• Journal of Biosystems Engineering
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• v.26 no.2
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• pp.93-104
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• 2001

A linear chemigation system, integrating agrichemical appication units of pesticide and fertilizer into an irrigation system, was selected as a suitable model for the cost savings in farm management and automation. Technical designs were conducted in the areas of structure, power, drive, control, and hydraulic systems. An experimental farm was sectioned into the fields of 40m by 200m and systemized with the linear-move chemigation system of 36m in span. The chemigation system consisted of a base unit monitoring and controlling overall operation, and a driving unit traveling linearly and injecting agrichemicals. Monitoring and interlocking systems were utilized against unexpected malfunctions of power, injection and drive systems using radio freuency modems between the units. The system can be also modified to various farm sizes and stationary systems of indoor and outdoor.

• Journal of the Korean housing association
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• v.18 no.1
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• pp.11-18
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• 2007

At the economical crisis of Korea in 1997, self-determined price for apartment and the revision increasing the ratio of residential area for mixed-use residential building were introduced to activate the construction industry, which causes construction companies to build super high rise apartment discriminative and high class orientated. This study aims to classify the super high rise building which is planned to build or built recently and to analyze the architectural characteristics. The objects are 288 unit households in 26 apartment complexes higher than twenty five story since 1998. As a result, super high rise building comparing with existing apartments were being varied in plan types of main building and unit household and in construction types. As for the plan, the number of walls having opening to outdoor were increased and it is considered that high rise building can take advantage of a view, lighting and sunshine. The location of living room that used to be in the center of unit in existing apartment was moved freely without rule.

• Journal of the Korean housing association
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• v.14 no.4
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• pp.131-138
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• 2003

The purpose of this study was to examine how the purchasers perceive the effects of the unit characteristics within the complex on the apartment prices. Six major characteristics of the apartments : orientations and floors; views; structures; conditions and maintenances of interior materials; interior alterations; and access to the outdoor facilities were included for the analysis. The data were gathered from 284 households in seven private apartment complexes in Ulsan. It was found that the price of the apartment was higher if it was southward, on the royal or semi-royal floors, with the nice view for the riverside or any other landscape resources, or openness. Other characteristics which increase the price were the hall type not the corridor one, inner side of the building, good conditions of interior materials, and extended balcony.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.1191-1196
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• 2007

This research presents a laboratory study about an annoyance of impulsive sound caused by construction site(breaker and blasting). The sources are sampled from outdoor noise and their levels range from 40 to 75 dB at the interval of 5dB. The noise unit is based on A-weighted sound exposure level (ASEL; $L_{AE}$). To make equal ASEL of outdoor noise, finite impulse response (FIR) filter is applied to the originally sampled source to include the effect of distance attenuation. The evaluation method of jury test adopted a Semantic Difference Method (SDM). In the result of the Jury test for impulsive noise, the annoyance response of blasting noise was higher than that of breaker noise.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.714-720
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• 2008

This research presents a laboratory study about an subjective response of impulsive sound caused by leisure shooting. The sources are sampled from outdoor noise and their levels range from 40 to 75 dB at the interval of 5dB. The noise unit is based on A-weighted sound exposure level (ASEL; $L_{AE}$). To make equal ASEL of outdoor noise, finite impulse response (FIR) filter is applied to the originally sampled source to include the effect of distance attenuation. The evaluation method of the jury test adopted a Semantic Difference(SD) Method. In the result of the jury test for impulsive noise, the mean response rating expressed a linear relation and %HA(percent highly annoyed) displayed a exponential growth relation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.04a
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• pp.594-601
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• 1997

Propeller fans are commonly equipped in outdoor units of air-conditioners to provide effective cooling in a dried heat exchanger. A new design technique was developed to satisfy requirements of aerodynamic and aeroacoustic performance, which employs the intersection method of two cylinders for mean camber line. Three proto-types of propeller fan including Palm-Shaped, Highly-Swept(PSHS) fan (proto 3)were not only to provide low lift forces for dipole sound, but also to reduce the organized tip vortices interacting with the fan guide causing narrow-banded rotating instabilities. Cross-correlation technique was applied to study flow noise source characteristics for three proto-type fans designed. The cross-correlations between a microphone at far field and a hot-wire sensor at near field show that flows near hub region of proto 3 fan are less organized and the flow structures especially at high flow rate coefficients for proto 3 fan are less correlated with noise generated than other proto-types fans.

• Environmental and Resource Economics Review
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• v.11 no.1
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• pp.1-29
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• 2002

Faced with large scale of outdoor recreation resources and variety of demanders' desire, it would be necessary for the managers to estimate the values of individual attributes rather than a bundle of characteristics of outdoor recreation sites. By extending the Brown and Mendelsohn's (1984) approach we are able to estimate the beneficial effects of the improvement of individual attributes. Sampling 208 fishermen who visited 11 free fishing sites located in Daegu and Gyeongbuk, the functions of marginal willingness to pay for scenery and non-crowdedness were estimated. If 1 unit of scenery could be improved from its average value a fisherman, on average, would receive benefit of as much as 3,840 won. The average beneficial effect of the non-crowdedness improvement would amount to 2,220 won.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.12
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• pp.999-1006
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• 2006

A study of temperature profiles in mixing zone of AHU (air handling unit) can contribute greatly to enhance performance of AHU system, so the study on the temperature distribution between RA (return air) and OA (outdoor air) is important to analyze the mixing characteristics in a mixing zone of AHU. Accordingly, the temperature profiles during RA (return air) and OA (outdoor air) supply process into mixing zone of AHU with an air mixer are studied experimentally. The effect of air mixer, OA temperature and RA/OA flow rate are studied in detail. In this study, the results show that the mixing efficiency is all high for installed the air mixer. The more OA temperature increase and OA flow rate decrease, the more mixing efficiency is high.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.8
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• pp.567-572
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• 2010

Air shift type heat pump is combined heat recovery ventilator and refrigerator, and it is installed an air shifter changing air flow. And so it is an perfect AHU(Air Handling Unit) capable to cooling, heating, ventilation and heat recovery. Therefore, an experimental study has been carried out to investigate the operating performance in winter for this system. An experimental data are room temperature, inlet/outlet temperature of condenser, evaporator and heat exchanger. They have been measured as the variation of outdoor temperature. The results, in case of rising above freezing, the air shift type heat pump system is operated normally, and the heating COP is 3.0~4.2 by varying outdoor temperature from $-3^{\circ}C$ to $15^{\circ}C$.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2358-2361
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• 2003

In this paper, parallel control method that enables coordinating operations of multiple mini ice storage air conditioner is proposed based on LonWorks system. The proposed parallel control method is a kind of master/slave control method based on LonTalk network communication. In the control method, master controller leading whole system operations is determined by date to avoid the disproportion of outdoor unit operations. In addition to the above, duty shift control method is proposed to avoid redundant operations of outdoor units and to equalize the operation frequencies of them. Through some simulation tests, the proposed parallel control method and the duty shift control method are evaluated and the efficiencies of them are validated by comparing with existing methods.