallow gases are distributed exist at the depth of about 200 m from the sea-floor with water depth of 2,100 m. From the interpretation of seismic sections in the southern Ulleung Basin, gas hydrate layers occur in the Pleistocene-Holocene sediments. These gas-charged sediments, acoustic anomalies and BSR may be all related to the existence of gas hydrate layers in the study area.

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Spectroscopic Comparison of Photo-oxidation of Outside and Inside of Hair by UVB Irradiation (자외선B 조사에 의한 모발 외부와 내부의 광산화에 관한 분광학적 비교)

  • Ha, Byung-Jo
    • Applied Chemistry for Engineering
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    • v.31 no.2
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    • pp.220-225
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    • 2020
  • Hair is made of proteins containing various amino acids. Ultraviolet (UV) radiation is believed to be responsible for the most damaging effects of sunlight, and also plays an important role in hair aging. The purpose of this study was to investigate the changes in morphological and chemical structures after ultraviolet B (UVB) irradiation of human hair. The UVB-irradiated hair showed characteristic morphological and structural changes, compared to those of the normal hair. The result from a scanning electron microscope (SEM) equipped with an energy dispersive X-ray diffractometer (EDX) showed that the scale of UV-irradiated hair appeared to be rough and the amount of oxygen element was higher than that of the normal hair. Fluorescence and three dimensional (3D) topographical images were obtained by a confocal laser scanning microscope (CLSM). In 3D images, the green emission intensity of normal hair was much higher than that of fluorescing UVB-irradiated hair. The intensity of green emission reflects the intrinsic fluorescence of hair protein. Also, a fluorescent imaging method using fluorescamine reagent was used to identify the free amino groups resulting from a peptide bond breakage in UVB-irradiated hair. Strong blue fluorescence of UVB-irradiated hair, which indicates a very high level of amino groups, was observed by CLSM. Therefore, the fluorescamine as an extrinsic fluorescence could provide a useful tool to identify the peptide bond breakage in UVB-irradiated hair. Infrared image mapping was also employed to assess the cross-sections of normal and UVB-irradiated specimens to examine the oxidation of disulfide bonds. The degree of peak areas with strong absorbance for the disulfide mono-oxide was spread from the outside to the inside of hair. The spectroscopic techniques used alone, or in combination, launch new possibilities in the field of hair cosmetics.

A Study on Causes of Franchisee's Conflict in Distribution Channel of small and middle sized Franchise Industry (중소형 프랜차이즈 유통시스템에서 가맹점의 갈등에 관한 질적 연구 - 토대이론 접근법을 활용하여-)

  • Jeon, Ta-sik
    • Journal of Distribution Science
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    • v.4 no.2
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    • pp.21-40
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    • 2006
  • Small and middle sized Franchise system channels experience conflicts because of constant interaction between franchiser and franchisee. However, it is rarely that attempt has been made to identify causes of conflicts in distribution of franchise industry. The purpose of this study was to explore cause of conflicts from the franchisee. For the study, data were collected from the owner or the shop-manager with a contractor in franchise systems. By means of in-depth interviews with multiple informants, their statement was analyzed qualitatively. From analysis of the resulting data, the causes of conflicts were associated with two broad sets, attitudinal and structural differences between franchisers and franchisees. First, attitudinal sources of conflict were identified as perception of subordinated relationships between channel members, delayed announcement on order changes, difficulties in communication by doing irresponsible behavior, different expectations between channel members in market territory and lack of consistent-supporting. Second, structural sources of conflict involved unilateral decision on interior, payment method, unreasonable delivery issue, treat franchisee with discrimination by the sales, in controlling against free management. There are limitations on generalization due to the results based on interview, but this study will be a useful exploratory step before designing a large scale survey.

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Evaluation of Quality Properties of Gamma-irradiated Freeze-dried Fruits (감마선 조사에 따른 동결건조과일의 품질 특성 평가)

  • Choi, Soo-Jeong;Yoon, Young-Min;Han, In-Jun;Kim, Jae-Kyung;Park, Jong-Heum;Lee, Ju-Woon;Lyu, Eun-Soon;Yook, Hong-Sun;Kim, Jae-Hun;Song, Beom-Seok
    • Journal of Radiation Industry
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    • v.6 no.4
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    • pp.299-304
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    • 2012
  • The quality properties of freeze-dried apples, pears, strawberries and pineapples gamma-irradiated at 0, 1, 2, 3, 4, and 5 kGy were evaluated to develop germ-free products for immuno-compromised patients. The initial count of total aerobic bacteria in non-irradiated apples, pears, strawberries and pineapple was 2.5, 3.1, 2.6, and $3.2{\log}\;CFU{\cdot}g^{-1}$, respectively. Microorganisms were not observed in apples after 1 kGy, in pears and strawberries after 4 kGy, and in pineapples at 5 kGy within a detection limit of $10{\log}\;CFU{\cdot}g^{-1}$. In addition, the sterilization of each sample was confirmed at the same dose. The score for the overall acceptance of freeze-dried fruit irradiated at a sterilization dose was 5.5 for apples, 4.1 for pineapples, and 4.0 for the other fruits, whereas that of non-irradiated control sample was 5.6 for apples, 5.2 for pears, and 5.8 for strawberries and pineapples with a 7-point scale. As a result, gamma irradiation of 1 kGy for apples, 4 kGy for strawberries and pears, and 5 kGy for pineapples is sufficient to sterilize each freeze-dried fruit with acceptable sensory properties.