• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.33 no.4
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• pp.23-26
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• 2004

국내$.$외 공기청정기 시장 현황과 개발 동향을 살러보고, 아울러 공기청정기에 적용한 기술과 공기청정기 제품을 간략히 소개한다. 현대인들은 생활이 윤택해짐에 따라 개인과 가족의 건강을 생각하고 즐거운 인생을 살기 위해 노력한다. 이러한 사회적인 흐름에 의해 잘 먹고,잘 살자는 웰빙(Well Being)족이 출현하게 되었고, 건강가전에 대한 소비도 증가하게 되었다. 건강가전은 정수기, 공기청정기, 비데, 연수기, 산소 발생기 등을 꼽을 수 있으며 이중에서 봄철에 가장 관심을 갖는 제품이 공기청정기이다. (중략)

• 한국상하수도협회지
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• s.11
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• pp.12-13
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• 2005

• Product Safety
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• s.58
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• pp.48-52
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• 1997

• Environmental engineer
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• s.92
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• pp.44-45
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• 1994

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.558-564
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• 2021

The water purifier market has increased rapidly in recent years. The welding technology of the evaporator is a key component that determines the level of ice production and the cold water performance of an ice purifier. The finger type evaporator of an ice purifier can remove ice and is divided largely into an instant heat method and a hot gas method. In the hot gas type evaporator, particularly during the production process, the pinhole phenomenon inside the copper pipe and clogging problems occur intermittently when welding high-pressure pipes due to the high-temperature oxygen welding. Its use in a water purifier can cause a problem in that ice and cold water do not form, and repairs cannot be made on site. To solve this problem, in this study, a cap jig was applied to improve the welding defect of the hot gas evaporator. In addition, the oxygen welding flame size was adjusted so that the heat source could be well supplied to the cap jig, and the effectiveness was confirmed through a wave pressure test, a test, and a thermal shock test.

• Environmental and Resource Economics Review
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• v.12 no.4
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• pp.559-577
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• 2003

This paper analyzes household bottled water and water purifier expenditures, taking into account three important characteristics: expenditures may be censored at zero, may be interdependent across expenditure type, and may be endogenously and jointly determined. Censoring, interdependence, and endogeneity of the two expenditures are examined through simultaneous equation bivariate Tobit model. Expenditure function parameters are estimated using a 1997 household survey data collected in Seoul. The study detected interdependence between the two expenditures in the data. Moreover, the coefficient of one expenditure variable is statistically significant in the other expenditure equation. Thus, the overall results show that the simultaneous equation bivariate Tobit model employed here is appropriate for this analysis of the two expenditures. Finally estimated income and household size elasticities of the expenditures are presented.

• Journal of Korean Society of Water and Wastewater
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• v.33 no.5
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• pp.395-404
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• 2019

The point-of-use water dispenser systems are widely used because of convenience in handling and demand for high-quality drinking water. The application has been increased recently in the public places such as department stores, universities and the rest areas in express ways. Improvement of water qualities by the dispenser systems was compared with tap water in this study. The tap water is supplied to the dispenser as the influent of the dispenser system. The twelve dispensers in the public places were used. The five dispensers used reverse osmosis as the main filter and other dispensers used various filters such as ultrafiltration, nanofiltration, and alumina filter. The water quality indicators for sanitation safety, i.e., turbidity and total coliforms, were evaluated. Other water qualities such as pH, residual chlorine, heterotrophic plate count (HPC), and total cell counts were also analyzed. By the point-of-use water dispenser, the turbidity, residual chlorine and pH were decreased and the HPC and total cell counts were increased. The t-test results revealed that the HPC of the tap waters were not significantly different from the treated waters but the total cell counts of the two groups were significantly different. The low pH of the RO filter treatment was also significantly different from the tap waters. This study will contribute to understand the role of the point-of-use water dispenser in improving water quality and to identify key water quality for the proper maintenance of the dispenser systems.

• Plant Journal
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• v.17 no.4
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• pp.35-40
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• 2021

In this study, a technical characteristic test was conducted on the gas turbine generator system of Seoincheon Combined cycle no.6 to derive and verify the model constants. As a result of the generator maximum/minimum reactive power limit test, the maximum reactive power limit is 80 MVar and the minimum is -30 MVar. The generator uses the GENROU model, the field time constant (T'do) is 4.077 s, and the inertial constant (H) is 5.461 P.U. Excitation system used ESST4B model to derive and verify model constants by simulating no-load 2% AVR step test, PSS modeling derived from PSS2A model constants, and simulated and compared measurement data measured when PSS off/on Did. The GGOV1 model was used for the governor-turbine, and the numerical stability of the determined governor-turbine model constant was verified by simulating a 10% governor step test through the PSS/E simulation program

• Membrane Journal
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• v.32 no.2
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• pp.126-132
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• 2022

Water purifiers have a quite different characteristic in comparison with general membrane water treatment processes in which the running and resting are repeated dozens of times a day. In the case of water purifiers using reverse osmosis membranes, this characteristic makes a phenomenon that the total dissolved solids (TDS) of permeate in water purifiers at the beginning of running shows a higher value than a normal value (TDS reduction is lower than a normal value). It is called "TDS creep". The effects of resting times and feed concentrations on the TDS creep were investigated. The feed flushing, the volume increase in permeate side and the flushing with purified water were applied to reduce TDS creep and the effectiveness were observed. Among these trials, the minimization of concentration between feed and permeate side of reverse osmosis membrane like the flushing with purified water can be an ultimate solution to reduce the TDS creep.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.7-9
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• 2006

본 논문에서 사용한 방법은 실제 운전에서 가장 많이 사용하는 전동기 회전자 시정수와 전동기 인덕턴스를 조절하는 것으로 시스템 구조에서 갖는 제어기를 사용하여 다른 전동기 오차에 무관한 정수를 얻는 방법을 사용하여 오차에 대한 민감도가 매우 높은 방법을 채택하였다. 하지만 이 방식에도 정수의 오차를 수동으로 조절하여야 하는 단점을 갖는다. 전동기 정수의 수동 조절은 매우 많은 시간을 투자해야 하는 결함을 갖는다. 따라서 본 논문에서는 전동기의 다른 정수의 오차에 무관하며 민감도가 매우 높은 제어기 구조를 이용하고, 더불어 수동으로 조절하던 번거러움을 제거하여 전동기 정수를 자동조율 기법을 제안하고자 한다.