절삭 깊이의 무작위 제어를 적용한 다이아몬드 선삭공정에서 소재회전 반경에 따른 미세패턴의 크기변화 분석 연구

정지영,한준세,최두선,제태진,Jeong, Ji-Young,Han, Jun-Se,Choi, Doo-Sun,Je, Tae-Jin 한국금형공학회 2020 한국금형공학회지 Vol.14 No.1

Ultra-high brightness and thin displays need to optical micro-patterns which can uniformly diffuse the lights and low loss. The micro random patterns have characteristics to rise the optical efficiency such as light extraction, uniform diffusion. For this reason, various fabrication processes are studied for random patterns. In this study, the micro random patterns were machined by diamond turning which used a controlled cutting tool path with random cutting depth. The machined patterns had random shape and directionality along the circumferential direction. The average width and length of machined random pattern according to rotation radius were 40.13㎛~55.51㎛ and 37.25㎛~59.49㎛, and these results were compared with the designed result. Also, the machining error according to rotation radius in diamond turning using randomly controlled cutting depth was discussed.

산지별 마늘의 향기 항산화활성과 열처리 효과

정지영(Ji Young Jeong),우관식(Koan Sik Woo),황인국(In Guk Hwang),윤향식(Hyang?Sik Yoon),이연리(Youn Ri Lee),정헌상(Heon?Sang Jeong) 한국식품영양과학회 2007 한국식품영양과학회지 Vol.36 No.12

생마늘과 열처리에 따른 마늘의 향기 특성과 향기추출물의 항산화활성을 확인하고자 국내산 한지형 마늘 3종(단양, 서산, 의성마늘)과 난지형 마늘 3종(남해, 남도, 대서마늘), 중국산 마늘에 대하여 simultaneous distillation and extraction(SDE) 방법으로 향기 성분을 추출하여 GC/MS로 동정하고 항산화활성을 측정하였다. 생마늘의 주요 향기성분은 allyl methyl sulfide, methyl-2-propenyl disulfide, diallyl disulfide, 2-ethylidene-1,3-dithiane, methyl-2-propenyl trisulfide, di-2-propenyl trisulfide 및 2-vinyl-4H-1,3-dithiin 등으로 나타났다. 항산화활성이 우수한 것으로 알려진 diallyl disulfide, methyl-2-propenyl trisulfide 및 di-2-propenyl trisulfide 등은 중국산 마늘보다 한지형 마늘이 많이 함유하고 있었다. 향기성분은 열처리시 2-propanone, allyl mercaptan, methyl formic acid, 2-methyl butanal 2-methyl thiophene, methyl pyrazine, 2,2-dimethyl-1,3-dithiane 및 2-propenyl propyl disulfide 등이 새롭게 생성되었으며, allyl methyl sulfide, allyl alcohol 및 allyl sulfide 등의 분자량이 작은 화합물의 함량이 증가하였다. 산지별 생마늘의 향기 추출물에 대한 항산화활성은 농도 의존적으로 증가하였으며, 단양, 남해 및 중국산은 각각 20.07, 34.62 및 9.71%의 항산화활성을 나타내었고, 열처리 후에는 각각 79.90, 93.59 및 77.26%로 증가하였다. The objectives of this study were to compare the aroma characteristics and antioxidant activity of raw and heated garlic (130℃, 2 hr) from different cultivation areas (Danyang, Seosan, Uiseong Namhae, Namdo, Daeseo and China). The volatile compounds were extracted by simultaneous steam distillation extraction and identified with gas chromatography/mass spectrometer. The major volatile compounds of raw garlic were sulfur compounds such as diallyl disulfide, methyl-2-propenyl trisulfide, di-2-propenyl trisulfide etc. After heating, the major volatile compounds were allyl mercaptan, methyl pyrazine, 2,2-dimethyl-1,3-dithiane, 2-propenyl propyl disulfide, allyl methyl sulfide, allyl alcohol, and allyl sulfide etc. The DPPH radical scavenging activity (EDA, %) of volatile compounds from raw garlic and heated garlic was increased in a dose-dependent manner. The antioxidant activities (EDA, %) of volatile compounds from raw garlic cultivated in Danyang, Namhae and China were 20.07, 34.62, and 9.71% respectively. After heating, these values were increased to 79.90, 93.59, and 77.26% respectively. Results showed that heat treatment significantly enhanced the antioxidant activities (EDA, %) of the garlic.

일축인장시험을 통한 투명교정장치용 고분자 소재의 역학적 특성 분석

정지영(Ji-Young Jeong),제태진(Tae-Jin Je),전은채(Eun-chae Jeon) 한국기계가공학회 2018 한국기계가공학회지 Vol.17 No.5

Clear aligners are popular in the field of dental orthodontic treatment because they offer a discreet alternative to braces due to their use of transparent materials. They are formed from flat transparent polymer materials by hot pressed molding. It is necessary to know the mechanical properties of the polymer materials to be able to form the exact shapes of the clear aligners. However, this information is not publicly available. In this study, we present a method to reliably measure the mechanical properties of clear aligner polymer materials and analyze the factors effecting these mechanical properties. First, we surveyed standards related to the mechanical properties of polymer materials to obtain reliable data. Consequently, ISO 527 was selected for use in this study because of the size and thickness of the flat transparent polymer material. The uniaxial tensile tester was constructed and it was verified whether displacement of a crosshead could be regarded as a displacement of gauge-length by optical analysis. Uniaxial tensile tests of three thicknesses from three different companies were performed and each engineering stress-strain curve was measured. Tensile strengths and elastic moduli were obtained by analysis of the stress-strain curves. The tensile strength and elastic modulus of ISO 527 was found to be approximately 50MPa and 2.3GPa, respectively. Both values showed material and thickness dependency.

펩티도글리칸에 의한 단핵세포의 Tumor necrosis factor-α 발현 기전 연구

정지영(Ji-Young Jeong),손용해(Yonghae Son),김보영(Bo-Young Kim),김관회(Koanhoi Kim) 한국생명과학회 2019 생명과학회지 Vol.29 No.11

본 연구에서는 펩티도글리칸이 단핵세포의 TNF-α 발현에 미치는 영향을 조사하였고, 또한 펩티도글리칸에 의한 TNF-α 발현에 관련된 세포의 요소들을 연구하였다. 사람의 단핵세포주인 THP-1 세포를 펩티도글리칸에 노출시키는 경우 TNF-α 분비 증가뿐만 아니라 TNF-α 유전자 전사를 유도하는 결과를 가져왔다. TLR-2/4의 억제제인 OxPAPC은 펩티도글리칸에 의한 TNF-α의 발현을 저해하였다. 그리고 U0126, SB202190, SP6001250, LY294002, Akti IV, rapamycin, NAC, DPI 같은 약리학적 저해제 또한 TNF-α 발현을 유전자/단백질 수준에서 상당히 약화시켰다. 그러나 polymyxin B는 TNF-α 발현에 영향을 주지않았다. 따라서 펩티도글리칸이 TLR-2, PI3K, Akt, mTOR, MAPKs, ROS 등을 통하여 단핵세포의 TNF-α 발현을 증가시킴을 확인하였다. Peptidoglycan (PG) is found in atheromatous lesions of arteries, where monocytes/macrophages express inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α). This study investigated the effects of PG on TNF-α expression and examined possible cellular factors involved in TNF-α upregulation. The overall aim was to identify the molecular mechanisms underlying inflammatory responses to bacterial pathogen-associated molecular patterns in the artery. Exposure of human THP-1 monocytic cells to PG enhanced the secretion of TNF-α and induced its gene transcription. Inhibition of TLR-2/4 with OxPAPC significantly inhibited TNF-α gene expression, whereas inhibition of LPS by polymyxin B did not. The PG-induced expression of TNF-α was also significantly suppressed by pharmacological inhibitors that modulate activities of cellular signaling molecules; for example, U0126 (an ERK inhibitor), SB202190 (a p38 MAPK inhibitor), and SP6001250 (a JNK inhibitor) significantly attenuated PG-induced transcription of TNF-α and secretion of its gene product. TNF-α expression was also inhibited by rapamycin (an mTOR inhibitor), LY294002 (a PI3K inhibitor), and Akt inhibitor IV (an Akt inhibitor). ROS-regulating compounds, like NAC and DPI, also significantly attenuated TNFα expression induced by PG. These results suggest that PG induces TNF-α expression in monocytes/ macrophages by multiple molecules, including TLR-2, PI3K, Akt, mTOR, MAPKs, and ROS.

열전소자 적용을 위한 LED 엔진 모듈 설계와 특성 분석

정지영(Ji-Young Jeong),강민규(Min-Gyu Kang),김승재(Seung-Jae Kim),유영문(Young Moon Yu) 한국조명·전기설비학회 2016 조명·전기설비학회논문지 Vol.30 No.7

Variation of thermal resistivity depending on temperature difference and measurement of thermal resistivity of thermoelectric device in LED lighting engine module were studied. Power generated from waste heat and photometric characteristics of LED engine module were measured. From the measured and analysed data, the followings were concluded. Control of temperature difference at the low temperature was advantageous for LED module compared to temperature difference control at high temperature. The sum of the measured thermal resistance of LED module and thermoelectric device was 2.654K/W and the measured total thermal resistance was 2.41K/W. In a thermal simulation, minimum LED p-n junction temperature was 69.3℃ when 23 pieces of pins with 1mm thickness were used. When 700mA was applied to the LED engine module, 0.086W of maximum power was obtained with 0.15A of load. Light efficiency of LED module with thermoelectric device was 126.9lm/W and 3.7lm/W of efficiency decrement.

LED터널등 모듈의 폐열활용을 위한 열전소자의 발전 성능 분석

정지영(Ji-Young Jeong),허인성(In-Sung Her),이세일(Se-Il Lee),김명호(Myeong-Ho Kim),유영문(Young Moon Yu) 한국조명·전기설비학회 2015 조명·전기설비학회논문지 Vol.29 No.8

In this paper, we propose the LED(Light-Emitting-Diode) emergency lighting in a tunnel by using the thermoelectric devices. To achieve high generated power, thermoelectric device should be have high Seebeck coefficient and small contact area. Also, we reveal that a moderate heatsink required for high generated power. From the waste heat of LED tunnel lighting module (25W), the generated power was 0.062W by thermoelectric device, and it could illuminate for 1hour after charge the battery of emergency lighting during about 101hours.

바이모프 압전소자를 이용한 자세교정 신발에 관한 연구

정지영(Ji-young Jeong),박지훈(Ji-hoon Park),김남윤(Nam-Yoon Kim) 한국통신학회 2015 한국통신학회 학술대회논문집 Vol.2015 No.11

근대 용두산공원의 성립과 그 변용에 관한 연구

정지영 ( Ji Young Jeong ),조승래 ( Seung Rae Cho ),강영조 ( Young Jo Kang ) 한국전통조경학회(구 한국정원학회) 2006 한국전통조경학회지 Vol.24 No.1

중장년 성인의 평생학습을 통한 ‘더불어 나이듦’에 관한 현상학적 연구

정지영(Ji-Young Jeong) 한국성인교육학회 2023 Andragogy Today : International Journal of Adult & Vol.26 No.1

본 연구의 목적은 중장년 성인의 평생학습 활동을 통한 더불어 나이듦의 의미를 탐색하는 데 있었다. 본 연구는 노화의 결정요소 고찰에 중점을 둔 기존 노화 관련 연구들과 세 가지 측면에서 차별화된 접근법을 사용하였다. 첫째, 연구 대상을 중장년으로 확대하고 노화를 ‘더불어 나이듦’이란 한글 개념으로 바꾸어 사용하였다. 단순히 생물학적 늙음이 아닌, ‘되어감’에 초점을 둔 개념에 초점을 두었다. 둘째, 중장년기의 중요한 특징이 타자와의 관계성에 있다는 인식하에 ‘더불어 나이듦’으로 정의하였다. 셋째, 더불어 나이듦의 경험에서의 평생학습의 역할을 탐색하였다. 연구 목적을 위해 평생학습을 지속적으로 하고 있는 중장년 16명을 선정하여 다단계 심층 면담을 진행하였으며 현상학적 연구 방법을 사용하였다. 연구 결과로 중장년 성인의 평생학습을 통한 더불어 나이듦의 의미는 ‘나이듦의 인식과 불안’, ‘자아 정체성에 대한 의문’, ‘나를 찾기 위한 더불어 학습’, ‘평생학습을 통한 더불어 살기’로 나타났다. This study aims to explore the meaning of ‘aging together’ through lifelong learning activities of middle-aged and elderly adults. This study used a differentiated approach in three aspects from the existing aging-related studies that focused on examining the determinants of aging. First, the study subjects were expanded to middle-aged and elderly aged, and ‘aging together’ was changed to the Korean concept of ‘aging’, which focuses on ‘becoming’ not simply getting older biologically. Second, it was defined as 'aging together' with the recognition that an important characteristic of middle-aged and elderly adult is the relationship with others. Third, the role of lifelong learning in the experience of aging was also explored. For the purpose of the study, 16 middle-aged and elderly adults, who were doing lifelong learning activities were selected and multi-level in-depth interviews were conducted, and a phenomenological research method was used. As a result of the study, the meaning of aging together through lifelong learning of middle-aged and elderly adults was found to be ‘awareness and anxiety of aging', 'question about self-identity', 'learning together to find myself', and 'living together through lifelong learning'.

SPM-based Data Storage System의 Feedforward Decoupling 기법을 적용한 제어기 설계

정지영 ( Ji Young Jeong ),문준 ( Jun Moon ),이충우 ( Choong Woo Lee ),정정주 ( Chung Choo Chung ),김영식 ( Young Sik Kim ) 정보저장시스템학회 2007 정보저장시스템학회논문집 Vol.3 No.2