• Title/Summary/Keyword: Dispersion factor

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A Study of the Diagnosis of Downtown Deterioration in Busan (부산시 도심 노후화 진단에 관한 연구)

  • Kwon, Il-Hwa;Nam, Kwang-Woo
    • Journal of the Korean Association of Geographic Information Studies
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    • v.16 no.4
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    • pp.39-53
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    • 2013
  • Although the efficient formation of urban space structure is a key factor in energy saving and environmentally-friendly aspect, the maintenance of the center and sub-center of the city that are key factors has been becoming increasingly difficult due to the variability and complexity of urban activities. In the case of Busan, amid the expansion of urban scale due to rapid economic development and overpopulation, systematic approaches to professional diagnosis and maintenance have been significantly insufficient - other than the city basic plan which has been conducted at an interval of 20 years. For the effective management of urban central area, systematic monitoring of the CBD through demand forecast and blight forecast at a city level must first be implemented. In order to fulfill this goal, this study is to figure out the current state of the CBD through the diagnosis on blight of the urban central area in the viewpoint of rehabilitation of the CBD and to propose the measures for practical utilization of the information about space for the further management of the central area of the city. For analysis, the study looks into the present state in terms of physical index, economic index, and social index. And then as a micro-approach by utilizing economic index, the study has thoroughly examined the economic blight of the Seomyun urban central area of Busan. The outcome of the analysis shows that in terms of population distribution and land utilization the area is in the stage of inefficient dispersion after having gone through the stage of suburbanization. It is expected that this study, as the material that proves the necessity of enhancing the function of the CBD, can propose the direction for the management of the urban center of Busan through blight prediction and management of the urban center and can provide the basic data for the long-term urban development that aims at the efficient strengthening of functions of the CBD.

High Alloying Degree of Carbon Supported Pt-Ru Alloy Nanoparticles Applying Anhydrous Ethanol as a Solvent

  • Choi, Kwang-Hyun;Lee, Kug-Seung;Jeon, Tae-Yeol;Park, Hee-Young;Jung, Nam-Gee;Chung, Young-Hoon;Sung, Yung-Eun
    • Journal of Electrochemical Science and Technology
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    • v.1 no.1
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    • pp.19-24
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    • 2010
  • Alloying degree is an important structural factor of PtRu catalysts for direct methanol fuel cells (DMFC). In this work, carbon supported PtRu catalysts were synthesized by reduction method using anhydrous ethanol as a solvent and $NaBH_4$ as a reducing agent. Using anhydrous ethanol as a solvent resulted in high alloying degree and good dispersion. The morphological structure and crystallanity of synthesized catalysts were characterized by X-ray diffraction (XRD), high resolution transmission electron microscope (HR-TEM). CO stripping and methanol oxidation reaction were measured. Due to high alloying degree catalyst prepared in anhydrous ethanol, exhibited low onset potential for methanol oxidation and negative peak shift of CO oxidation than commercial sample. Consequently, samples, applying ethanol as a solvent, exhibited not only enhanced CO oxidation, but also increased methanol oxidation reaction (MOR) activity compared with commercial PtRu/C (40 wt%, E-tek) and 40 wt% PtRu/C prepared in water solution.

Analysis on Organization Performance Based on Hospital Culture (기독병원과 일반병원의 조직문화 특성에 따른 조직성과 분석)

  • Kim, Woon-Shin;Nam, Eun-Woo
    • Korea Journal of Hospital Management
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    • v.4 no.2
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    • pp.242-265
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    • 1999
  • Our study attempt is to see organizational performance according to the differences between types of hospital cultures. To determine theoretical relationship between the organizational culture and the performance, we select two hospitals in Pusan which are different in the purposes and shapes of establishment. We surveyed their members on a questionnaire based on the type of the organizational culture of the two institutions, analyzed, and review its organizational effectiveness. For the survey with questionnaires, which had been preliminary studied to raise its validity, question forms were distributed to 528 persons in April, 1999 based on the self-responses and recollected within 48 hours. The recollection rate was high(89.96%) and the quantity of questionnaires used for our final analysis was 430(81.44%). The Cronbach Coefficient Alpha of the questionnaires was 0.742. Regarding statistical techniques for analysis of the written materials, dispersion analysis(ANOVA) was adapted to test the organizational effectiveness of the two hospitals having the different organizational cultures, and Pearson Correlation was applied to determine correlations was among all variables. T-test was performed to test organizational effectiveness based on the differences in the extent of sharing the culture, organizational committment and work satisfaction between the two health institutions. From our analysis, we obtain the following conclusions. First, concerning with organizational culture of the two hospital, one of which is a christian hospital and the other is a private foundation hospital, the former is conservative and human-oriented but the latter focuses on renovation and accomplishment. Second, the private establishment has a relatively higher organizational effectiveness that the religious hospital as a result of analyzing the extent of sharing culture, organizational committment and work satisfaction. Third, it has been found that the correlations between the extent of the sharing culture and the organizational committment, the extent and work satisfaction, and the committment and the satisfaction are respectively positive influencing organizational effectiveness, especially work satisfaction. Fourth, cultural factors by which the christian hospital is affected more positively including human relations among its members, belief, its idea of establishment, tradition, work responsibility, power, and wage. On the other hand, factors such as director's leadership, personnel management, wage, hospital regulations and department managers' management ability have been seen as negative influences in order. And fifth, for the private foundation hospital human relations among its members, wages, work responsibility, director's leadership and department managers' management ability were positive in their sequence while wages, personnel management, hospital regulations, welfare and department managers' management ability were considered as negative influences in order. As these results of this study, the higher extent of sharing organizational culture, the more increasing in both organization committment and work satisfaction, the higher the effectiveness. Although it was somewhat difficult to generalize the results whose subjects were the two hospitals only, it was obvious that organizational culture was an important influential factor of organizational effectiveness. It is questionable that the extent of sharing organizational culture, organizational committment and work satisfaction as variables affecting the effectiveness have their validity, but this study has its significance in that it provided an approaching to evaluate the organizational culture of individual hospitals making allowances for such variables related to the general activities in its hospital. We hope the results of the study could be useful for the managerial strategies of the institutions.

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Analysis of Siting Criteria of Overseas Geological Repository (II): Hydrogeology (국외 심지층 처분장 부지선정기준 분석 (II) : 수리지질)

  • Jung, Haeryong;Kim, Hyun-Joo;Cheong, Jae-Yeol;Lee, Eun Yong;Yoon, Jeong Hyoun
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.11 no.3
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    • pp.253-257
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    • 2013
  • Geology, hydrogeology, and geochemistry are the main technical siting factors of a geological repository for spent nuclear fuels. This paper evaluated the siting criteria of overseas geological repository with related to hydrogeologic properties, such as hydraulic conductivity, partitioning coefficient, dispersion coefficient, boundary condition, and water age. Each country establishes the siting criteria based on its important geological backgrounds and information, and social environment. For example, Sweden and Finland that have decided a crystalline rock as a host rock of a geological repository show different siting criteria for hydraulic conductivity. In Sweden, it is preferable to avoid area where the hydraulic conductivity on a deposition hole scale (~30m) exceeds $10^{-8}m/s$, whereas Finland does not decide any criterion for the hydraulic conductivity because of limited data for it. In addition, partitioning coefficients should be less than 10-1 of average value in Swedish crystalline bedrock. However, the area where shows 100 times less than average partitioning coefficients of radionuclides in crystalline rock should be avoided in Sweden. In German, the partitioning coefficients for the majority of the long-term-relevant radionuclides should be greater than or equal to $0.001m^3/kg$. Therefore, it is strongly required to collect much and exact information for the hydrogeologic properties in order to set up the siting criteria.

Evaluation of high power ultrasonic energy transmission characteristics of a liquid matching layer by using sonoluminescence (소노루미네센스를 이용한 액체정합층의 고출력 초음파에너지 전달특성 평가)

  • Kim, Jungsoon;Kim, Haeun;Son, Jinyoung;Kim, Moojoon
    • The Journal of the Acoustical Society of Korea
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    • v.40 no.5
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    • pp.408-416
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    • 2021
  • In the ultrasonic dispersion, in order to avoid direct contact of the radiation surface of ultrasonic transducers with a liquid sample, the liquid sample is separated by a glass container and it receives ultrasonic energy through an acoustic medium. The transmission efficiency of the ultrasonic energy in the multi-layered ultrasonic system is an important factor. In this study, we suggested a method that can improve the ultrasonic energy transfer efficiency by using a propylene glycol solution as a liquid matching layer in the multi-layered acoustic system. In this method, a propylene glycol solution was filled between the Langevin-type ultrasonic transducer and the luminol solution and the sonoluminescence phenomena in the luminol solution, which is caused by nonlinear effect of high power ultrasound radiated from the transducer, was examined by using a Photo Multiplier Tube (PMT). The transmission efficiency depending on the concentration of propylene glycol solution was observed, and we can see that as the concentration of the propylene glycol solution increased, the matching effect increased while the acoustic attenuation increased. It was confirmed that there is an optimal concentration compromised these two conflicting conditions, and the optimum concentration of the propylene glycol solution was determined experimentally.

The Analysis of Economic Contribution of Character Industry in China (산업연관분석에 의한 중국 캐릭터 산업의 경제적 효과 분석)

  • Zhang, Xin-Dan;Yao, Jin-Ge;Lee, Hyuck-Jin
    • The Journal of the Korea Contents Association
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    • v.21 no.9
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    • pp.125-135
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    • 2021
  • Due to the lack of national consensus on the importance and value of the character industry and the lack of recognition of value as a national strategic industry, the development of the character industry is experiencing great difficulties. The purpose of this study is to analyze the economic effects of character industry in China to help establish policies and strategies for the character industry in the future. To this end, this study utilized the China 2017 Industrial Association Table. The analysis results are as follows. China's character industry has a lower production inducement effect than other industries with a column total of 3.45514, and a row total of 1.30015. This shows that China's character industry is still being produced by small and medium-sized companies with a low equity ratio. Second, in the character industry, the index of the sensitivity of dispersion representing the forward linkage effect is 0.01426 and the impact factor is 0.03790, which are all less than 1. Therefore, it can be said to be the final demand manufacturing type.Third, in China character industry's income induction is 0.47690 and the production tax induction effect is -0.04912. It can be seen that the character industry has less income induction and tax burden generated every time the final demand increases by one unit in the entire industry than in other industries.Despite the quantitative growth of the character industry in China, the impact on other industries is low and it is not playing a role as an income-generating industry. Structural improvement is needed for the qualitative development of China's character industry.

Spatial Distribution Patterns of Oplismenus undulatifolius var. undulatifolius on Mt. Hanwoo in Korea (한우산에 분포하는 주름조개풀의 공간적 양상)

  • Huh, Man Kyu
    • Journal of Life Science
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    • v.28 no.11
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    • pp.1262-1267
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    • 2018
  • The patchiness of local environments within a habitat is assumed to be a primary factor affecting the spatial patterns of plants. In this study, a randomization procedure was developed to test the null hypothesis that only spatial association with patches determines the spatial patterns of plants. Oplismenus undulatifolius (Ard.) P. Beauv. var. undulatifolius is an herbaceous plant and a member of the genus Oplismenus in the family Poaceae. Oplismenus hirtellus subsp. undulatifolius occurs in temperate, subtropical, and tropical areas of the world. The spatial pattern of O. undulatifolius var. undulatifolius was analyzed using dispersion indices in different sizes of plots according to several patchiness indexes, population uniformity, or aggregation. Population densities (D) at Mt. Hanwoo varied from 0.453 to 4.375, with a mean of 2.387. The small and mid-sized plots ($2m{\times}2m$, $2m{\times}4m$, $4m{\times}4m$, $4m{\times}8m$, and $8m{\times}8m$) of O. undulatifolius var. undulatifolius were aggregated in the forest community. However, O. undulatifolius var. undulatifolius was uniformly distributed in three large plots ($8m{\times}16m$, $16m{\times}16m$, and $16m{\times}32m$). The greatest mean crowding ($M^*$) and patchiness index (PAI) showed positive values. Aggregation is mainly caused by environmental factors. Many plants on Mt. Hanwoo are being disturbed by climbers, which is preventing these plants from inhabiting their realized niches on Mt. Hanwoo.

Measurement of Bubble Size in Flotation Column using Image Analysis System (이미지 분석시스템을 이용한 부선컬럼에서 기포크기의 측정)

  • An, Ki-Seon;Jeon, Ho-Seok;Park, Chul-Hyun
    • Resources Recycling
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    • v.29 no.6
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    • pp.104-113
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    • 2020
  • Bubble size in froth flotation has long been recognized as a key factor which affects the bubble residence time, the bubble surface area flux (Sb) and the carrying rate (Cr). This paper presents method of bubble size measurement, relationship between operating variables and gas dispersion properties in flotation column. Using high speed camera and image analysis system, bubble size has been directly measured as a function of operating parameters (e.g., superficial gas rate (Jg), superficial wash water rate (Jw), frother concentration) in flotation column. Relationship compared to measured and estimated bubble size was obtained within error ranges of ±15~20% and mean bubble size was 0.718mm. From this system the empirical relationship to control the bubble size and distribution has been developed under operating conditions such as Jg of 0.65~1.3cm/s, Jw of 0.13~0.52cm/s and frother concentration of 60~200ppm. Surface tension and bubble size decreased as frother concentration increased. It seemed that critical coalescence concentration (CCC) of bubbles was 200ppm so that surface tension was the lowest (49.24mN/m) at frother concentration of 200ppm. Bubble size tend to increase when superficial gas rate (Jg) decreases and superficial wash water rate Jw and frother concentration increase. Gas holdup is proportional to superficial gas rate as well as frother concentration and superficial wash water rate (at the fixed superficial gas rate).

A Study on the Emulsifying Stability of W/O Type Sunscreen Cream by the Hansen Solubility Parameter (Hansen Solubility Parameter 를 통한 W/O 형 자외선차단 제형의 유화 안정성에 관한 연구)

  • Kim, Dong Hee;Lee, Jin Jae
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.47 no.4
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    • pp.273-280
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    • 2021
  • The water resistance is important factor for sunscreen formulations. Generally a sunscreen cream was formulated by a water-in-oil (W/O) emulsion. In the W/O emulsion system, silicone oils are added to improve the texture of formulations. Silicone oils have low compatibility with organic sunscreen agent, causing problems with the stability in emulsion. In this study, the compatibility between various oils in the W/O emulsion was derived numerically using Hansen solubility parameter (HSP) at first. HSP is represented a dispersion degree, a polarity, and a hydrgen bond in a composition. In this study, various emulsions were prepared according to the types of oils with different HSP values and then monitored by a viscosity and morphology according to the time and temperature. The HSP values of components and the experimental results have similar activities for the stability of emulsions. HSP made it easy to select oil with high compatibility. When the compatibility of the oil phase in the W/O emulsion was high, the viscosity change over time was small. The stability was improved under the freeze-thaw cycle (-15 ℃ ~ 45 ℃). In the future, if the composition of the ingredients is optimized through HSP, it is expected that it will be helpful in the development of W/O type sunscreen formulations that are excellent in use and stability.

Enhancement of Penetration by Using Mechenical Micro Needle in Textile Strain Sensor (텍스타일 스트레인 센서에 마이크로 니들을 이용한 전도성입자 침투력 향상)

  • Hayeong Yun;Wonjin Kim;Jooyong Kim
    • Science of Emotion and Sensibility
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    • v.25 no.4
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    • pp.45-52
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    • 2022
  • Recently, interest in and demand for sensors that recognize physical activity and their products are increasing. In particular, the development of wearable materials that are flexible, stretchable, and able to detect the user's biological signals is drawing attention. In this study, an experiment was conducted to improve the dip-coating efficiency of a single-walled carbon nanotube dispersion solution after fine holes were made in a hydrophobic material with a micro needle. In this study, dip-coating was performed with a material that was not penetrated, and comparative analysis was performed. The electrical conductivity of the sensor was measured when the sensor was stretched using a strain universal testing machine (Dacell Co. Ltd., Seoul, Korea) and a multimeter (Keysight Technologies, Santa Rosa, CA, USA) was used to measure resistance. It was found that the electrical conductivity of a sensor that was subjected to needling was at least 16 times better than that of a sensor that was not. In addition, the gauge factor was excellent, relative to the initial resistance of the sensor, so good performance as a sensor could be confirmed. Here, the dip-coating efficiency of hydrophobic materials, which have superior physical properties to hydrophilic materials but are not suitable due to their high surface tension, can be adopted to more effectively detect body movements and manufacture sensors with excellent durability and usability.