• Journal of Korean Society of Forest Science
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• v.85 no.3
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• pp.396-408
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• 1996

The purposes of this study were to standardise the forest working system to design the intensity of working system in felling operation of the thinning forest in our country as well as to contrive the improvement of working method and the increase of productivity. For the purpose of investigating these, element working was classified by felling operation in softwood thinning forest, and a pulse rate were measured and analyzed. The results were as follow : 1. From the analysis of the pulse frequence measurment, the average pulse showed 108 pulse per minute for worker A in the total of pure working time, 130 pulse per minutes for worker B, 119 pulse per minute for worker C and 125 pulse per minute for worker D, respectively. 2. From the results of the pulse frequence analysis according to element working classification, the highest pulse frequence represented 115 pulse per minute for worker A in the circumference, 131 pulse per minute for worker B in the movement, 122 pulse per minute for worker C in the limbing operation and 128 pulse per minute for work D in hang-up. 3. If the original pulse frequence was 100% for workers, the working intensity showed as follow : worker A was 160%(original pulse frequence was 61=100%) for the total of the working intensity and 188% for the circumference among element working. Worker B was 220%(original pulse frequence was 57=100%) for the total of the working intensity and 229 for movement among element working. Worker C was 159%(original pulse frequence was 73=100%) for the total of the working intensity and 168% for limbing operation among the element working. Worker D was 156%(original pulse frequence was 70=100%) for the total of working intensity and 182% for hang-up among element working. 4. At the limit point of Labor performance rating, showing the total of working intensity, overtime pulse rate per minute was 30 for worker A, 207 for worker B, 14 for worker C and 67 for worker D. Worker B was highest in working intensity, and got physically a big load.

• Journal of Life Science
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• v.28 no.3
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• pp.275-283
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• 2018

Human fibroblast growth factor (FGF) has the potential to be a commercially important therapeutic or cosmeceutical agent due to its ability to generate tissue and heal wounds. Granting permeability into skin tissues increases the therapeutic effects of FGF. Thus, several researchers have attempted the fusion of FGF conjugates with protein transduction domains (PTDs) to investigate the transduction ability and therapeutic effects of FGF. Less is known, however, about whether the location of PTD fused to the N- or C-terminus of FGF proteins has a significant impact on the folding and stability in Escherichia coli, and eventually, on transduction. Here, we report cloning of human basic fibroblast growth factor (FGF2) as a control and FGF2 with PTD fused to the N- or C-terminal ends of FGF proteins by an overlap extension PCR. We performed expression, verified expression properties of recombinant FGF2 without or with PTD fused to the N-terminus and the C-terminus, and investigated transduction ability into tissue by treating the dorsal skin of mice subjects. As a result, FGF2 and FGF2-PTD (fused to C-terminus) fusion protein were expressed as soluble forms suitable for straight-forward purification, unlike insoluble PTD-FGF2 (fused to N-terminus), but only FGF2-PTD fusion protein could transduce into the dorsal skin tissue of the mice subjects. Our results suggest that FGF2 with PTD fused to the C-terminus is more efficient than other options in terms of expression, purification, and delivery into skin tissue, as it does not require labor-intensive, costly, and time-consuming methods.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.1
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• pp.58-71
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• 2015

Objectives: The aims of this study were to investigate the classification system of chemical substances in the Occupational Safety and Health Act(OSHA) and Chemical Substances Control Act(CSCA) and to compare several health indices (i.e., Time Weighted Average (TWA), Lethal Dose ($LD_{50}$), and Lethal Concentration ($LC_{50}$) of chemical substances by categories in each law. Methods: The chemicals regulated by each law were classified by the specific categories provided in the respective law; seven categories for OSHA (chemicals with OELs, chemicals prohibited from manufacturing, etc., chemicals requiring approval, chemicals kept below permissible limits, chemicals requiring workplace monitoring, chemicals requiring special management, and chemicals requiring special heath diagnosis) and five categories from the CSCA(poisonous substances, permitted substances, restricted substances, prohibited substances, and substances requiring preparation for accidents). Information on physicochemical properties, health indices including CMR characteristics, $LD_{50}$ and $LD_{50}$ were searched from the homepages of the Korean Occupational and Safety Agency and the National Institute of Environmental Research, etc. Statistical analysis was conducted for comparison between TWA and health index for each category. Results: The number of chemicals based on CAS numbers was different from the numbers of series of chemicals listed in each law because of repeat listings due to different names (e.g., glycol monoethylether vs. 2-ethoxy ethanol) and grouping of different chemicals under the same serial number(i.e., five different benzidine-related chemicals were categorized under one serial number(06-4-13) as prohibited substances under the CSCA). A total of 722 chemicals and 995 chemicals were listed at the OSHA and its sub-regulations and CSCA and its sub-regulations, respectively. Among these, 36.8% based on OSHA chemicals and 26.7% based on CSCA chemicals were regulated simultaneously through both laws. The correlation coefficients between TWA and $LC_{50}$ and between TWA and $LD_{50}$, were 0.641 and 0.506, respectively. The geometric mean values of TWA calculated by each category in both laws have no tendency according to category. The patterns of cumulative graph for TWA, $LD_{50}$, $LC_{50}$ were similar to the chemicals regulated by OHSA and CCSA, but their median values were lower for CCSA regulated chemicals than OSHA regulated chemicals. The GM of carcinogenic chemicals under the OSHA was significantly lower than non-CMR chemicals($2.21mg/m^3$ vs $5.69mg/m^3$, p=0.006), while there was no significant difference in CSCA chemicals($0.85mg/m^3$ vs $1.04mg/m^3$, p=0.448). $LC_{50}$ showed no significant difference between carcinogens, mutagens, reproductive toxic chemicals and non-CMR chemicals in both laws' regulated chemicals, while there was a difference between carcinogens and non-CMR chemicals in $LD_{50}$ of the CSCA. Conclusions: This study found that there was no specific tendency or significant difference in health indicessuch TWA, $LD_{50}$ and $LC_{50}$ in subcategories of chemicals as classified by the Ministry of Labor and Employment and the Ministry of Environment. Considering the background and the purpose of each law, collaboration for harmonization in chemical categorizing and regulation is necessary.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.1
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• pp.12-21
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• 1999

This study was carried out to improve the cultivation method of paddy rice when the application amount of nitrogen decreased. We investigated the growth and the yield of paddy rice, the changes of nutrients in the soil solution, soil and paddy rice. The results are as follows. The yield at the N4 plot(N $73kg\;ha^{-1}$) was higher than that of control(N $110kg\;ha^{-1}$). N1(N $55kg\;ha^{-1}$), N2(N $55kg\;ha^{-1}$), and N3(N $73kg\;ha^{-1}$). The number of panicle per square meter at the N4 plot was larger than that of control plot. The increase in yield at the N4 plot was due to increased number of panicle where planting density was two times higher compared to the control plot. The availability of nitrogen at the N4 plot also was two times higher than that of control plot. The pH in soil solution was around 7 and did not change largely. The $K^+$ concentration in soil solution at all plots decreased gradually. The $Ca^{2+}$ concentration in soil solutions increased gradually, and decreased at the later stage slightly. The P concentration in soil solution decreased gradually, increased after the heading stage, and then decreased due to decrease of soil temperature. Leaching of $Ca^{2+}$ was higher, while that of $K^+$ and P was lower compared to other ions. Total content of nutrients in soil after harvest decreased. Contents of total N, total P, and O.M. at the N4 plot were higher than those of the other plots. The content of total N and O.M. was correlated to yield. Contents of N, P and K in rice straw and grain at the N4 plot were the highest among all plots. In conclusion, to decrease N application amount in paddy rice cultivation as well as to maintain yield, planting density should be twice of control and the amount of application of N fertilizer should be two-third of control where N fertilizer should be applied mainly at 20 and 10 day before heading.

• Economic and Environmental Geology
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• v.38 no.6 s.175
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• pp.717-729
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• 2005

Peak cooling load of large buildings is generally greater than their peak heating load. Internal and solar heat gains are used fur selection of adquate equipment in large building in cold winter climate like Canada and even Korea. The cost of geothermal heat exchanger to meet the cooling loads can increase the initial cost of ground source heat pump system to the extend less costly conventional system often chosen. Thermal ice storage system has been used for many years in Korea to reduce chiller capacity and shift Peak electrical time and demand. A distribution system designed to take advantage of heat extracted from the ice, and use of geothermal loop (geothermal heat exchanger) to heat as an alternate heat source and sink is well known to provide many benifits. The use of thermal energy storage (TES) reduces the heat pump capacity and peak cooling load needed in large building by as much as 40 to $60\%$ with less mechanical equipment and less space for mechanical room. Additionally TES can reduce the size and cost of the geothermal loop by 1/3 to 1/4 compared to ground coupled heat pump system that is designed to meet the peak heating and cooling load and also can eliminate difficuties of geothermal loop installation such as space requirements and thermal conditions of soil and rock at the urban area.

• Journal of the Korean Geographical Society
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• v.30 no.2
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• pp.146-168
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• 1995

problems involved in defining and identifying it. However, data on ownership of business establishments may be useful and one of the best alternatives for this empirical research because of use of limited information about control This study examines the spatial patterns of external control in the Korean manufacturing activities between 1986 and 1992. Using the data on ownership iinkages of multilocational firms between 15 administrative areas, it was possible to construct a matrix of organizational control in terms of the number of establishments. The control matrix was disaggregated by three types of manufacturing industries according to the capital and labor requirements of production processes used in. On the basis of the disaggregated control matrix, a series of measures were calculated for investigating the magnitude and direction of control as well as the external dependency. In the past decades Korean industrialization development has risen at a rapid pace, deepening integration into the world economy, together with the continuing growth of the large industrial firms. The expanded scale of large firms led to a spatial separation of production from control, Increasing branch plants in the nation. But recent important changes have occurred in the spatial organization of production by technological development, increasing international competition, and changing local labor markets. These changes have forced firms to reorganize their production structures, resulting in changes of the organizational structures in certain industries and regions. In this context the empirical analysis revealed the following principal trends. In general term, the geography of corporate control in Korea is marked by a twofold pattern of concentration and dispersion. The dominance of Seoul as a major command and control center has been evident over the period, though its overall share of allexternally controlled establishments has decreased from 88% to 79%. And the substantial amount of external control from Seoul has concentrated to the Kyongki and Southeast regions which are well-developed industrial areas. But Seoul's corporate ownership links tend to streteh across the country to the less-developed regions, most of which have shown a significant increase of external dependency during the period 1986-1992. At the same time, a geographic dispersion of corporate control is taking place as Kyongki province and Pusan are developing as new increasingly important command and control reaions. Though these two resions contain a number of branch plants controlled from other locations, they may be increasingly attractive as a headquarters location with increasing locally owned establishments. The geographical patterns of external control observable in each of three types of manufacturing industries were examined in order to distinguish the changing spatial structures of organizational control with respect to the characteristics of the production processes. Labor intensive manufacturing with unskilled iabor experienced the strongest external pressure from foreign competition and a lack of low cost labor. The high pressure expected not only to disinte-grate the production process but also led to location of production facilities in areas of cheap labor. The linkages of control between Seoul and the less-developed regions have slightly increased, while the external dependency of the industrialized regions might be reduced from the tendency of organizational disintegration. Capita1 intensive manufacturing operates under high entry and exit barriers due to capital intensity. The need to increase scale economies ied to an even stronger economic and spatial oncentration of control. The strong geographical oncentration of control might be influenced by orporate and organizational scale economies rather than by locational advantages. Other sectors experience with respect to branch plants of multilocational firms. The policy implications of the increase of external dependency in less-developed regions may be negative because of the very share of unskilled workers and lack of autonomy in decision making. The strong growth of the national economy and a scarcity of labor in core areas have been important factors in this regional decentralization of industries to less-developed regions. But the rather gloomy prospects of the economic growth in the near future could prevent the further industrialization of less-developed areas. A major rethinking of regional policy would have to take place towards a need for a regional policy actively favoring indigenous establishments.

• KDI Journal of Economic Policy
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• v.13 no.1
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• pp.115-134
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• 1991

The role of pension plans in the macroeconomy has been a subject of much interest for some years. It has come to be recognized that pension plans may alter basic macroeconomic behavior patterns. The net effects on both savings and labor supply are thus matters for speculation. The aim of the present paper is to provide quantitative results which may be helpful in attaching orders of magnitude to some of the possible effects. We are not concerned with the providing empirical evidence relating to actual behavior, but rather with deriving the macroeconomic implications for a alternative possibilities. The pension plan interacts with the economy and the population in a number of ways. Demographic variables may thus affect both the economic burden of a national pension plan and the ability of the economy to sustain the burden. The tax transfer process associated with the pension plan may have implications for national patterns of saving and consumption. The existence of a pension plan may have implications also for the size of the labor force, inasmuch as labor force participation rates may be affected. Changes in technology and the associated changes in average productivity levels bear directly on the size of the national income, and hence on the pension contribution base. The vehicle for the analysis is a hypothetical but broadly realistic simulation model of an economic- demographic system into which is inserted a national pension plan. All income, expenditure, and related aggregates are in real terms. The economy is basically neoclassical; full employment is assumed, output is generated by a Cobb-Douglas production process, and factors receive their marginal products. The model was designed for use in computer simulation experiments. The simulation results suggest a number of general conclusions. These may be summarized as follows; - The introduction of a national pension plan (funded system) tends to increase the rate of economic growth until cost exceeds revenue. - A scheme with full wage indexing is more expensive than one in which pensions are merely price indexed. - The rate of technical progress is not a critical element in determining the economic burden of the pension scheme. - Raising the rate of benefits affects its economic burden, and raising the age of eligibility may decrease the burden substantially. - The level of fertility is an element in determining the long-run burden. A sustained low fertility rate increases the proportion of the aged in total population and increases the burden of the pension plan. High fertility has inverse effects.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.12 s.148
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• pp.1562-1570
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• 2005

The purpose of this thesis is to find the effective way of practical education in the fashion related department in order to supply the appropriate experts to the Korean apparel manufacturers located in Dalian, China. The interviews were made twice from $25^{th}$ of Feb. to $15^{th}$ of Mar. 2005 and from $28^{th}$ of July to 31st of July 2005 through the method ot a direct interview with the CEOs of the 7 representative apparel manufactures. The results of the interviews were as following. Seven companies$(100\%)$ participated in the survey all complained of insufficient workers. Also the companies were having difficulties at finding appropriate workers who can handle designing, management, and circulation, because specialists who are fluent in Korean and Chinese are very rare. Moreover, Korean apparel manufacturers are now taking a step further to launch a high quality fashion brand, getting out of the simple hand work depending on low wage or low-tech(6 companies $85.7\%$). Thus, well-educated fashion specialists(intermediate manager) are required on the part of Korean clothing companies or apparel manufacturers in China. It is expected the intermediate managers and the specialists who are capable of launching a new brand will be urgently needed. Therefore, appropriate educations in Korea would be essential to minimize the problems the Korean fashion specialists might face in China. 1 would like to present three suggestions. 1. The highly educated Korean fashion specialists on apparel industry will be a solution both to the high jobless status in our country and to the deficiency in human resources of Korean apparel manufacturers in Dalian. 2. The students in the college should learn how to write down the working chart and matching chart in practical conditions. Taking an intern-ship in working factories in China during a certain period of time will be helpful. 3. The experts should be trained with emphasis on the quality, design, and value of the brand. This study will be used as a base for Koreans who work in fashion related department to enter the Chinese fashion market having a great potential.

• Korean Journal of Food Science and Technology
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• v.42 no.3
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• pp.355-360
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• 2010

Vibrio parahaemolyticus (V. parahaemolyticus), which is commonly found in raw seafood, causes gastroenteritis in humans. Rapid and effective methods have been developed as culture methods require up to 5-7 days. In this study, real-time PCR was compared with the standard culture method for detecting V. parahaemolyticus in seafood and radish sprout samples. Five hundred grams of the samples were artificially contaminated with V. parahaemolyticus then divided into 20 samples. The samples were incubated in alkaline peptone water and then streaked onto thiosulfate-citrate-bile saltssucrose agar. Biochemical tests for suspicious colonies were performed using the API 20NE strip. In parallel, real-time PCR was performed targeting the toxR gene using the enrichment broth. The real-time PCR was sensitive in discriminating V. parahaemolyticus from other foodborne pathogens. The detection limit of the real-time PCR was $10^3\;CFU/mL$ in phosphate-buffered saline. Although the real-time PCR detected more positive samples (76 out of 180, 42%) than the culture method (66 out of 180, 37%), there was no significant statistical difference (p>0.05) between the two methods. In conclusion, real-time PCR assays could be an alternative to the standard culture method for detecting V. parahaemolyticus in seafood and radish sprouts, which has many advantages in terms of detection time, labor, and sensitivity.

• Korean journal of food and cookery science
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• v.18 no.6
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• pp.692-697
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• 2002

The purpose of this study is to investigate the characteristics of the doughs and noodles cooked with the pea starch-wheat composite flour which was substituted with 20% and 30% of pea starch for the flour by the mechanical and sensory evaluation. Wheat dough had the most cohesive property among various composite non.(p＜0.05) There was no significant differences in weight gain after cooking among various noodles. The more the pea starch was subsituted, the lighter the color was shown by increasing L value. It was also noted that the b value was decreased significantly. While pea starch noodle were more transparent in appearance and less smooth in the texture, corn starch-wheat composite flour noodle was sorter in the texture significantly. There was no significant difference on the hardness between wheat and pea stach composite flour noodles. There were also no significant differences in stickiness, chewiness and overall acceptability among various noodles. Considering mechanical and sensory results, the composite flour with 20% substitution of pea starch for flour was more suitable for the production of the noodle than those of 30% substitution of pea starch.