저항을 이용한 프로판-공기 혼합가스의 점화한계 개선에 관한 연구

이춘하,오종용,옥경재,지승욱,이광식,심광렬 한국화재소방학회 2004 한국화재소방학회논문지 Vol.18 No.1

본 논문은 IEC형 불꽃점화 시험장치를 이용하여 저압 유도회로의 최소 점화한계를 프로판-공기 5.25 Vol.%의 혼합 가스에 대하여 실험적으로 구하였으며, 또한 유도회로의 인덕턴스 L에 안전소자로서 저항을 병렬접속하였을 경우 프로판-공기 5.25 Vol.%의 혼합 가스에 대한 점화한계 개선효과를 관찰하였다. 그 결과, 최소 점화한계는 전류의 크기에 따라 좌우되었다 또한, 전원으로부터 공급되는 에너지는 인덕턴스에 우선 축적되고. 그 초과분의 에너지가 폭발성 가스의 점화원으로 작용하였다. 점화한계 개선효과는 인덕턴스가 300 mH일 때, 최고 330%의 개선효과가 나타났으며 인덕턴스가 클수록 점화한계 개선효과가 크게 나타났다. 또한 병렬로 접속한 저항의 크기가 적을수록 점화한계 개선 효과가 크다. 본 연구결과는 본질안전 방폭형 전기기기의 연구개발을 위한 기본자료로 활용할 수 있을 뿐만 아니라 이들 기기의 방폭성능에 대한 시험자료로도 활용이 가능할 것으로 사료된다. This paper describes the minimum ignition limits for propane-air 5.25 Vol.% mixture gases in low voltage inductive circiuts. The improved effects on the ignition limit are studied by parallel safety components(resistors) for propane-air 5.25 Vol.% mixture gas in low voltage inductive circuits. The experimental devices used in this test are the IEC type spark ignition test apparatus. The minimum ignition limits are controlled by the values of current in inductive circuit. Energy supplied from elect source is first accumulated at the inductance, it's extra energy is working as ignition source of the explosive gas. The improved effects on the ignition limit are respectively obtained as the maximum rising rate of 330% by composing parallel circuits between inductance and resistor as compared with disconnecting inductance with the safety components. The more values of inductance increase the higher improved effects of ignition limit rise. The less values of resistor the higher improved effects of ignition limit rise. It is considered that the result can be used for not only data for researches and development of intrinsically safe explosion-proof machines which are applied equipment and detectors used in dangerous areas but also for datum for its equipment tests.

InGaAsP/InP Buried-Ridge Waveguide Laser with Improved Lateral Single-Mode Property

Su Hwan Oh,Ki Soo Kim,Oh Kee Kwon,Kwang Ryong Oh 한국전자통신연구원 2008 ETRI Journal Vol.30 No.3

A novel InGaAsP/InP buried-ridge waveguide laser diode structure is proposed and demonstrated for use as a single-mode laser. The lateral mode of the proposed device can be controlled by adjusting the composition and thickness of the InGaAsP layer grown over the active region. Stable single-mode operation without kinks or beam-steering is achieved successfully with lateral and transverse in the junction plane even for the device with the ridge width of 9 μm up to an injection current of 500 mA.

Short-term Evaluation of a Comprehensive Education Program Including Inhaler Training and Disease Management on Chronic Obstructive Pulmonary Disease

( Kwang Ha Yoo ),( Wou Young Chung ),( Joo Hun Park ),( Sung Chul Hwang ),( Tae-eun Kim ),( Min Jung Oh ),( Dae Ryong Kang ),( Chin Kook Rhee ),( Hyoung Kyu Yoon ),( Tae-hyung Kim ),( Deog Kyeom Kim ) 대한결핵 및 호흡기학회 2017 Tuberculosis and Respiratory Diseases Vol.80 No.4

Background: Proper education regarding inhaler usage and optimal management of chronic obstructive pulmonary disease (COPD) is essential for effectively treating patients with COPD. This study was conducted to evaluate the effects of a comprehensive education program including inhaler training and COPD management. Methods: We enlisted 127 patients with COPD on an outpatient basis at 43 private clinics in Korea. The patients were educated on inhaler usage and disease management for three visits across 2 weeks. Physicians and patients were administered a COPD assessment test (CAT) and questionnaires about the correct usage of inhalers and management of COPD before commencement of this program and after their third visit. Results: The outcomes of 127 COPD patients were analyzed. CAT scores (19.6±12.5 vs. 15.1±12.3) improved significantly after this program (p<0.05). Patients with improved CAT scores of 4 points or more had a better understanding of COPD management and the correct technique for using inhalers than those who did not have improved CAT scores (p<0.05). Conclusion: A comprehensive education program including inhaler training and COPD management at a primary care setting improved CAT scores and led to patientsc better understanding of COPD management.

Widely tunable multichannel grating cavity laser

Oh Kee Kwon,Jong Hoi Kim,Kang Ho Kim,Eun Deok Sim,Kwang Ryong Oh IEEE 2006 IEEE photonics technology letters Vol.18 No.16

<P>A widely tunable grating cavity laser based on the Rowland circle construction for a concave grating is proposed and demonstrated. The device is implemented by employing multichannel array structure in a Littman configuration and fabricated by integrating all elements in an InP substrate. Only one channel is turned on at a time, with coarse tuning realized by selecting the appropriate element in the channel array and fine tuning by controlling the beam deflection provided by dispersive element. An overall tuning range of 50 nm with a sidemode suppression ratio of more than 30 dB has been achieved for the six-channel device.</P>

200 GHz-spacing 8-channel multi-wavelength lasers for WDM-PON optical line terminal sources

Oh, Su Hwan,Shin, Jang-Uk,Kim, Ki Soo,Lee, Dong-Hoon,Park, Sang-Ho,Sung, Hee-Kyung,Baek, Yong-Soon,Oh, Kwang-Ryong The Optical Society 2009 Optics express Vol.17 No.11

<P>We have fabricated modules of 8-channel multi-wavelength lasers (MWLs) with a wavelength separation of 200 GHz for the wavelength division multiplexed-passive optical network (WDM-PON) optical line terminal sources. The variation in the output power is minimized by inserting silicone between the superluminescent diode (SLD) and the silica waveguide. The wavelength shift of each channel is less than 0.21 nm from the ITU grid and can be controlled in the range of 0.36 nm without any reductions of the output power by a tuning heater. MWLs operated successfully in the direct modulation for 1.25 Gbit/s transmissions over 20 km.</P>

Corrigendum : Corrigendum: Comparative Analysis of Human Epidermal and Peripheral Blood γδ T Cell Cytokine Profiles

( Kwang Mi Kim ),( Ji Yeon Han ),( Tae Ryong Lee ),( Dong Wook Shin ),( Hak Chang ),( A Ri Cho ),( Soon Jin Choi ),( Seong Jin Jo ),( Oh Sang Kwon ) 대한피부과학회 2014 Annals of Dermatology Vol.26 No.4

Short-term Evaluation of a Comprehensive Education Program Including Inhaler Training and Disease Management on Chronic Obstructive Pulmonary Disease

Yoo, Kwang Ha,Chung, Wou Young,Park, Joo Hun,Hwang, Sung Chul,Kim, Tae-Eun,Oh, Min Jung,Kang, Dae Ryong,Rhee, Chin Kook,Yoon, Hyoung Kyu,Kim, Tae-Hyung,Kim, Deog Kyeom,Park, Yong Bum,Kim, Sang-Ha,Yum, The Korean Academy of Tuberculosis and Respiratory 2017 Tuberculosis and Respiratory Diseases Vol.80 No.4

Background: Proper education regarding inhaler usage and optimal management of chronic obstructive pulmonary disease (COPD) is essential for effectively treating patients with COPD. This study was conducted to evaluate the effects of a comprehensive education program including inhaler training and COPD management. Methods: We enlisted 127 patients with COPD on an outpatient basis at 43 private clinics in Korea. The patients were educated on inhaler usage and disease management for three visits across 2 weeks. Physicians and patients were administered a COPD assessment test (CAT) and questionnaires about the correct usage of inhalers and management of COPD before commencement of this program and after their third visit. Results: The outcomes of 127 COPD patients were analyzed. CAT scores ($19.6{\pm}12.5$ vs. $15.1{\pm}12.3$) improved significantly after this program (p<0.05). Patients with improved CAT scores of 4 points or more had a better understanding of COPD management and the correct technique for using inhalers than those who did not have improved CAT scores (p<0.05). Conclusion: A comprehensive education program including inhaler training and COPD management at a primary care setting improved CAT scores and led to patients' better understanding of COPD management.

미역을 함유한 압출성형물의 이화학적 특성에 관한 연구

김동수,오상룡,조길석,조진호,김영명,구재근,도정룡,문광덕 한국수산학회 1994 한국수산과학회지 Vol.27 No.1

본 연구에서는 우리나라의 연근해에서 생산되는 해조류를 이용하여 압출 성형물을 제조하기 위하여 단축스쿠류 압출성형기를 이용, corn grits에 미역 분말을 첨가하여 압출성형시켰을 때 일어나는 이화학적 특성변화를 반응표면 실험계획법에 의하여 분석하였다. 미역분말을 첨가한 corn grits압출성형물의 이화학적 측정치인 각 종속변수들간의 단순상관관계를 보면 밀도는 팽화율, 명암도, 파단강도는 수분용해 도지수, 명암도, 수분흡수지수는 수분용해도지수에서 유의차를 나타내었다. 독립변수인 수분함량(15∼21%), 미역분말함량(10∼30%) 및 토출구은도(95∼115℃)의 주어진 범위에서 각 종속변수인 이화학적 특성에 대한 영향을 3차원 반응표면 회귀분석을 하였을 때, 팽화율은 수분함량이 감소하고 토출구 온도가 증가할 때 증가하였으며, 밀도는 수분함량과 미역분말함량이 증가함에 따라 증가하는 것으로 나타났다. 파단강도는 수분함량과 미역분말함량이 증가함에 따라 증가하는 것으로 나타났다. 파단강도는 수분함량이 증가함에 따라 증가하는 반면, 미역분말함량에 따라서는 감소하는 경향이었다. 수분용해도지수는 수분함량이 증가할수록 증가하는 경향으로 나타났고, 명암도는 대체로 미역함량이 증가함에 따라 감소하는 경향을 보여주었다. The present study was focused on investigation of proper processing conditions to develop physicochemical properties of extrudates using sea mustard and corn by single extruder. Response surface analysis was used to evaluate effects of extrusion variables on the quality of the extrudates. Physicochemical dependence variables of sea mustard extrudates with corn grits show a significance correlation of within 5% . Among the various dependence variables, the expansion ratio showed a high correlation with bulk density, break strength, water solubility index and yellowness. Bulk density correlated closely with water solubility index; break strength with water absorption index and lightness, and water absorption index with lightness. Water solubility index and lightness showed a significance correlation with yellowness of within 0.5%. Three dimensional graphic analysis on response surface regression was conducted with each of the dependent variables which revealed statistically significant relationship to independent variables: 15∼21% moisture content, 10∼30% sea mustard content and 95∼115℃ die temperature. Expansion ratio decreased with increasing moisture and sea mustard content. It showed the highest value at 18 % moisture content, 10% sea mustard content and 95℃ die temperature. and the lowest value was at 21% moisture content, 30% sea mustard content and 105℃ die temperature. Bulk density was highest at 21% moisture content, 30% sea mustard content and 105℃ die temperature. On the other hand, it was lowest at 18% moisture content, 10% sea mustard content and 95℃ die temperature. Break strength was highest at 18% moisture content, 10% sea mustard content and 115℃ die temperature, but lowest at 21% moisture content, 30% sea mustard content and 105℃ die temperature. Water solubility index increased in the range of 43.9∼54.8 as the moisture content increased.

내후성강재의 철도용 강교량 적용기술

조광일(Kwang-Il Cho),성택룡(Taek-Ryong Seong),박용명(Yong Myung Park),권오혁(Oh-Hyuk Kwon),안기성(Ki-Sung An) 한국철도학회 2016 한국철도학회 학술발표대회논문집 Vol.2016 No.10

장지간 철도교에는 강교의 적용이 필수적이나 재도장이 필요한 단점을 가지고 있어, 재도장이 불필요한 내후성강이 강교에 적용되었다. 미국과 일본에서는 1960년대부터 강교량에 내후성강을 사용해왔고 현재에는 강교 적용 시 내후성강을 우선적으로 고려하고 있다. 반면, 국내에서는 1992년에 내후성강을 교량에 최초 적용한 후 도로교 약 30개소에 적용하였으나 철도교에는 적용사례가 없다. 이에 국내 교량 건설환경에 적합한 고강도 내후성강재로 HSB500W 및 HSB600W가 개발되었으며, 이의 사용을 위한 용접재료 및 이용기술이 개발되었다. 연구 결과, 내후성강 거더는 교량 적용에 필요한 성능을 모두 갖추었으며, 초기 제작비 약 5%, 100년 생애주기비용 약 30%를 절감할 수 있는 것으로 나타났다. Steel bridges usually applied for long-span railway bridges require repainting during those service life. To save the costs of repainting, weathering steels have been used for bridges since 1960s in the United States and Japan. Also, weathering steels have been having a priority when steels are considered as main material of bridges. On the other hand, there are few weathering steel bridges in Korea. In order to expand the application of weathering steels, the high-strength weathering steels HSB 500W and 600W were developed newly and those performances were evaluated. It was found that about 5% of the initial construction cost and about 30% of LCC for 100 years are reduced when the hybrid weathering steel bridge is applied.

Modeling of Inductively Coupled High Density Plasma Processes for the Fabrication of Semiconductor Devices

Jai Kwang Shin,Jae Joon Oh,Seong Gu Kim,Jae Seok Huh,Hyoung In Lee,Dong Gyu Kim,Tae Ryong Kim,Mark J. Kushner 한국진공학회 1999 한국진공학회 학술발표회초록집 Vol.- No.-