DOE를 적용한 카메라폰 모듈용 비구면 Glass 렌즈의 가압성형조건 연구

김혜정,차두환,이준기,김상석,김정호,Kim, Hye-Jeong,Cha, Du-Hwan,Lee, Jun-Key,Kim, Sang-Suk,Kim, Jeong-Ho 한국전기전자재료학회 2007 전기전자재료학회논문지 Vol.20 No.8

This study investigated the pressing conditions in the molding of aspheric glass lenses for the mega pixel phone camera module using the DOE method. Tungsten carbide (WC; Japan, Everloy Co., 002K),which contained 0.5 w% cobalt (Co), was used to build the mold. The mold surface was ultra-precision ground and polished, and its form accuracy (PV) was 0.85um in aspheric surface. We selected four factors, pressing temperature, force and time of first step, and force of second step, respectively, as the parameters of the pressing process. in order to reduce the number of experiments, we applied fractional factorial design considering the main effects and two-way interactions. The analysis results indicate that the only two main effects, the pressing temperature and the time of pressing step 1, are available for the form accuracy (PV) of the molded lens. The analysis results indicated that the best combination of the factors for lowering the form accuracy(PV) value of molded lens was to have them at their low levels.

탄소층으로 캡슐화된 Ni나노입자 촉매의 CO₂ 메탄화 반응

김혜정,김승보,김동현,윤재랑,김민재,전상구,이경자,이규복,Kim, Hye Jeong,Kim, Seung Bo,Kim, Dong Hyun,Youn, Jae-Rang,Kim, Min-Jae,Jeon, Sang Goo,Lee, Gyoung-Ja,Lee, Kyubock 한국재료학회 2021 한국재료학회지 Vol.31 No.9

Carbon-encapsulated Ni catalysts are synthesized by an electrical explosion of wires (EEW) method and applied for CO₂ methanation. We find that the presence of carbon shell on Ni nanoparticles as catalyst can positively affect CO₂ methanation reaction. Ni@5C that is produced under 5 % CH₄ partial pressure in Ar gas has highest conversions of 68 % at 350 ℃ and 70 % at 400 ℃, which are 73 and 75 % of the thermodynamic equilibrium conversion, respectively. The catalyst of Ni@10C with thicker carbon layer shows much reduced activity. The EEW-produced Ni catalysts with low specific surface area outperform Ni catalysts with high surface area synthesized by solution-based precipitation methods. Our finding in this study shows the possibility of utilizing carbon-encapsulated metal catalysts for heterogeneous catalysis reaction including CO₂ methanation. Furthermore, EEW, which is a highly promising method for massive production of metal nanoparticles, can be applied for various catalysis system, requiring scaled-up synthesis of catalysts.

시뮬레이션을 활용한 폰카메라 렌즈모듈 부품용 사출금형개발

김혜정,김재훈,김영규,송준엽,문덕희,Kim, Hye Jeong,Kim, Jae Hoon,Kim, Yeong Gyoo,Song, Jun Yeob,Moon, Dug Hee 한국시뮬레이션학회 2013 한국시뮬레이션학회 논문지 Vol.22 No.4

휴대폰 시장의 확산으로 인하여 휴대폰에 장착되는 카메라 렌즈모듈의 수요도 급증하고 있다. 렌즈모듈 부품의 경우 해상도의 증가에 따른 사출공정의 품질보증과 원가절감이라는 두 가지 목표를 달성해야 한다. 따라서 본 논문에서는 더블카세트 방식의 금형구조를 이용하여 경통과 쉴드 두 종류의 제품을 개발하기 위해 시뮬레이션을 활용한 사례를 소개한다. 개발과정에서 두 종류의 시뮬레이션 기술을 활용하였는데, 첫 번째는 금형 설계단계에서 사출품의 성형성을 분석하기 위한 시뮬레이션(일명 Computer Aided Engineering)을 Mold Flow$^{TM}$를 사용하여 수행하였고, 두 번째는 사출기에 금형을 장착한 후 제품이 사출되어 취출하는 동작을 분석하기 위한 동작 시뮬레이션을 DPM Assembly$^{TM}$를 이용하여 수행하였다. 개발 결과 기존 방식에 비해 제품의 생산성이 300% 이상 증가하는 효과를 얻었다. The demand of a camera-lens-module which is installed in mobile phone has been increased explosively as the increase of mobile phone market. Recently, two missions are given to the parts manufacturer of lens module, and they are how to keep the quality of injection moulding process as the increase of resolution, and how to decrease manufacturing cost. In this paper, a simulation study is introduced which is used for developing barrel and shield considering the double-cassette type of mould. At first, the simulation for injection process using Mold Flow$^{TM}$ is applied in the phase of mould design, and mechanical simulation using DPM Assembly$^{TM}$ is applied for collision detection between picking robot and mould. As a result, the productivity increased more than 300%.

COVID-19로 인한 대학교 원격 화상강의 유형에 따른 학업 성취도에 대한 연구

김혜정,Kim, Hye-Jeong 국제문화기술진흥원 2021 The Journal of the Convergence on Culture Technolo Vol.7 No.3

본 연구는 코로나 바이러스로 인해 본격적으로 활용되고 있는 원격 화상강의 유형이 학습자들의 학업 성취도에 미치는 영향을 파악하고자 하였다. 화상강의 유형은 일반적 강의 중심형과 조별과업 중심형 두 가지로 구분하였다. 두 가지 화상강의 유형에 맞게 실험반과 비교반을 설정하였고 두 가지 유형에 따른 학업 성취도의 차이를 파악하기 위해 성취도 테스트와 설문조사가 실시되었다. 성취도 테스트 결과 화상강의 유형에 따른 두 집단 간의 성취도 점수는 유의미하지 않은 것으로 나타났다. 화상강의 만족도에 대한 설문 조사 결과 두 집단의 만족도는 모두 높은 것으로 나타났다. 일반 강의 형식으로 진행된 반에서 화상강의에 만족하는 이유로는 학습 효과, 교수자의 수업 준비 및 태도, 수업 참여 촉진이 그 이유로 나왔다. 조별 과업 중심으로 진행된 반에서는 소통과 공유 가능, 조별 토론의 효율성, 조별 과업의 부담 없는 난이도 등이 화상강의에 만족하는 이유로 제시되었다. 언택트 시대 화상강의는 점차 일반화되어 가고 있고 이것의 효율성을 극대화할 수 있는 다양한 교수 전략이 개발되어야 할 것이다. This study examined how different types of remote video lectures, which universities are using in earnest now due to the COVID-19 pandemic, impact the academic achievement of learners. Zoom-based remote video lectures were divided into two types-general lecture-centered and group task-oriented-and experimental and control groups were set up accordingly. An achievement test and a questionnaire were conducted to determine how academic achievement differed between these two approaches. The achievement test revealed no significant differences in achievement scores between the two groups. Meanwhile, the questionnaire regarding satisfaction with Zoom-based video lectures indicated that both groups were highly satisfied. Participants in the general lecture-centered type group cited the effect of learning, their instructors' class preparation and attitudes towards the class, and the promotion of participation in learning activities as the causes of their satisfaction, while participants in the task-oriented type group highlighted communication and sharing, the efficiency of group discussions, and the moderate difficulty level of group tasks as the reasons for their satisfaction with the video lectures. Remote video lectures in the untact era are becoming increasingly common, and educators will need to develop various Zoom-based teaching strategies to maximize their efficiency.

근관 내 File의 파절 시 대처 방안

김혜정,장훈상,박세희,조경모,김진우,Kim, Hye-Jeong,Jang, Hoon-Sang,Park, Se-Hee,Cho, Kyung-Mo,Kim, Jin-Woo 대한치과보존학회 2006 Restorative Dentistry & Endodontics Vol.31 No.3

근관형성을 하는 과정에서 기구가 파절될 가능성은 언제나 존재한다. File을 비롯하여 lentulo spiral, Gates-Glidden (GG) bur 또는 여타의 이물질도 근관 내에 남겨질 수 있다. 근래에는 수동 file에 비해 많은 장점을 가지고 있는 회전식 nickel-titanium (NiTi) file의 사용이 보편화 되고 있으나 기구의 높은 파절 경향이 문제가 되고 있다. NiTi file의 파절은 매우 빠른 시간내에 일어나고 예측이 불가능하며 임상가에게 정신적 stress를 가져다. 주기 때문에 임상가로 하여금 niTi file의 사용을 주저하게 만들기도 한다. 근관 내 기구가 파절되면 제거하는 것이 가장 최선의 해결 방법이다. 초음파 기기와 미세 현미경의 사용으로 파절된 기구의 제거율이 높아지고 있지만 제거하는 것이 쉬운 일만은 아니며 항상 제거가 가능한 것도 아니다. 그러므로 예방이 최선의 방법이라 할 수 있다. 본 증례에서는 근관 내 file이 파절된 경우에 있어 여러 가지 대처 방안에 대해 보고하고자 한다. During root canal preparation procedures, the potential for instrument separation is always present. Files, a lentulo, a Gates-Glidden (GG) bur or any manufactured obstruction can be left behind in the canal Nickel-titanium (NiTi) rotary files are in common usage in these days. Despite their undeniable advantages, there is a potential risk of separation within the canals. It is very rapid, unpredictable, and creates a great deal of stress for the practitioner. When an endodontic instrument separates, the best option is to remove it. Ultrasonic instruments and microscopes have improved the success rate for removing separated instruments. But It is difficult and not always possible. Therefore prevention is the key. In this case report, several management methods of separated file in the canal are presented.

鼻流淸涕症에 關한 文獻的 考察

김혜정,채병윤,Kim, Hye-Jeong,Chae, Byeong-Yun 대한한방안이비인후피부과학회 1989 한방안이비인후피부과학회지 Vol.2 No.1

Evaluation of time-dependent antimicrobial effect of sodium dichloroisocyanurate (NaDCC) on Enterococcus faecalis in the root canal

김혜정,박세희,조경모,김진우,Kim, Hye-Jeong,Park, Se-Hee,Cho, Kyung-Mo,Kim, Jin-Woo The Korean Academy of Conservative Dentistry 2007 Restorative Dentistry & Endodontics Vol.32 No.2

이염화이소시아뉼산나트륨 (NaDCC)은 염소 화합물의 일종으로 차아염소산나트륨 (NaOCl)과 비교 시 동일한 농도의 용액에서 같은 염소 이온을 가지고 있으며 비슷한 정도의 항균력을 가진다고 알려져 있다 이 연구의 목적은 이염화이소시아뉼산나트륨 근관 내 사용 시 시간에 따른 항균성을 평가하고 이를 현재 근관세척제로 사용되고 있는 차아염소산나트륨 및 클로르헥시딘 (CHX)과 비교하고자 하였다. E. faecalis에 대한 세 가지 제재의 최소증식억제 농도 (MIC)를 실험한 결과 NaOCl과 NaDCC에서는 0.125%를 보였고 CHX에서는 0.063%로 나타났다. 근관 내 사용에 대한 실험은 최근에 발거된 128개의 단근치를 사용하였으며 치경부와 치근단 부위를 절단하여 10 mm 길이를 가지는 시편을 만들었다. 시편의 내경은 #3 Gates-Glidden drill을 이용하여 동일하게 하였다. 각각의 치아 시편의 근관 내에 E. faecalis를 접종하고 3일간 배양한 후 40개씩 3개의 군으로 분류하고 대조군으로 8개의 시편을 이용하였다. 실험군 1, 2, 3은 각각 NaDCC, NaOCl, CHX으로 근관세척하였고 대조군은 멸균된 식염수를 이용하였다. 각 군은 다시 12시간, 24시간, 72시간, 7일의 시간에 따라 4개의 하위 군으로 분류하였다. 정해진 시간이 지난 후 멸균된 paper point를 이용하여 근관 내용물을 채취하고 BHI agar plate로 옮겨 배양하였다. 그 후 #4, 5GG drill을 이용하여 근관 내면을 삭제하고 이 때 생겨나는 상아질을 멸균된 증류수가 들어있는 시험관에 넣었다. 이것을 희석하여 BHI agar plate로 옮겨 배양하였다. 24시간이 지난 후 bacterial CFU를 측정하였다. 실험 결과 모든 실험군에서 bacterial CFU가 관찰되지 않았고 E. faecalis에 대한 세 가지 제재 모두 비슷한 항균 효과를 보였다. 멸균된 식염수를 이용한 대조군에서는 모두 bacterial CFU가 존재하였다. NaDCC를 근관세척제로 사용할 경우 1주 이내의 시간 동안에는 적절한 항균효과를 유지 할 수 있을 것이라 생각되며 임상에 적용하기 위해서는 조직 용해도를 비롯한 치근단 조직에 대한 직접적인 영향 등의 평가가 더 이루어져야 할 것으로 생각된다. The purpose of this study was to assess the antibacterial effect of sodium dichloroisocyanurate (NaDCC), sodium hypochlorite (NaOCl), and chlorhexidine (CHX) on Enterococcus faecalis and to evaluate and to compare the time-dependant antimicrobial effect of NaDCC with NaOCl and CHX in the root canal in vitro before and after instrumentation. Extracted Human single teeth were prepared by serial instrumentation technique. The samples were autoclaved and contaminated for 3 days with E. faecalis monocultures. The teeth were then divided into 4 groups Each group was irrigated and inserted with 2% NaOCl, 2% NaDCC, 2% CHX and steri)ized saline. After 6, 12, 24, 72h, and 1 week incubation, sterilized paper point was inserted into the root canal. Paper points containing root canal contents were then placed on the agar plate. And then each root cana) was prepared with #4 and #5 GG (Gates-Glidden) drill. The debris were collected in the sterilized microtube and the plates were incubated at $37^{\circ}C$ in an increased $CO_2$ atmosphere. After 24h incubation the growth of bacteria around the paper points were measured. NaOCl and NaDCC solution shows similar antimicrobial effect for E. faecalis at 6, 12, 24, 72h and 1 week. In centrol group, irrigated with sterilized saline, no antimicrobial effect was observed. The results are in agreement with other investigators, who have shown the bactericidal property and possibility of NaDCC as a root canal irrigation solution. Thus it seems that NaDCC solutions can be clinically applied into the root canal within 1 week after dilution.

만성두드러기에 대한 임상적 고찰

김혜정,Kim, Hye-Jeong 대한한방안이비인후피부과학회 2002 한방안이비인후피부과학회지 Vol.15 No.2

Introduction Urticaria is widely spread disease. About 15-20 $\%$ of population has experienced at least once in a life time. The etiology of urticaria is uncertain till now, and the affcting factors are various chemical material, physical factors, alcohol, fever, exercise, and hormone, etc. The symptoms of urticaria are small or large wheal-erythema reaction and itching or tingling sense. Cause there is no probe to detect the urticaria clearly, the treatment of urticaria is symptomatic. And mostly urticaria can be chronic and very hard to treat it fundamentally. Nowadays, many trials to treat the urticaria in oriental medical way show good curability. In this paper I'd like to report the treatment rate and degree of urticaria patients mostly using anti-histamine medication. Subjects From the outpatients who visited Korean Hospital of Kyunghee Kangnam during 2000-4 and 2002-1, the 36 chronic urticaria patients, at least more than 4 weeks from onset and 2weeks of treatment period, were chosen. Methods I evaluated the results of treatment with the following scale. Very Good: The all symptoms are clearly disappeared or one third of symptoms remain and sometimes eruption is appeared. Good: Half of the symptoms are improved but most of symptoms remain. No Change: No change appears before and after treatment. Worse: The degree and duration of eruption get worse than pre-treatment state. Results For Acupuncture treatment, I chose the several Acu points like Hapgok(합곡), Taichung(대충), Gokji(곡지), Yanggok(양곡), Yanggea(양계), and lmeup(족임읍), and usually lasted it 15 minutes. With the acupuncture treatment and herb medicine, 2-3 times a week, the patients whose treatment period was 2 to 4 weeks were 17(47.2$\%$), 4 to 8 weeks were 11(30.5$\%$), 8 to 12 weeks were 3(8.3$\%$), 12 to 16 weeks were 3(8.3$\%$), longer than 16 weeks were 2(5.5$\%$) Collecting the statistics of the frequency of prescripted herb medicine, Hyangsosan(향소산) was prescripted 21 times(58.3$\%$), Hyangsapyungwisan(향사평위산) was 15 times(41.6$\%$), Hwapisan(화피산) was 9 times(25$\%$), Yangwitang(양위탕) was 6 times(16.6$\%$), Bojungikkitang(보중익기탕가미) was 4 times(11.1$\%$), Yongdamsagantang (용담사간탕가미) was 4 times(11.1$\%$). The result of the treatments, evaluating with mentioned rate scale, was 11 cases(30.5$\%$) were Very Good degree, 19 cases(52.7$\%$) were Good , 6 cases(16.6$\%$) were No Change. No cases were Worse degree. Conclusion According to this research, we could say that chronic urticaria can be treated with Oriental medical methods. But more precise probes in both Oriental and Western medicine to diagnose the chronic urticaria should be established and we need to make standards for testing and diagnosing the chronic urticaria.

두드러기에 關한 臨床的 考察

김혜정,채병윤,Kim, Hae-Jung,Chae, Bhung-Yoon 대한한방안이비인후피부과학회 1997 한방안이비인후피부과학회지 Vol.10 No.1

Urticaria is an erythematous or white non-pitting edematous plague that changes in size and shape by peripheral extention or regression during the few hours or days. Urticaria is classified as acute or chronic type. The etiology of acute urticaria has been determined in many case, but the cause of chronic urticaria has been determined in only $5\%\;to\;20\%$ of cases. This observation was aimed to evaluate the clinical manifestations and clinical indence of urticaria seen between June, 1995 and November, 1996(18months) at the Department of Dermatology, Oriental Medical Hospital, Kyung Hee University. The results were summarized as follows ; 1. In the cases of 106 patients, $43\%\;were\;male\;and\;51\%$ were female. 2. The pick incidence of age group was 20 to 29($32\%$). 3. The most frequent duration of urticaria was from 2 months to 6 months. 4. In this study, the inciting causes could not be found in $61\%\;of\;acute\;patients,\;60\%$ of chronic patients. 5. Among 107 patients, $5\%$ of all patients had personal history of atopic diseases and $9\%$ of all patients had familly history. 6. Angioedema was founded in 7 patients, and the most common involved site were lips, eyelids and tongue. 7. The most frequently treated prescription was Chhunggisan which occupied $51\%$ of all, Gyakhangjunggisan(41\%$) and Gosamhomasan($25\%$), Bangpoongtongsungsan($22\%$) in that order of frequency.

나눔으로 고객과 하나되는 KIHA - 취약계층의 건강을 책임지는 창원산업보건센터

김혜정,Kim, Hye-Jeong 대한산업보건협회 2019 산업보건 Vol.372 No.-