• Journal of the Korea Furniture Society
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• v.16 no.1
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• pp.53-69
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• 2005

This research has a significant meaning to observe and understand the historical condition of a furniture industry and the characteristics of Korean home furniture's formation, ability, skill and materials from 1980s when there were an economic growth and a historical development of Korean home furniture occurred to present days. During 1980s, there was an automatic system available and has enforced and settled the standards on its quality and price in a furniture industry. Also, there was a big trend of black furniture as well as an entrance of corporation and high glossy furniture due to technical cooperation from Europe. In 1990s, there was an entrance of furniture which various techniques was applied due to a high development of the materials and skills, and also various sizes of height and weight and enlargement of acceptance function using highly-technological hardware. After 2000 and now, pro-environmental products is embossed in the Korean home furniture where they added a public issue which is the concept of well being, and A.I and sub material has been pro-environment. There also was a natural unity between nature and technology because of increased usage of trees with its natural patterns, metals, and glasses. For the future development of home furniture design, This problem should be promptly recognized that current home furniture designs are now on the verge of being lack of originality and are just following the market demand and recent trend as it is. Then, there should be a development of its specialized, detailed, unique design as well as a development of advanced materials, production management, distribution, and so on, and carrying out a diversified research continuously. There also should be a systematic education, which is necessary for training specialists to lead the Korean home furniture design industry as well as preparing a basic level for the future without a negligence.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.6 no.3
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• pp.1-8
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• 2003

This study was carried out in order to investigate of effects of environmental conditions which influence negative ions development. Negative ions are nature' most powerful air-cleaning agents, are created by nature, and found at their most optimal levels where the air is most pure and healthy. Negative ions are regarded as one of the important factors which indicate the quality of the air. Therefore, the focus of this study was to clear relationship among negative ions development induced by plant cultivar and environmental conditions such as air temperature, light intensity and relative humidity. As the results of this study, it was found that negative ions development was promoted during the period with plants compared to the period without plants. In Particular, negative ions development was high under air temperature $20^{\circ}C$, relative humidity 90% and dark condition. Temperature and humidity factors on this experiment was strongly affected on negative ions development, but light intensity had almost slight effect. It was shown that these results can contribute to the application of environmental control techniques to negative ions. Among plant cultivar of Spathiphyllum spp. Mentha spicata, and Cupressu arizonica, Mentha spicata was higher negative ions than the other plants, and also the leaves were higher than the stems and roots. The effect of plants on the perception of the inte끼r air quality may, therefore, be one explanation of this results about negative ions. on the other hand, it seems that a green indoor environment might be an increase in general well-being due to the plants.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.6 no.3
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• pp.35-45
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• 2003

This study was performed to suggest growth status data of the large old trees as the natural monuments of Korea. Field investigation of 70 large old trees as the natural monuments of Korea was carried out in Seoul, Inchon, Kyungki, Chungbuk, Chungnam, Chonbuk, Chonnam. The main field of this study is classified into the growth condition, soil state and management situation. The results of this study are below : The age distribution of the large old trees as the natural monuments of Korea is as follows : above l00years in 5.9%, above 200years in 8.9%, above 300 years in 11.8%, above 400 years in 16.2%, above 500 years in 16.2% and above 600years in 41.1%. Location types of the large old trees as the natural monuments of Korea are found in 11 types; the types are hill side(22.9%), historical monument area(15.7%), field(l4.3%) and building area(12.9%), etc. Also, growth type of the trees is individually placed. In the aspect of soil environment, the acidification of soils has been appearing in all surveyed areas, and the soil of Seoul area has much acidum phosphoricum because of excessive fertilizer. Finally, in management situation. major factors inhibiting growth of the large old trees as the natural monuments of Korea are soil covering of protruded root above ground, soil hardening by human, embankments, small area that has been surrounded fence. Continuous monitoring and accumulation of status data are necessary to preserve the large old trees as the natural monuments of Korea.

• Journal of the Korean Society of Clothing and Textiles
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• v.21 no.1
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• pp.19-34
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• 1997

The goals of this study are to suggest the guidance for automated clothing manufacture by analysis the technology of the automated manufacturing facilities and to propose how improve the efficiency of the production planning and management for automated clothing manufacture In this study, the research about the automated clothing manufacturing machines and the analysis about the modules and functions of apparel information systems were performed. In order to understand the factory automation of the larger clothing firms, the case study method was used. The case study samples were 3 clothing firms. The results and suggestions are as follows: 1. An information technology for automated clothing manufacture has enabled the computer integrated manufacturing system to connect production planning and management part with each work station on the factory floor. 2. The apparel information system to integrate and manage manufacturing informations from each workstation and the apparel CAD system are used in the department of production planning. At the cutting room, there are automated manufacturing machines like an automatic spreading system and an automatic cutting system. Sewing room has the computer controlled unit production system and semi-automated sewing machines. In addition, in the finishing room, an automatic packing machine and a press system are used and besides a warehousing system has been developed. Considering these available technology, for better product efficiency, it is necessary to consider and utilize the specific character of these automatic manufacturing machines and computer system whether they proper to each product style. 3. Most of the clothing manufacturers are in the stage of semi-automated manufacture. In order to improve the manufacturing environment, it is needed to gradual procedure of manufacturing automation with considering the firm's financial condition, existing facilities and staffs operating machines. The case study sample firms are in the high degree of manufacturing automation. They can accomplish the flexible manufacturing system to link the information system with each work station menufacturing system by computerized control. For the case of the firm having already used the computer integrated manufacturing and managing system, it is necessary that the function to deal with drawing information is added to the retaining module of the apparel system.

• Journal of Marine Bioscience and Biotechnology
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• v.11 no.2
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• pp.52-61
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• 2019

Over the past few decades, microalgae-based biotechnology conjugated with innovative CRISPR/Cas9-mediated genetic engineering has been attracted much attention for the cost-effective and eco-friendly value-added compounds production. However, the discharge of reproducible living modified organism (LMO) into environmental condition potentially causes serious problem in aquatic environment, and thus it is essential to assess potential environmental risk for human health. Accordingly, in this study, we monitored discharged genetically modified microalgae (GMM) near the research complex which is located in Daejeon, South Korea. After testing samples obtained from 6 points of near streams, several green-colored microalgal colonies were detected under hygromicin-containing agar plate. By identification of selection marker genes, the GMM was not detected from all the samples. For the lab-scale environmental risk assessment of GMM, acute toxicity test using rotifer Brachionus calcyflorus was performed by feeding GMM. After feeding, there was no significant difference in mortality between WT and transformant Chlamydomonas reinhardtii. According to further analysis of horizontal transfer of green fluorescence protein (GFP)-coding gene after 24 h of incubation in synthetic freshwater, we concluded that the GFP-expressed gene not transferred into predator. However, further risk assessments and construction of standard methods including prolonged toxicity test are required for the accurate ecological risk assessment.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.4
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• pp.62-69
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• 2013

Visual demands associated with in-vehicle display usage and text messaging distract a driver's visual attention from the roadway. To minimize eyes-off-the-road demands, voice interaction systems are widely introduced. Under cognitively distracted condition, however, awareness of the operating environment will be degraded although the driver remains oriented to the roadway. It is also know that the risk of inattentive driving varies with age, thus systematic analysis of driving risks is required for the older drivers. This paper aims to understand the age-related driving performance degradation and visual attention changes under auditory cognitive demand which consists of three graded levels of cognitive complexity. In this study, two groups, aged 25-35 and 60-69, engaged in a delayed auditory recall task, so called N-back task, while driving a simulated highway. Comparisons of younger and older drivers' driving performance including mean speed, speed variability and standard deviation of lane position, and gaze dispersion changes, which consist of x-axis and y-axis of visual attention, were conducted. As a result, it was observed that gaze dispersion decreased with each level of demand, demonstrating that these indices can correctly rank order cognitive workload. Moreover, gaze dispersion change patterns were quite consistent in younger and older age groups. Effects were also observed on driving performance measures, but they were subtle, nonlinear, and did not effectively differentiate the levels of cognitive workload.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.4
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• pp.413-422
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• 1995

Cavitation erosion-corrosion implies damage to materials due to the shock pressure or shock wave that results when bubbles form and collapse at a metal surface within a liquid. If the liquid is corrosive to the material, a condition typically encountered in industry, the component materials may suffer serious damage by a combination of mechanical and electrochemical attack. In this study, the mild steel(SS41) was tested by using the piezoelectric vibrator with 20kHz, 24$\mu$m to cavity generation apparatus. The damage behaviour of vibration cavitation erosion-corrosion and the environment characteristics were investigated in various solutions which are seawater, tap water and distilled water. The main results obtained are as follows; 1) The cavitation erosion-corrosion damage behaviour in the seawater increases to occur at the equal degree on the middle portion and the outside portion of specimen. The distilled water specimen, on other hand, occurs beginning on the outside portion across to the middle portion of specimen. 2) The cavitation erosion-corrosion damage in the tap water of low specific resistance more increases than that in the distilled water of high specific resistance at the initial testing time and more decreases than that in it by the CaCO sub(3) film with testing time. 3) Cavitation erosion-corrosion damage characteristic divides into four regions; incubation region, acceleration region, deceleration region and steady state region.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.4
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• pp.330-338
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• 1999

Extensive research has been conducted on effects of drought stress on growth and development of soybean but information is rather restricted on the limited-irrigation system by way of precaution against a long-term drought condition in the future. The experiment for limited-irrigation was conducted in transparent vinyl shelter at Asian Vegetable Research and Development Center (AVRDC), Taiwan in 1997. Two soybean varieties, Hwangkeum and AGS292, improved in Korea and AVRDC, respectively were used for this experiment. The relationships between normalized transpiration rate (NTR) and fraction of transpirable soil water (FTSW) in both varieties were similar that the NTR was unchanged until FTSW dropped to about 0.5 or 0.6. At FTSW less than those values, NTR declined rapidly. Days required to harvest in both varieties were significantly prolonged at IR6 treatment compared to any other treatments. Daily mean transpiration rate was significantly higher at IR5 treatment, as averaged over varieties. Similarly, water use efficiency was also high at 1R5 treatment. In both varieties, seed yield was the greatest at the IR5 treatment, as compared to any other limited-irrigation treatments, due to the increased seed number and high transpirational water use efficiency. The indices of input water and seed yield for the different limited-irrigation treatments against control indicated that Hwangkeum produced 59.6% or 60.7% of seed yield using 36.1% or 44.9% of input water, as compared to control, by irrigation at only R5 or R6 stages, respectively. The AGS292 produced 56.1% of seed yield with 35.4% of input water of control, when irrigated at R5 stage. The results of this study have elucidated that the limited irrigation at R5 stage in soybean can be minimized yield loss with such small quantity of water under the environment of long-term drought stress and the expected shortage of agricultural water in the future.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.339-344
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• 2005

A PEMFC system model for FCEV was constructed and simulated numerically to examine the heat/water flow of the system and air/fuel humidification process for various operation conditions (ambient pressure /temperature/humidity, operating temperature, power load). We modeled PEMFC stack which can generate maximum electricity of about 80 kW. This stack consists of 400 unit cells and each unit cell has $250cm^2$ reacting area. Uniform current density and uniform operating voltage per each cell was assumed. The results show the flow characteristics of heat and water at each component of PEMFC system in macro-scale. The capacity shortage of the radiator occurred when the ambient was hot $(over\;40^{\circ}C)$ and power level was high (over 50 kW). In spite of some heat release by evaporation of water in stack, heat unbalance reached to 20kW approximately in such a severe operating condition. This heat unbalance could be recovered by auxiliary radiators or high speed cooling fan with additional cost. In cold environment, the capacity of radiator exceeded the net heat generation to be released, which may cause a problem to drop the operating temperature of stack. We dealt with this problem by regulating mass flow rate of coolant and radiator fan speed. Finally, water balance was not easily broken when we retrieved condensed and/or unused water.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.59-63
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• 2005

The 800-kW PM (permanent magnet) synchronous generator is developed as a wind power generator. The matching converter is designed to control the torque and power depending on the wind speed regime. The generator starts to generate the power at the speed of 9 rpm and the rated output is generated at the speed of 25 rpm. The rated output power of an inverter is 750 kW when the PM synchronous generator is delivering 800 kW to the inverter. The inverter is specially designed to perform the maximum power point tracking (MPPT) at the low wind speed regime that is typical wind environment in Korea. The inverter test was done with a 2 MW M-G system at KERI (Korea Electric Research Institute). The M-G set has a 2 MW motor driver and a 38:1 gear to match the speed between the motor and the PM generator. The torque simulating the wind is applied to the PM generator by a DC motor. The test results show the inverter efficiency of $94.3\%$ at the rated power generating condition. The measured values show that the MPPT algorithm is working well. Overall reliability will be verified through the long-term site test.