디지털 홀로그래피 단층 촬영

정현철,Jung, Hyunchul 한국비파괴검사학회 2014 한국비파괴검사학회지 Vol.27 No.2

시계열 프레임워크를 이용한 효율적인 클라우드서비스 품질·성능 관리 방법

정현철,서광규,Jung, Hyun Chul,Seo, Kwang-Kyu 한국반도체디스플레이기술학회 2021 반도체디스플레이기술학회지 Vol.20 No.2

Cloud service has the characteristic that it must be always available and that it must be able to respond immediately to user requests. This study suggests a method for constructing a proactive and autonomous quality and performance management system to meet these characteristics of cloud services. To this end, we identify quantitative measurement factors for cloud service quality and performance management, define a structure for applying a time series framework to cloud service application quality and performance management for proactive management, and then use big data and artificial intelligence for autonomous management. The flow of data processing and the configuration and flow of big data and artificial intelligence platforms were defined to combine intelligent technologies. In addition, the effectiveness was confirmed by applying it to the cloud service quality and performance management system through a case study. Using the methodology presented in this study, it is possible to improve the service management system that has been managed artificially and retrospectively through various convergence. However, since it requires the collection, processing, and processing of various types of data, it also has limitations in that data standardization must be prioritized in each technology and industry.

성견의 실험적 상피하 결합조직 이식시의 치주조직의 치유

정현철,최성호,조규성,채중규,김종관,Jung, Hyun-Chul,Choi, Seong-Ho,Cho, Kyoo-Sung,Chai, Jung-Kyi,Kim, Chong-Kwan 대한치주과학회 1997 Journal of Periodontal & Implant Science Vol.27 No.2

Several methods have been used for regeneration of tissue lost by periodontal disease. Subepithelial connective tissue graft technique, one of the technniques of mucogingival surgery, is used for the regeneration in esthetic problems such as recession, and denuded root coverage. This study is performed to evaluate the healing process and the regeneration and reattachment of periodontal tissue, including the reconstruction of junctional epithelium, and connective tissue. Alveolar defects in five adult dogs were treated with periodontal surgery and were attained by removing the marginal alveolar bone by $4{\time}3mm$ from CEJ in the labial side of incisors, and root surfaces were planed. The experimental sites were divided into two groups as follows. 1. root planing alone(control group) 2. with connective tissue graft (Experimental Group) In the two groups flaps were positioned and sutured tightly, the healing processes were observed and were histologically compared with each other after 2days, 4days, 1week, 2weeks, 4weeks. The results were obtained as follows : 1. In the two groups blood clots were observed as early as 2 and 4 days, and were resorbed at 1 week. 2. In the two groups moderate inflammation was observed as early as 2 and 4 days, decreased at 1 and 2 weeks, and disappeared at 4 weeks. 3. Junctional Epithelium migration was more significant in the control group, and was restrained by graft materials in the experimental group. 4. Features of connective tissue fiber attachment partially showed the parallel pattern in the two groups from 2 weeks, and entirely from 4weeks. 5. Anastomosis, between graft and connective tissue, appeared from 4 days in the experimental group and the border between them was not discriminated at 4weeks.

한의약의 변천과 갈등에 관한 연구

정현철,Jung, Hyun-Chul 대한한약협회 1998 大韓漢藥 Vol.2 No.-

폐주석산화물로부터 환원공정 및 전해정련을 통한 치과용 고순도 주석 회수

정현철,김상열,이민호,Jung, Hyun-Chol,Kim, Sang-Yeol,Lee, Min-Ho 한국자원리싸이클링학회 2018 資源 리싸이클링 Vol.27 No.6

In this study, using electro-refining process and methane gas reduction, we performed studying the recovery of tin with high purity from waste tin oxide had used as a electrode rod of ceramic furnace which occurred during glass production process. We recovered the crude tin of 99% purity from a methane gas reduction process and controlled a little amount of impurities. When the electrolytic refining condition was a current density of $60A/dm^2$ and the sulfuric acid concentration of 0.75 mol, 96.8% of recovered tin (99.979% of purity) were recovered during the electrolytic refining. We confirmed that toxic impurities such as Pb, Sb included in electrode rod. could be controlled.

호도약침(胡桃藥鍼)이 Glycerol로 유발(誘發)된 급성신부전(急性腎不全) 백서(白鼠)의 이뇨(利尿)에 미치는 영향(影響)

정현철,송춘호,Jung, Hyun-Chol,Song, Choon-Ho 대한침구의학회 2000 대한침구의학회지 Vol.17 No.1

This study was undertaken to determine if Juglandis Semen Aquacupuncture(Ja) has a protective effect against glycerol-induced acute renal failure in rats. Rats were dehydrated for 24hr and then injected with $5m{\ell}/kg$ of 50% glycerol, one-half of dose in each hindlimb muscle. In experiments for Ja effect, rats received $0.1m{\ell}$ of Ja extraction in both sides of corresponding $Sh{\grave{e}}ns{\bar{u}}$($BL_{23}$) of human body and non-acupuncture points(the root of tail) for 3 days after injection of glycerol. The experimental group were divided into the Normal group, the Control group, the Ja to $Sh{\grave{e}}ns{\bar{u}}$($BL_{23}$) group(Ja-AS), the Ja to non-acupuncture points group(Ja-AN). There were significant decrease of Urine vollume, total protein and phosphate level in Ja-AS as compared with the control group. There were not any significant change of Urine creatinine in Ja-AS as compared with the control group. There were significant decrease of Unine glucose in Ja-AS, Ja-AN as compared with the control group. This suggests that Ja-AS could be used in prevention and treatment of acute renal failure. However, the precise mechanisms of Ja protection remain to be determined.

고효율 실리콘 태양전지를 위한 lotus surface 구조의 형성

정현철,백용균,김효한,음정현,최균,김형태,장효식,Jung, Hyun-Chul,Paek, Yeong-Kyeun,Kim, Hyo-Han,Eum, Jung-Hyun,Choi, Kyoon,Kim, Hyung-Tae,Chang, Hyo-Sik 한국결정성장학회 2010 韓國結晶成長學會誌 Vol.20 No.1

단결정 실리콘 태양전지의 광학적 손실을 감소시키는 표면 텍스쳐링은 최종 셀의 효율을 향상시키기 위하여 매우 중요하다. 본 연구에서는 2-step texturing의 공정으로 기존의 텍스쳐링에서 이루어진 피라미드에 수 많은 sub-micrometer 사이즈의 구조를 형성시켰다. $AgNO_3$ 용액으로 웨이퍼 표면에 Ag코팅을 한 후, 그 웨이퍼를 다시 HF/$H_2O_2$ 용액으로 수십초 동안 식각을 거치게 된다. 결과적으로, 피라미드 위에 생성된 수 nm사이즈의 구조물들은 $AgNO_3$의 농도 및 식각 시간의 변화에 의해 그 크기와 굵기가 변화하는 것을 알 수 있었다. 웨이퍼의 표면이 2-step texturing에 의해 식각이 이루어지면 연잎의 거친 표면과 비슷해지고, 그 결과 평균 10% 이상의 반사율을 보이던 기존 웨이퍼에서 3% 이하의 낮은 반사율을 얻을 수 있었다. 이는 일반적인 텍스쳐링과 anti-reflection coating을 거친 웨이퍼의 반사율보다 낮은 결과이다. The reduction of optical losses in mono-crystalline silicon solar cell by surface texturing is a critical step to improve the overall cell efficiency. In this study, we have changed the sub-micrometer structure on the micrometer pyramidal structure by 2-step texturing. The Ag particles were coated on the micrometer pyramid surface in $AgNO_3$ solution, and then the etching with hydrogen fluoride and hydrogen peroxide created even smaller nano-pyramids in these pyramids. As a result, we observed that the changes of size and thickness of nano structure on pyramidal surface were determined by $AgNO_3$ concentration and etching time. Using 2-step texturing, the surface of wafers is etched to resemble the rough surface of a lotus leaf. Lotus surface can reduce average reflectance from 10% to below 3%. This reflectance is less than conventional textured wafer including anti-reflection coating.

정석해의 자유 이념과 역사성

정현철(Jung, Hyun Chul) 역사실학회 2018 역사와실학 Vol.66 No.-

정석해의 사상은 두 가지 점에서 중요한 가치를 가진다. 우선 무엇보다 그의 사상은 역사적 사건들 곧 우리의 근대로의 이행 과정에서 발생한 사건들과 직접 접촉하면서 형성되어서 말 그대로의 생생한 현장성과 시대적 요청을 담고 있다. 또한 그는 그 사건들 속에서 관망하거나 혹은 기득권에 영합하거나 하지 않고 그것을 실천에 부합하게 비판적으로 성찰해 냄으로써 우리에게 시대정신을 제시하고 있다. 곧, 정석해의 사상은 생생한 살아 있는 정신이 수행한 시대를 거스르는 소위 ‘반시대적 고찰’이라 할 수 있다. 이러한 기본 인식을 바탕으로 필자는 우선 정석해의 사상을 각인하고 있는 시대적 소명이 무엇이었는지 살펴보고자 한다. 그것은 일차적으로는 일본 제국주의로부터의 해방이라고 볼 수 있고 궁극적으로는 근대로의 이행 과정에서의 민주주의의 실현이라고 할 수 있다. 그리고 필자는 이와 같이 민주주의를 좆는 그의 사상이 그것의 이념의 편에서는 자유를 그 중심에 세우고 있다는 점을 밝히고자 한다. 이를 위해 자유의 이념을 그의 사상 속에서 다각적으로 살펴볼 것이다. 마지막으로 그는 이같은 이념에 철학적 근거를 마련하기 위해 어떠한 이론 요소들을 도입하고 긍정하는지 살펴 볼 것이다. 실제로 그의 사상은 다양한 이론 전통에 관여하고 있어 여러 요소들의 조합을 통해 구조화되어 있다. Jung Suk Hae`s idea has important value in two respects. First of all, his ideas are formed in direct contact with the historical events, the events that took place in the process of our transition to modernity, and contain literally vivid field and period demands. He is also presenting the spirit of the times to us by critically reflecting on it in accordance with the practice, without observing in the events or meddling in vested interests. In short, Jeong Seon Hae`s idea can be said to be a so - called` anti - historical view` that goes against the era of vivid living spirit. Based on this basic awareness, let me first examine what was the call of the times to imprint the idea of Jeong Seok Hae. It can be seen as a liberation from Japanese imperialism in the first place, and ultimately the realization of democracy in the process of transition to modernity. And I want to show that his idea of democracy like this is centered on freedom on the part of its ideology. To this end, I will examine the idea of freedom in his thought in various ways. Finally, he will examine what theories are and will adopt in order to establish a philosophical basis for such ideology. In fact, his ideas are involved in various theoretical traditions and are structured through a combination of elements.

온도에 따른 시트상 이종계면 공간전하 분포

정현철(Hyun-Cheol Jung),김형규(Hyeung-Gyu Kim),황보승(Hwangbo Seung) 대한전기학회 2019 대한전기학회 학술대회 논문집 Vol.2019 No.7

분할 특징 추출에 의한 양식 문서의 분류

정현철(Hyunchul Jung),이종현(Jonghyon Yi),최영우(Yeongwoo Choi),김재희(Jaihie Kim) 대한전자공학회 1999 대한전자공학회 학술대회 Vol.1999 No.6