샌드블라스팅에 의한 도재의 표면처리가 브라켓의 전단결합강도에 미치는 영향

장원주,김상철 원광대학교 생체재료·매식연구소 1999 원광생체재료·매식 Vol.8 No.1

The purpose of this study was to evaluate the effect of sandblasting treatment on porcelain, on shear bond strength or bracket. This study was carried out with 192 samples which were divided into 24 groups according to 3 bonding agents and 8 surface treatment methods. Bonding agents were Ortho-oneTM, Transbond XTTM, Fuji Ortho LCTM, and surface treatment methods were differentiated by concentrations of etching agent, and use of silane or sandblasting. After surface treatment, porcelains was bonded with standard edgewise brackets and were stored in 37℃ saline for 24 hours. A universal testing machine was used to measure the shear bond strength of bracket to porcelain. The results were as follows : 1. The group which was treated with sandblasting or silane showed higher shear bond strength than the group which was treated with etching only. And the group which was treated with sandblasting, etching and silane showed the most highest shear bond strength(9.1-10.8 MPa). 2. No significant differences were found among bonding agents or concentrations of etching agent.

3차원 전극(Bipolar Packed Bed Electrode)을 이용한 호소수 처리(II)

장철현,박상우,최창수 한국환경과학회 2002 한국환경과학회지 Vol.11 No.4

This study was to analyze the right or wrong of gray-water treatment by applying BPBE electrode cell to the effluence water in the terminal disposal plant of sewage. The results were as follows : The best result was obtained with applied voltage 40V and detention time 6 minutes for the BPBE electrode cell which has the graphite-plate in main electro-de, packing coconut activated carbon. The elimination rate of COD of Al-plate was higher than that of graphite-plate in main electrode. The result of electrolysis for 3 hour in parallel circuit showed the using possibility of gray-water according to each elimination rate : COD 59%, T-N 69 %, T-P 69%. The BPBE electrode cell with the Al-plate in main electrode made the best effect for the elimination of algae in lake water and algae were not occurred in electrolytic water.

요로결석 환자에서 Pethidine, Nalbuphine, Ketorolac의 진통효과 비교

장석준,박인철,정성필,최성욱,이한식 대한응급의학회 1996 대한응급의학회지 Vol.7 No.2

Ureter stone cause severe flank and abdominal pain. In emergency room, these patients require rapid pain relief and diagnosis. Therefore, authors have conducted a study on the efficacy of three types of commonly used analgesics including non opioid analgesics; intramuscular ketorolac 30mg and nalbuphine 10mg was compared with pethidine 50mg in 74 patients who visited SEVERANCE hospital emergency care center with complaint of flank colicky pain from Jan1. 1996 to Mar 31. 1996. Pain was assessed before the drug administration, and then at 10min, 20min, 30min time interval after the first dose. Visual analogue scale was used to assess the pain intensity and scale was self drawn by each patient during the time of pain assessment. Additional need of rescue analgesia and adverse effecfs of first-line analgesia was also recorded. Statistical significant was confirmed using ANOVA and Chi square test. The difference in the decrease of pain intensity was not significant among the three analgesics(P=0.65). Rescue anagesia was required in 37.1% of pethidine, 42.8% of nalbuphine, 16.6% of ketorolac and totally 33.8%. The incidence of all types of adverse event of pethidine, nalbuphine and ketorolac were 14.2%, 14.2% and 5.5% in respectively. The results of this study have shown that non opioid analgesics are as effective as opioid analgesia. Therefore, non opioid analgesics can be tried first line of pain relief drug of renal coliky pain with minimal adverse effects.

무주거자의 실태와 보호방안에 관한 정책적 고찰 : 대구지역 Street Homeless를 중심으로 Focused on Daegu Area

성도경,장철영 영남대학교 지역발전연구소 2003 영남지역발전연구 Vol.31 No.-

본 연구의 목적은 거리 무주거자들의 실태와 그 보호방안에 관해서 살펴보고자 하는데 있다. 거리 무주거자(street homeless)는 쉼터 무주거자(shelter homeless)와는 다른 어떤 사회적 특성을 가지고 있어서, 이들에 대한 보호정책도 쉼터 무주거자와는 서로 다른 양상을 띠어야 한다. 그러나, 지금까지 거리 무주거자들에 대한 보호정책을 살펴보면 이들을 단지 쉼터로 유인하여 보호하고 자활프로그램 방법을 통하여 해결하고자 하는데 있었다. 그러나, 거리 무주거자가 여전히 사회에 존재하고 있다는 사실에 주목할 필요가 있다. 또한, 거리 무주거자는 쉼터 무주거자와 비교해 볼 때 더욱더 극단적인 생활환경과 빈곤 속에서 존재하고 있으며, 이들에 대한 파행성과 사회의 관계망 또한 상당히 열악하다고 할 수 있다. 따라서, 거리 무주거자에 대한 보호 정책은 쉼터 무주거자와는 다른 양상을 띠어야만 한다. 이들에 대한 보호정책방안으로는 첫째, 거리 무주거자를 위한 응급 보호센터의 구축이 필요하며, 둘째, 공식적 사회보장과 사회복지 서비스 체계에서 이들이 배제되지 않도록 하여야 한다. 셋째, 거리 무주거자들이 보호사업 추진시 이들에 대한 유연하고 융통성 있는 정책적 고려가 요구된다.

지식자산의 측정과 보고 : 스칸디아(Scandia)의 사례

張志仁,申相哲 中央大學校 經營硏究所 1999 經營學論集 Vol.26 No.1

3포트 ER 밸브 개발을 위한 분산계 ER유체의 유동특성에 관한 연구

장문제,장성철,염만오,이동극,김기홍 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

The purpose of the present study is to examine the flow characteristics of ER fluids between 2 port and 3 port rectangular tube brass electrodes. ER fluid is made silicon oil mixed with 2-3wt% starch having hydrous particles. Flow visualization of the ER fluids were obtained by CCD camera measuring those of the clusters using an image processing technique. This research found the flow rate(Q_(L)) with 0 kV/mm, 0.5kV/mm and 1.0kV/mm for Q_(L) = 0, 0 and 5.73cm³/s. When the strength of the electric field increased, the cluster of ER fluids are clearly strong along the rectangular tube and the flow rate(Q) decreased.

낙동강 하구에서의 해수유동

장성태,김기철 東亞大學校 海洋資源硏究所 1997 硏究論文集 Vol.10 No.1

Nakdong Estuary is complex water system, where salt and fresh water meet each other. The circulation in Nakdong Estuary is affected by the factors such as the mixing of salt and fresh water, the amount of river discharge, wind, bottom topography, waves and Coriolis force. The flow pattern and mixing processes are analysed using the data obtained from the surveys in which the river plume is tracked using drogue, salinities are measured along the section from Dadae-Dong to Gaduk Island and serial time series measurements of current are conducted. Several features in physical oceanographic environments are found which seems to be caused by the management of the Nakdong River barrier. Nakdong River plume is not continuous but patch-like because river water is discharged intermittently from the barrier according to the tidal cycle. The effect of the river plume on the flow pattern near the Nakdong River barrier is somewhat stonger than the tidal current.

淨水場 슬러지의 堆肥化에 關한 硏究

張哲鉉,朴相雨 한밭대학교 산업과학기술연구소 1995 논문집 Vol.3 No.-

This study analyzed temperature, pH, electric conductivity, moisture contents and organic materials for composting which mixed bulking agents and composting necessaring additional materials a discharged sludge in water treatment plant. 1. Temperature was sustained at 55-65℃, highly at the water purifier sludge rate of 30%. 2. pH was neared neutral as passed the composting time. 3. The electric conductivity of organic materials compost was decleased to increasing of the composting time. 4. The content of moisture was showned from 20 to 30%. 5. The percentage of organic materials in compost was decreased to the composting time.

ERF와 산업용 콘트롤러를 이용한 FHA의 제어특성에 관한 연구

장성철 한국공작기계학회 2005 한국생산제조학회지 Vol.14 No.1

Making the best use of the features of the electro-rheological(ER) valve, a two-port pressure control valve using ER fluids is proposed and manufactured. The ER Valve characteristics are evaluated by changing the intensity of the electric field and the number of electrode. In addition, the performance of the plate type ER Valve is investigated by change the particle concentration of the ER fluid. As only with electrical signal change to the ER Valve in which ER fluid flowing, ER fluid flow is controlled, so development of simple ER-Valves have been tried. The ER-Valves and pressure drop check method are considered to be applied to the fluid power control system. Using the manufactured pressure control valve, a one-link manipulator with FHA in robot system is driven. As a result, it is experimentally confirmed that the pressure control valve using ER fluids is applicable to use in driving actuator. If it applies characteristics of the ER fluids, it will be able to apply in the control system for the ER Valve which occurs from industrial controller(PLC).

컴퓨터 비젼 방법을 이용한 3차원 물체 위치 결정에 관한 연구

장완식,김경석,이성민,주철,김재확,김대현 한국공작기계학회 1999 한국생산제조학회지 Vol.8 No.6

This study shows an alternative method for the determination of object's position, based on a computer vision method. This approach develops the vision system model to define the reciprocal relationship between the 3-D real space and 2-D image plane. The developed model involves the bilinear six-view parameters, which is estimated using the relationship between the camera space location and real coordinates of known position. Based on the estimated parameters in independent cameras, the position of unknown object is accomplished using as sequential estimation scheme that permits data of unknown points in each of the 2-D image plane of cameras. This vision control method is the robust and reliable, which overcomes the difficulties of the conventional research such as precise calibration of the vision sensor, exact kinematic modeling of the robot, and correct knowledge of the relative positions and orientation of the robot and CCD camera. Finally, the developed vision control method is tested experimentally by performing determination of object position is the space using computer vision system. These results show the presented method is precise and compatible.