• The Korean Journal of Malacology
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• v.19 no.1
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• pp.33-40
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• 2003

To obtain the basic information on culture conditions for the larvae of Saxidomus purpuratus, experiments were conducted on the population from southern coast for (1) the success in fertilization and development from artificial fertilization among different months of a year, (2) the viability of sperms after exposure to seawater, (3) and the effects of temperature, salinity, and food organism on the survival and growth of larvae. Gametes obtained from dissection showed high rate of fertilization at all months. But the rate of development was higher only May-July. Developmental success seemed to be related with the quality of eggs at the time of fertilization. Developmental times for 2-cell, 4-cell, 8-cell, blastula, trochophore larva, and veliger larva at 20$^{\circ}C$ were 1.5, 2, 4, 18, 24, and 32 hr, respectively. Sperms could survive for more than 8 hr, however, actively swimming sperms could be found within 1 hr after exposure to seawater. It is recommended that sperms should be used for fertilization as soon as possible when they are exposed to seawater. At temperature of 35$^{\circ}C$, all the larvae died during 48 hr. Larval survival decreased when salinity was either lower than 20 psu or higher than 40 psu, and was 0% when salinity was 10 psu. Optimal range of temperature and salinity for rearing larvae of S. purpuratus were 20-25$^{\circ}C$ and 20-40 psu, respectively. Larvae grew from 111.5 to 235.3 ${\mu}$m during 21 days. Larvae fed mixed diets grew faster than unialgal diets. The fastest growth was observed when larvae were fed on the mixture of Isochrysis galbana and Nannochloris oculata.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.4
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• pp.313-326
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• 2023

Owing to adverse weather conditions, there is a heightened focus on actively researching the regulation of the sowing date in field crop cultivation. Soybean, a prominent field crop with extensive acreage and production, is a photophilic and thermophilic crop characterized by short-day photoperiodism. Identifying the optimal sowing time is crucial for mitigating the effects of severe weather conditions on soybean yield. Precise control over the timing of soybean sowing is the key to minimizing yield reduction due to unfavorable weather conditions. Temperature, photoperiod, and their interplay are the most significant factors influencing soybean cultivation among various weather factors. We conducted an experiment using three Korean soybean cultivars with varied maturities (Hwangkeumol: early maturing and Daewonkong and Pungsannamulkong: late maturing) in 2013 and 2014. Our investigation covered aspects of soybean growth, development, yield components, isoflavones, and visual seed quality. Across all three varieties, isoflavone levels increased with later sowing dates, while other measured components exhibited significant variations based on the sowing date. This study also provides valuable insights for the selection of suitable cultivars that perform well in soybean cultivation at various durations of maturity.

• Journal of the Korean association of regional geographers
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• v.2 no.1
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• pp.87-114
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• 1996

This paper is the second part of a research which aims to look into the regional development process and the quality of life of Youngnam area. and to suggest a prospect and tasks for the future development of the region. All cities and regions including Youngnam area seem to be involved in a rapidly changing process of conditions for development, because of a recent economic and political transformation in the national and global scale. It can be thus said that, taking such a process into consideration seriously, each city or region needs to establish a long-term prospect and goal, and to set up and practicize its development plan. From this point of view, this paper reconsiders the changing process of conditions for development of Youngnam region, and suggests an alternative development plan. At the first, the changing conditions of regional development are investigated in economic, political, social, cultural and environmental aspects. Secondly, some actual planning practices in this regions are examined and their problems are pointed out. Thirdly, an alternative model for regional development is suggested and development tasks in each aspects are discussed in relation to each other. Finally some regional development strategies are provided in the spatial as well as the sectoral dimision. As a results of this research, it is argued that the development of Youngnam region should pursue both an improvement of socio-cultural and ecological institutions for ensuring humane life of dwellers within the region, and a enforcement of economic and political self-sufficiency in an organic relation between regions and to the whole society. This kind of argument can be applied to every city or region. But it would more significant for Youngnam region, because this region, which once experienced a rapid economic growth but now is fallen into a serious economic stagnation, tends to contrive material plans to redevelop regional economy, while ignoring social plans to improve quality of life.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2009.03a
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• pp.235-236
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• 2009

• Journal of the Korean housing association
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• v.22 no.2
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• pp.63-71
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• 2011

The growth of housing complex in the Housing Development District in local small and medium cities can be defined to process individual lots are possessed by buildings. The study is the basic research of analysis for the internal factors that affect on the each lot, and is for hypothesis of the verification about the Housing Development District growth. So, it can be applied in the Housing Development District of the site conditions and restriction of use of buildings and infrastructure works and the constant boundary of the region. The rate of the development is the occupation of the individual lots per entire lots was limited as the factor of analysis. As above conditions haver no possibility to change in the Housing Development District, the results of this study and further are available to consider. By the results of the connected study, it can be used for Planning and management of the Housing Development District in local small and medium cities. by the adjustment of the relation between growth tendecy and city's properties or district characters.

• KIEAE Journal
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• v.9 no.2
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• pp.17-26
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• 2009

High-rise and high-density apartment complexes have been built and supplied on a large scale in the 1st period New Town of metropolitan areas since the late 1980s. Recently it has become necessary to improve those apartment complexes which have blight problems for aging more than about 20 years accompanying simultaneity and a large scale. The purpose of this study is to analyze actual conditions of high-rise and high-density apartments in a view of sustainable regeneration. The contents and methods of this study are as follows. First, the concept of high-rise and high-density in domestic apartment developments were identified through review of literature and the law. Second, development conditions of Bundang new town and 1st period new town were studied. Third, the evelopment conditions of high-rise and high-density apartments in cases of 6 apartment complexes were analyzed from points of view of sustainable development by literature review and a field study. The results of this study are as follows. First, high-density range in domestic apartments can be conceptualized as 600 persons/ha. High-rise range in domestic apartments can be onceptualized as more than 11 stories under 30 stories. Second, characteristics and subjects based on actual conditions analysis could suggest on physio-environmental aspect and socio-economic aspect. Major characteristics and subjects of the physio-environmental aspect were 1.satisfaction of convenient facilities and public transportation service, 2.shortage of parking space, 3.uniform & blight of community facilities, 4.uniformed building layout, and 5.uniform pattern of unit plan and low flexibility by the bearing wall structure. And those of the socio-economical aspect were 1.satisfaction of current community, 2.increase and diversity of needs of the elderly by socio-demography change, 3.improvement of size and method of apartment complex development and 4.raising of economic-sufficiency.

• Korean journal of food and cookery science
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• v.32 no.6
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• pp.665-676
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• 2016

Purpose: This study was conducted to find the optimal freezing method and storage conditions for welsh onion. Methods: Cut welsh onions (0.3 cm) were packed in nylon/linear low density polyethylene (LLDPE) film bags, and frozen utilizing still-air freezing at -$20^{\circ}C$ (SAF20) and -$40^{\circ}C$ (SAF40), and immersed-liquid freezing at -$40^{\circ}C$ (ILF40); they were then stored at -$20^{\circ}C$ for 7 months. During storage, quality characteristics were measured monthly. Results: Drip loss was the lowest in the ILF40 packaging. Color difference in the stem (white part) did not differ significantly according to freezing conditions and storage time. Color difference in the leaf (green part) and stem was the lowest in SAF20. pH remained unchanged, while total aerobic bacterial count, pyruvic acid and moisture content decreased during storage. Pyruvic acid content of ILF40 was the highest among the freezing treatments. Fructose and glucose contents increased gradually during storage. Citric acid, malic acid, succinic acid and fumaric acid contents were unaffected, regardless of the freezing conditions. Conclusion: The optimal freezing method for welsh onions with the least quality changes was determined to be immersed liquid freezing, following by preservation up to 7 months by freeze-storing.

• Safety and Health at Work
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• v.4 no.2
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• pp.111-116
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• 2013

Background: The aim of this study was to evaluate the quality of the Second Korean Working Conditions Survey (KWCS), focusing on its validity and reliability. Methods: The external validity was evaluated by the assessment of sampling procedures and the response rate, in order to investigate the representativeness of the sample. The content validity was evaluated by the assessment of the development of the questionnaire, and the consistency of questions for the selected construct. The test-retest method was used to evaluate the reliability by means of a phone call survey of 30% of the respondents, who were randomly selected. The respondents' satisfaction regarding the survey procedures and interview time were analyzed to evaluate the quality of survey data. Results: The external validity was assured by an acceptable sampling procedure, rigid multi-stage stratified cluster random sampling. The content validity was also guaranteed by a reasonable procedure for the development of the questionnaire with a pretest. The internal consistency of the questions for work autonomy was maintained, with 0.738 of Cronbach's alpha. The response rate of 36% was lower than that of the European Working Conditions Survey (EWCS), with a contact rate of 66%, compared to 76% for the EWCS. The matching rates of the five retested questions were more than 98% reliable. Conclusion: The quality of the second KWCS was assured by the high external and content validity and reliability. The rigid sampling procedure and development of the questionnaire contributed to quality assurance. The high level of reliability may be guaranteed by the sophisticated field survey procedures and the development of a technical manual for interviewers. The technical strategies for a high response rate should be developed for future surveys.

• Journal of Microbiology
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• v.41 no.1
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• pp.34-40
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• 2003

Aspergillus nidulans, a homothalic ascomycete, has a complete sexual reproductive cycle as well as an asexual one. Both sexual and asexual development are known to be genetically programmed, but are also strongly affected by environmental factors including nutrients, light, temperature and osmolarity. We have examined these factors to define favored conditions for fruiting body (cleistothecium) formation. In general, fruiting body formation was enhanced where carbon and nitrogen sources were sufficient. Limitation of C-source caused predominant asexual development while inhibiting sexual development. When higher concentrations of glucose were supplied, more cleistothecia were formed. Other carbon sources including lactose, galactose and glycerol made the fungus develop cleistothecia very well, whereas acetate caused asexual sporulation only. Organic nitrogen sources like casein hydrolysate and glycine, and an increase in nitrate or ammonium concentration also enhanced sexual development. In addition to nutrient effects, low levels of aerobic respiration, caused either by platesealing or treatment with various chemicals, favored sexual development. Carbon limitation, light exposure and a high concentration of salts promoted asexual development preferentially, suggesting that stress conditions may drive the cell to develop asexual sporulation while comfortable and wellnourished growth conditions favored sexual development.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.2
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• pp.228-234
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• 2004

Dissolved air flotation (DAF), in which suspended solids are removed from water by means of micro-size air bubbles raising slowly up in water and lifting solids from water (smaller than those) attached onto the micro-bubbles as well as those (larger than solids) being attached on these, have been used in water and wastewater since 1920s. The dissolved air flotation technology was originally based on the laminar flow conditions prevailing in water to be treated, but the latest development in that technology has led now to a situation, in which the flow conditions may also be turbulent ones in the modem dissolved air flotation units. Despite of that, the flotation phenomenon used in this unit operation for removal suspended solids from water or wastewater is still the same.