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%.

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.

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.

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.

脫毛에 對한 臨床的 考察

김혜정,채병윤,Kim, Hae-Jung,Chae, Byung-Yoon 大韓外官科學會 1996 大韓外官科學會誌 Vol.9 No.1

The alopecia is classified to Alopecia areata, Telogen effluvium, Anagen effluvium and Androgenetic alopecia. The exact cause of alopecia is not known, but a inherent and immunologic anc psychosomatic and endocrinic factors are suspected. We analysed clinical study in 77 patients, who had visited to the Dept. of Dermatology, Hospital of Oriental Medicine, Kyung Hee University to treat alopecia from June, 1994 to March, 1995. The results were summarized as follows; 1. In the series of 77 patients, $52\%\;were\;male\;and\;48\%$ were female. The peak incidence of age group was 20 to 29 ($55\%$). 2. The peak incidence of age group at on set was 20 to 29 ($49\%$). 3. The most frequent feature was insomnia ($25\%$). Frequent appeared signs and symptoms in descending order were head itching, head scale, fatigue and dizziness. 4. The personal history of patient were seborrheic dermatitis ($17\%$), atopic dermatitis, disorder of thyroid gland and acne in descending order. 5. The patients with family history occupied $25\%$. 6. Shineung Yangjin Dan was most used in treatments as $36\%$.

結節 紅斑에 對한 文獻的 考察

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

Erythema nodosum is a nodular erythematous eruption usually limited to the low extremities. Erythema nodosum seems to be Gwadungjun(瓜藤纏) and Damp-heat flow(濕毒流注) in oriental medicine. The symptom of erythema nodosum is similar to that of Gwadungjun, so we investigated the literatures of oriental medicine and recet medicine. The results were summarized as follows; 1. In Oriental medicine, erythema nodosum regarded as Damp-heat flow and Gwadungjun. 2. Inflammatory nodus of lower extremity, ie, similar to Gwadungjun, Damp-heat flow, Bichonbal(비천發), Samnibal(三里發), Ududok(魚두毒), etc. 3. Erythema nodosum results from inner damp-heat(內有濕熱), affection due to pathogenic wind(外感風邪). 4. Treatment is to clear away heat(淸熱), remove dampness(利濕), heat from blood(凉血), cold-damp(祛寒), and promote blood flood(活血通絡). 5. We can use Bangpungtongsungsan(防風通聖散), Sopunghwa1hyultang(疏風活血湯), and Danguijumtongtang(當歸拈通湯), etc.

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.

굴삭기 부품 용접 자동화라인의 셀생산방식 적용을 위한 시뮬레이션 연구

김혜정,이승우,문덕희,Kim, Hye Jeong,Lee, Seung Woo,Moon, Dug Hee 한국시뮬레이션학회 2013 한국시뮬레이션학회 논문지 Vol.22 No.2

다품종 소량생산이 보편화 되면서 하나의 생산라인에서 여러 종류의 제품을 교대로 생산하는 혼류생산방식이 보편화 되었다. 하지만 흐름라인 방식의 혼류생산에서는 필연적으로 작업장 간의 공정시간 불균형이 존재한다. 따라서 이러한 공정불균형에 의한 대기의 낭비를 최소화하기 위하여 기존의 흐름생산방식에서 셀생산방식으로 전환하는 시도가 빈번하게 발생한다. 본 논문에서는 굴삭기 부품을 생산하는 혼류흐름라인 방식의 자동화 로봇 용접라인을 FMC 개념의 직선형 셀방식으로 전환하는 과정에서 타당성 검토를 위해 시뮬레이션을 수행한 사례연구 결과를 소개한다. 분석결과 26.7%의 생산량 증가와 55% 이상의 리드타임 감소효과가 예상되었다. 또한 향후 제품 생산비율의 변화에 따른 민감도분석을 수행하였다. Mixed model production system means that various products are manufactured alternately in a line, and it has become a popular system in the era of multi-product small-quantity production. However, in the mixed model production system using flow line, the unbalance among stations is not inevitable because the workloads of stations cannot be the same. Thus, flow line system has been replaced to cellular manufacturing system for reducing the loss of waiting due to the unbalance of stations. In this paper, we introduce the simulation case study of an automated welding line which produces the parts of excavator. The factory has considered replacing the mixed model flow line to the cellular manufacturing system based on FMC concept. The increase of production quantity is estimated about 26.7%, and the lead time is reduced more than 55%. Furthermore sensitivity analyses are conducted considering the changes of product-mix.

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.

${\apha}$-Casein의 인산화 위치 규명을 위한 티타늄 다이옥사이드($TiO_2$) 방법의 최적화

김혜정,박자혜,백문창,Kim, Hye-Jeong,Park, Ja-Hye,Baek, Moon-Chang 대한약학회 2008 약학회지 Vol.52 No.5

Phosphorylation plays the most important role in cell signaling mechanism. Various methods to identify the phosphorylation sites of proteins using tandem mass spectrometry (MS/MS) have been reported recently. Furthermore, the enrichment strategy such as Titanium dioxide ($TiO_2$) method should be combined with MS/MS analysis to effectively identify phosphorylation sites. It is necessary to optimize phosphopeptide-enrichment strategy, $TiO_2$ method in this study, due to the low amount of phosphorylated form followed by analyzing them by MS/MS. To evaluate the several conditions to enrich phosphopeptides using $TiO_2$ method, we used ${\apha}$-casein as a standard phosphoprotein and analyzed a representative phosphopeptide (VPQLEIVPNpSAEER) peak of MS spectrum. Batch is better than column method for binding and 300 g/l DHB in loading buffer is better than lower concentration of DHB. 3% TFA and pH 10.5 shows high efficiency of phosphopeptide-enrichment for washing and elution steps, respectively. Finally we identified various efficient conditions of phosphopeptide-enrichment method using $TiO_2$. This optimized method would assist in reliable identifying thousands of phosphorylation sites existed in low abundance from various complex proteins.