• Journal of Biosystems Engineering
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• v.25 no.3
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• pp.213-220
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• 2000

Grafting of fruit-bearing vegetables has been widely used to increase the resistance to soil-borne diseases, to increase the tolerance to low temperature or to soil salinity, to increase the plant vigor, and to extend the duration of economic harvest time. After grafting, it is important to control the environment around grafted seedlings for the robust joining of a scion and rootstock. Usually the shading materials and plastic films are used to keep the high relative humidity and low light intensity in greenhouse or tunnel. It is quite difficult to optimally control the environment for healing and acclimation of grafted seedlings under natural light. So the farmers or growers rely on their experience for the production of grafted seedling with high quality. If artificial light is used as a lighting source for graft-taking of grafted seedlings, the light intensity and photoperiod can be easily controlled. The purpose of this study was to develop a prototype system for the graft-taking enhancement of grafted seedlings using artificial lighting and to investigate the effect of air current speed on the distribution of air temperature and relative humidity in a graft-taking enhancement system. A prototype graft-taking system was consisted by polyurethane panels, air-conditioning unit, system controller and lighting unit. Three band fluorescent lamps (FL20SEX-D/18, Kumho Electric, Inc.) were used as a lighting source. Anemometer (Climomaster 6521, KANOMAX), T-type thermocouples and humidity sensors (CHS-UPS, TDK) were used to measure the air current speed, air temperature and relative humidity in a graft-taking system. In this system, air flow acted as a driving force for the diffusion of heat and water vapor. Air current speed, air temperature and relative humidity controlled by a programmable logic controller (UP750, Yokogawa Electric Co) and an inverter (MOSCON-G3, SAMSUNG) had an even distribution. Distribution of air temperature and relative humidity in a graft-taking enhancement system was fairly affected by air current speed. Air current speed higher than 0.1m/s was required to obtain the even distribution of environmental factors in this system. At low air current speed of 0.1m/s, the evapotranspiration rate of grafted seedlings would be suppressed and thus graft-taking would be enhanced. This system could be used to investigate the effects of air temperature, relative humidity, air current speed and light intensity on the evaportranspiration rate of grafted seedlings.

• Journal of Korean Society for Atmospheric Environment
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• v.5 no.1
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• pp.68-78
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• 1989

The heavy metal of suspended particulates with human health has long been studied in environmental interest concerned. This study was intended to identify harmful heavy metals of the ambient air borne dusts which were related with the respirable sizes in the aerodynamics. Two sampling sites were selected comparatively; one was in the Shinchon area, which is the commercial district with heavy traffic and the other site was in the Bulgwang area which is residential area. The supended particulates were sampled by high volume air sample with 6 cascade impactor stages. The heavy metals in terms of As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, V and Zn were determined by stomic absorption spectrometry or inductively coupled plasma emission spectrometry. The samples weretaken bimothly for seven consecutive days from May 1987 to March 1988. The annual average concentration of the respirable suspended dust of which diameter is less than 10$\mum$ was 152.59 $\mug/m^3$ of the Shinchon air samples; the respirable dust was equivalent to approximately 85% of the total suspended particulates. The annual average concentration of the respirable suspended dust of the Bulgwang air samples was 112.56 $\mug/m^3$; that was approximately 86% of the total suspended particulates. The concentration of heavy metals was investigated in relation to the particle size. The concentration of Cr, Fe, Mn and V were tended to be much more in the coarse particles than in the fine particles. Cd and Pb in the fine particles were more than in the coarse particles. In the partial correlation coefficients; in the Shinchon area, high correlations among Fe, Se and Mn were determined; it is assumed that those sources would be originated from coal, gasolineand diesel. In Bulgwang area, would be high correlation among Fe, Se, Hg and Mn considered to be originated from coal, Bunker-C and heavy oil as well. From the above results, the hazardous heavy merals in air should be measured and controlled in originally their sources.

• The Korean Journal of Mycology
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• v.13 no.2
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• pp.115-121
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• 1985

An aerial survey for fungal flora in Seoul has been carried out by Petri plate exposure method for a period of one year. A total of 2227 fungal spores appeared in the plates. Of these, Cladosporium was the commonest fungus representing 43.5% of the total spore count followed by Penicillium (15.8%). Alternaria (10.5%), and Aspergillus (3.8%). There were seasonal variations in the prevalence of fungal spores. The occurrence of these fungi was greatly affected by climatic conditions. However, Alternaria appeared to prefer warmer weather. A comparison of fungal population from the outdoor and indoor air was also investigated to support the view that Alternaria is abundant population from the outdoor air and that Cladosporium from the indoor air depending on their availability in the atmosphere.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.403-408
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• 2001

Structure-borne noise and vibration is one of the main complaints of home appliances such as refrigerators, washing machines, air conditioners, etc. There have been many efforts to reduce the emitting noise and vibration. Mostly the efforts have been concentrated to optimize the mounts shape and its material properties realizing that the vibration power is mainly transmitted to the structure via mounts. It is known that softer mounts have the better vibration isolation effect. But mounts have another important function in addition to the vibration isolation. That is to support the motor and compressor safely. Thus mounts should be stiff enough to resist the supporting items. But the two properties, stiff and soft, are contradict each other. So the designer should compromise the two complicity properties properly in between. Noticing that, motors and compressors themselves are very quite until they are connected to the base structure via mounts, wire connecting idea was proposed in this work. Instead of using conventional mounts, as shown in Fig 4, compressor was mounted using six wires as shown in Fig 5. Since wire is very flexible in bending but stiff in tension, we can realize the ideal mount design requirements, stiff enough to support and soft enough to isolate vibration power. The suggesting idea was tested with an air conditioner outdoor unit.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.11
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• pp.1222-1230
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• 2009

A theoretical model was developed to compute the effect of a bubble layer in reducing the radiation noise generated by a force applied on an infinite flat plate considering the noise of multi-bubbles. Using the model, the effectiveness of a bubble layer in reducing the structure-borne noise of the plate was evaluated to consider various parameters such as the source noise levels, the thickness of bubble layers, the volume fractions and the frequency characteristics of bubbly fluids. Considering the noise of multi-bubbles, the actual reduction effect of radiation noise using a bubble layer was expected in cases of high source levels, high volume fractions of bubbles and large thickness of the bubble layer above the resonance frequency of the bubble layer. Accordingly, it is recommended that the thickness of a bubble layer, the source noise level and the characteristics of bubbly fluids should be optimized cautiously to maximize noise reduction effects.

• The Korean Journal of Mycology
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• v.21 no.1
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• pp.77-84
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• 1993

Out of 210 tinea capitis cases studies, 16 were negative when examined with KOH, among the remaining 194 cases, 123 were males (63.4%) and 71 were females (36.6%) and the age of incidence ranged between 7 and 15 years. Microsporum was the main causal agent being identified in 82 cases (42.3%) and was represented by 5 species among which M. canis was common in Egypt (55 cases, 28.4%). Trichophyton constituted 32% and was represented by 8 species among which T. violaceum was the most common (24.2% of total cases). Candida were isolated from 3.6% of total cases. The 47 species and twenty-five genera from nondermatophyte-cyclohexamide resistant fungi were recovered from the diseased skin tissue. Penicillium and Aspergillus were the most abundant followed by Scopulariopsis, Alternaria, Thermoascus, Chrysosporium and Cladosporium. Studies of the air-borne fungi in-door the hospital wards revealed the occurrence of 57 species belonging to 28 genera, among which Aspergillus flavus, Penicillium chrysogenum, p. corylophilum, A. niger, Tritirachium rosum and Alternaria alternata were the most common. Results of the out-door experiments were basically similar to those of the in-door experiments.

• Korean Journal of Remote Sensing
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• v.28 no.6
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• pp.693-704
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• 2012

Space-born remote sensing camera systems tend to be developed to have very high performances. They are developed to provide extremely small ground sample distance, wide swath width, and good MTF (Modulation Transfer Function) at the expense of big volume, massive weight, and big power consumption. Therefore, the camera system occupies relatively big portion of the satellite bus from the point of mass and volume. However, the camera systems for lunar exploration don't need to have such high performances. Instead, it should be versatile for various usages under various operating environments. It should be light and small and should consume small power. In order to be used for national program of lunar exploration, electro-optical versatile camera system, called MAEPLE (Multi-Application Electro-Optical Payload for Lunar Exploration), has been designed after the derivation of camera system requirements. A ground model of the camera system has been manufactured to identify and secure relevant key technologies. The ground model was mounted on an aircraft and checked if the basic design concept would be valid and versatile functions implemented on the camera system would worked properly. In this paper, results of design and functional test performed with the field campaigns and air-born imaging are introduced.

• Special Issue of the Society of Naval Architects of Korea
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• 2011.09a
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• pp.43-46
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• 2011

The noise characteristics of multi-purpose dive support vessel show the different patterns such as types of noise sources, accommodation arrangement and etc due to its operation. Especially, the tunnel and retractable thruster for the dynamic positioning should be considered at the noise analysis. The floating floor is selected as the main measure of noise reduction and is constructed at the deck near the noise sources. In this paper, the noise analysis of dive support vessel is based on the estimation of noise sources and floating floor and SEA (Statistical Energy Analysis) is used for analysis of the air-born noise and structure-borne noise. The noise analysis of air conditioning system is also carried out and the noise results of cabin room are reviewed.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.5
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• pp.969-974
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• 2021

South Korea is making efforts to select a drone industry, a type of unmanned aerial vehicle, as one of the 7 major industries in the country, to select a drone-specific liberalization zone and to establish and revise a drone-related bill. Through these efforts, drone delivery and drone taxis are expected to be operated in the future. Therefore, a multilateral collision avoidance system with existing aircraft such as drones, fixed-wing and rotary-wing should be established to prepare for possible drone and air-borne collisions.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.814-819
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• 2005

There is growing consciousness of the environmental performance of buildings in Hong Kong. The Buildings Department, the Lands Department and the Planning Department of the Hong Kong Government issued the first of a series of joint practice notes [1] to promote the construction of green and innovative buildings. Green features are architectural features used to mitigate migration of noise and various air-borne pollutants and to moderate the transport of heat, air and transmission of daylight from outside to indoor environment in an advantageous way. This joint practice note sets out the incentives to encourage the industry in Hong Kong to incorporate the use of green features in building development. The use of green features in building design not only improves the environmental quality, but also reduces the consumption of non-renewable energy used in active control of indoor environment. Larger window openings in the walls of a building may provide better natural ventilation. However, it also increases the penetration of direct solar radiation into indoor environment. The use of wing wall, one of the green features, is an alternative to create effective natural ventilation. This paper therefore presents a preliminary numerical study of its ventilation performance using Computational Fluid Dynamics (CFD). The numerical results will be compared with the results of the wind tunnel experiments of Givoni.