• Title/Summary/Keyword: Industry concentration

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A Study on Concentration and Centralization of Tonnage in Korean Shipping(A Comparative Study with Egypt)

  • Kim, Hyun-Deok;Ahn, Ki-Myung;Shin, Yong-John
    • Journal of Navigation and Port Research
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    • v.28 no.2
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    • pp.121-127
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    • 2004
  • The shipping industry can be explained by a growing process of concentration and centralization of tonnage. A few largest shipping company control a great deal of shipping tonnage in the total tonnage through the process of concentration and centralization of tonnage in shipping over time. It confirms that a decreasing number of operators take an increasing quantity of tonnage in the total tonnage. Thus, the extremely dualistic structure (extremely unequal distribution of tonnage) are shown not only in the shipping industry in a given country but also in liner shipping in the world In this paper, the two countries, that is, Korea and Egypt, are compared considering the absolute size of tonnage and shipping policy in tenn., of concentration and centralization of tonnage in shipping. In order to measure the degree of concentration of tonnage in shipping, the quantitative measurements; the Lorenz curve and Gini coefficient are introduced. But it should be supplemented with the qualitative measures of tonnage in a given country.

Preparation of Cation-exchange Resin from Lignin

  • Kamelt S.
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.36 no.5 s.108
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    • pp.78-84
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    • 2004
  • Lignin precipitated from black liquor of soda pulping of bagasse was used to prepare cation-exchange resin. The effect of sulfuric acid treatment, concentration of phenol and formaldehyde on the properties of the prepared cation-exchange resin was investigated. It was found that sulfonated resinified phenolated lignin gave a resin with an ion-exchange capacity higher than that of resin, which resulted from sulfonation of resinified lignin at zero phenol concentration. Infrared spectroscopy of the prepared ion-exchange resin shows anew bands at 1060, 1160, 1280 and $1330\;cm^{-1}$ which indicated to the presence of $SO_{3}$.

Analyzing the Relationship between Market Concentration and Performance in Global Pay TV Markets for the Media Industry Regulation and Policy (해외유료방송의 시장집중과 시장성과 간의 관계분석을 통한 미디어산업 규제 및 정책 방향)

  • Lee, Chi-Hyung;Lee, Bong-Gyou
    • Journal of Internet Computing and Services
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    • v.12 no.4
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    • pp.51-59
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    • 2011
  • The purpose of this study is to provide relevant directions of media industry regulation and policy by analyzing the relationship between market concentration and performance in global pay TV markets. The market concentration has long been regulated in the media industry under the belief that it harms market efficiency and cultural diversity. As the global media market is undergoing significant chance accelerated by the advance of technology, it is necessary to examine the feasibility of this long myth. The data are collected from global 17 pay TV markets and analyzed to see whether the highly concentrated markets by a single player result in higher price and slower service penetration. The result indicates that the price is not escalated and the penetration is not limited even in the markets where a dominant player takes high market share. It implies that more diverse factors other than the market concentration affect the market performance and that maintaining strict regulation of the market concentration is likely to have negative effect on technology innovation.

A study on the urinary metabolites of styrene exposed workers (직업적으로 스티렌에 노출된 근로자의 뇨중 대사산물에 관한 연구)

  • 오세욱;원정일
    • Journal of environmental and Sanitary engineering
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    • v.11 no.3
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    • pp.1-7
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    • 1996
  • Mandelic acid is the major metabolite and phenylglyoxylic acid is the minor metabolite of styrene in human. This study was conducted to investigate the correlation between exposure concentrations of styrene and concentration of the metabolites in urine The concentrations of metabolites in urine and exposure concentrations were measured in 60 workers who were occupationally exposed to styrene in FRP industry as well as paint industry and musical instrument manufacturing industry and the concentrations of metabolites in urine ware measured in 90 workers not occupationally exposed to styrene for review the background level in the unexposed population. The results obtained were as follows; 1. The mean exposure concentration is 16.6 $\pm $12.2 ppm (range 0.4-49.9ppm) in the styrene exposed workers. 2. The concentration of mandelic acid in urine collected at the end of shift from worker exposed 8 hours to 50ppm of styrene, based on extrapolation from correlation equations was 578.5 mg/g creatinine and 176.8 mg/g creatinine for next morning urine, the concentration of phenylglyoxylic acid in urine collected at the end of shift was 291.1 mg/g creatinine, 177.9 mg/g creatinine in next morning urine. In the sum of mandelic acid and phenylglyoxylic acid in the urine 870.2 mg/g creatinine in urine sampled at the end of shift corresponds to an exposure of 50ppm of styrene and 366.0 mg/g creatinine for next morning sample corresponds to 50ppm. 3. The correlation of the degree of exposed with sum concentration of mandeliacid and phenylglyoxylic acid in the urine was better(r=0.079 for end of shift, r=0.78 for next morning) than the correlation with single determinant measurement in urine(r=0.75 for mandelic acid at end of shift, r=0.73 for mandelic acid at next morning, r=0.69 for phenylglyoxylic acid at end of shift, r=0.62 for phenylglyoxylic acid at next morning). The monitoring of sum concentration of mandelic acid and phenylglyoxylic acid in urine is a valuable indicator of time weighted average daily exposure ti styrene. And the exposure standard of urinary metabolites produced by styrene should be set, in distinction urine at the end of shift from urine at next morning.

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A Study on the Functionality in Natural Colorants

  • Song, Eun-Young;Ahn, In-Yong;Suh, Hwa-Jin;Kim, Mi-Jin;Park, Jin-Woo;Kwon, Oh-Oun
    • Proceedings of the Korean Society of Dyers and Finishers Conference
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    • 2012.03a
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    • pp.122-122
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    • 2012
  • The aims of this study were to examine the efficacy of phytochemical compounds of colorants as anti-oxidant agent. The bioactive properties of natural colorants were studied by total phenolic contents, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and anti-bacterial activity in Escherichial coli. The concentration ($IC_{50}$) of various extracts from colorants required to exert 50% reducing effect on DPPH radical were found to be 0.007-4 mg/ml. Especially, the gallnut (Schlectendalia Chinensis) displayed remarkable effect of DPPH as compared to positive control ascorbic acid. The total phenolic contents (TPC) and restraint of E coli. also analyzed. It was found that gallnut extracts effectively inhibited DPPH radical at a concentration below 0.01 mg/ml. Natural colorant extracts could be of good resources as anti-oxidant and anti-bacterial agents. The results suggest that our study may contribute to the development of natural and functional materials with potential application to reduce oxidative damage.

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A Trend Analysis of Market Structure in the Korean Daily Newspaper Industry (타일지수와 이동지표를 활용한 미디어 시장구조 분석 전국종합일간지 시장을 중심으로)

  • Oh, Jeongho
    • Korean journal of communication and information
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    • v.78
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    • pp.141-176
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    • 2016
  • This study investigates changes of market structure from 2001 to 2015 in the Korean daily newspaper industry using concentration and mobility measures. The main empirical results are as follows. First, the industry's total asset shows a U-shaped trend, despite the downward trend of the industry's total sales revenue. Second, the market concentration, measured in terms of assets, shows the trend of an inverted-U shape. The relatively small firms, measured in terms of assets, have on average gained in market share while the relatively large firm have lost. Third, market concentration, measured in terms of sales revenues, shows a U-shaped trend. the relatively small firms, measured in terms of sales revenues, have on average gained in market share while the relatively large firm have lost. My central argument has been that it is desirable to supplement traditional concentration measures with mobility statistics and trend analyses in investigating and regulating market structure.

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Effects of Strong Wind and Ozone on Localized Tree Decline in the Tanzawa Mountains of Japan

  • Suto, Hitoshi;Hattori, Yasuo;Tanaka, Nobukazu;Kohno, Yoshihisa
    • Asian Journal of Atmospheric Environment
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    • v.2 no.2
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    • pp.81-89
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    • 2008
  • The numerical simulation of wind and ozone ($O_3$) transport in mountainous regions was performed with a computational fluid dynamics technique. A dry deposition model for $O_3$ was designed to estimate $O_3$ deposition in complex terrain, and the qualitative validity of the predicted $O_3$ concentration field was confirmed by comparison with observed data collected with passive samplers. The simulation revealed that wind velocity increases around ridge lines and peaks of mountains. The areas with strong wind corresponded well with the sites of tree decline at high altitudes, suggesting that it is an important factor in the localization of tree/forest decline. On the other hand, there is no direct relationship between forest decline and $O_3$ concentration. The $O_3$ concentration, however, tends to increase as wind velocity becomes higher, thus the $O_3$ concentration itself may be a potential secondary factor in the localized decline phenomena. While the diffusion flux of $O_3$ is not related to localized tree decline, the pattern of advection flux is related to those of high wind velocity and localized tree decline. These results suggest that strong wind with large advection flux of $O_3$ may play a key role in the promotion of tree/forest decline at high mountain ridges and peaks.

Development of high-resolution atmosphere ocean coupled model and global warming projection with Earth Simulator -A whole research plan and result in FY2002-

  • Maruyama, Koki
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 2003.08a
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    • pp.18-27
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    • 2003
  • The goal of the UN Framework Convention on Climate Change (UNFCCC) is to stabilize atmospheric CO2 concentration for preventing global warming in future. However, there are many unknown factors regarding stabilization of CO2 concentration. What level of concentration should be appropriate to prevent global warming? When should we stop the increase of CO2 concentration\ulcorner What kind of countermeasures of reducing CO2 emission will be available for CO2 stabilization?(omitted)

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Effects of Alkali Concentration on Fiber Characteristics of SwBKP during Alkali Treatment in Cosolvent System (알칼리 공용매 팽윤처리 시 알칼리 농도가 SwBKP 섬유 특성에 미치는 영향)

  • Seo, Ji-Hye;Choi, Kyoung-Hwa;Cho, Byoung-Uk
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.48 no.3
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    • pp.37-43
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    • 2016
  • Various mechanical and chemical pretreatment methods including alkali treatment, pre-beating, enzyme treatment and oxidation treatment have been used to reduce the production energy of the microfibrillated cellulose (MFC). Among them, alkali swelling can be helpful to reduce the energy consumption because the internal bonding between fibrils could be weakened. In this study, dimethyl sulfoxide (DMSO) was used as a cosolvent to improve alkali pretreatment efficiency and the effects of NaOH concentration during NaOH-DMSO swelling on changes in fiber characteristics of softwood bleached kraft pulp (SwBKP) were elucidated. For alkali treatment in H2O-DMSO solvents, fiber length were decreased with increasing NaOH concentration while fiber width, curl and WRV were increased. WRV began to increase at 8% NaOH solution. In addition, above 8% concentration of NaOH, crystalline structure of pulp fibers converted from cellulose II to cellulose III by DMSO cosolvent. Comparing the previous results with this study, it was shown that DMSO cosolvent could promote swelling of pulp fibers and thus reduce NaOH concentration for the maximum swelling of fibers.

Manufacture of Low Density Paper by Cationic Fatty Acid Amine Bulky Promotor Treatment (3) - Effect of Pulp Beating Degree and Bulky Promotor Concentration - (양이온성 지방산아민 벌키화제를 이용한 저밀도 종이 제조 (3) - 펄프 고해도 및 벌키화제 처리 농도에 따른 영향 -)

  • Nam, Yun-Seok;Choi, Kyoung-Hwa;Jin, Hai-Lan;Cho, Jun-Hyung
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.48 no.1
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    • pp.111-118
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    • 2016
  • The effects of pulp beating degree and bulky promotor concentration on the properties of handsheet including a bulk and strength have been investigated during manufacturing of low density paper (high bulk paper) with cationic fatty acid bulky promotor. It was found that paper bulk increased with increasing cationic fatty acid bulky agent concentration, while tensile strength decreased. On the other hand the opacity of handseets also increased with increasing cationic fatty acid bulky agent concentration, while brightness decreased slightly. With increasing pulp beating degree, paper bulk as well as tensile strength increased, while opacity decreased. Brightness did not show a significant difference with increasing pulp beating degree. The highest bulk and strength values were observed when 1.5% (SwBKP) and 2% (HwBKP) of bulky promotor was treated into the 450 mL CSF pulp slurry.