Light-extraction efficiency control in AlGaN-based deep-ultraviolet flip-chip light-emitting diodes: a comparison to InGaN-based visible flip-chip light-emitting diodes.

Lee, Keon Hwa,Park, Hyun Jung,Kim, Seung Hwan,Asadirad, Mojtaba,Moon, Yong-Tae,Kwak, Joon Seop,Ryou, Jae-Hyun Optical Society of America 2015 Optics express Vol.23 No.16

<P>We study light-extraction efficiency (LEE) of AlGaN-based deep-ultraviolet light-emitting diodes (DUV-LEDs) using flip-chip (FC) devices with varied thickness in remaining sapphire substrate by experimental output power measurement and computational methods using 3-dimensional finite-difference time-domain (3D-FDTD) and Monte Carlo ray-tracing simulations. Light-output power of DUV-FCLEDs compared at a current of 20 mA increases with thicker sapphire, showing higher LEE for an LED with 250-관m-thick sapphire by ~39% than that with 100-관m-thick sapphire. In contrast, LEEs of visible FCLEDs show only marginal improvement with increasing sapphire thickness, that is, ~6% improvement for an LED with 250-관m-thick sapphire. 3D-FDTD simulation reveals a mechanism of enhanced light extraction with various sidewall roughness and thickness in sapphire substrates. Ray tracing simulation examines the light propagation behavior of DUV-FCLED structures. The enhanced output power and higher LEE strongly depends on the sidewall roughness of the sapphire substrate rather than thickness itself. The thickness starts playing a role only when the sapphire sidewalls become rough. The roughened surface of sapphire sidewall during chip-separation process is critical for TM-polarized photons from AlGaN quantum wells to escape in lateral directions before they are absorbed by p-GaN and Au-metal. Furthermore, the ray tracing results show a reasonably good agreement with the experimental result of the LEE.</P>

업종에 따른 연 취급 사업장의 기중 연 농도 및 연 노출 수준 평가

이병국,김용배,리갑수,안현철,김화성,이용진,황규윤,장봉기,이성수,안규동 순천향대학교 산업의학연구소 1999 순천향산업의학 Vol.5 No.1

In order to obtain an useful information for health management and biological monitoring of lead exposed workers, Authors tried to investigate air lead level and the lead exposed level of workers in lead industry according to occupational category. The subjects in our study were 2074 workers in 7 lead-using industries, and study subjects were divided into 4 occupational categories such as storage battery industry (type 1), primary smelting industry (type 2), secondary smelting industry (type 3) and litharge making industry (type 4). Blood zincprotoporphyrin concentration (ZPP), blood lead concentration (PbB) and urinary δ -aminolevulinic acid (ALAU), hemoglobin (Hb), hematocrit (Hct) were selected as the indices of lead exposure. Personal variables such as age, work duration were also collected. The results were as follows. 1. The geometric mean air lead in 9 lead-using industry was 0.1133±4.3120 ㎎/㎥, and that in type 1, 2, 3 and 4 was 0.1038±3.4952 ㎎/㎥, 0.0429±3.4329 ㎎/㎥, 0.1877±2.5123 ㎎/㎥ and 0.9961±5.2910 ㎎/㎥, respectively. 2. The mean ZPP in 9 lead-using industry was 53.1±28.0 ㎍/㎗, and that in type 1, 2, 3 and 4 was 52.0±24.8 ㎍/㎗, 48.0±16.4 ㎍/㎗, 109.8±85.6 ㎍/㎗ and 74.3±37.8 ㎍/㎗, respectively. There was significant difference in ZPP according to occupational category (P<0.01). The percents of lead workers whose ZPP were above 100 ㎍/㎗ in type 1, 2, 3 and 4 were 4.0%, 1.7%, 34.3% and 21.6%, respectively. 3. The mean PbB in lead-using industry was 26.0±11.2 ㎍/㎗, and that in type 1, 2, 3 and 4 was 25.3±11.1 ㎍/㎗, 26.7±8.8 ㎍/㎗, 50.3±15.2 ㎍/㎗ and 36.4±11.0 ㎍/㎗, respectively. There was significant difference in PbB according to occupational category (P<0.01). The percents of lead workers whose PbB were above 40 ㎍/㎗ in type 1, 2, 3 and 4 were 10.4%, 7.7% 71.9% and 43.2%, respectively. 4. While the correlation of Hb corrected PbB with ZPP was higher than non corrected PbB, the correlation of log-transformed ZPP with PbB was higher than non corrected ZPP. 5. Simple linear regressions of PbB and corrected PbB as independent variable with ZPP, log-transformed ZPP and ALAU as dependent variable were statistically significant (P0.01). Coefficient of determination of corrected PbB with other variables was higher than non corrected PbB. As the result of this study, it was suggested that reconsideration of environmental and biological monitoring program was highly recommended for secondary smelting and litharge making industry.

최신토지피복자료를 이용한 대구시의 열환경 수치모의

이현주(Hyun-Ju Lee),이귀옥(Kwi Ok Lee1),원경미(Gyeong Mee Won),이화운(Hwa Woon Lee) 한국대기환경학회 2009 한국대기환경학회지 Vol.25 No.3

Plant regeneration from callus of Iris odaesanensis Y. N. Lee native to Korea via organogenesis

Bae, Kee-Hwa,Yoo, Kyoung-Hwa,Lee, Mi-Hyun,Jeong, Jae-Hun,Choi, Yong-Eui,Yoon, Eui-Soo The Korean Society of Plant Biotechnology 2013 식물생명공학회지 Vol.40 No.3

Iris odaesanensis Y. N. Lee. is an important endangered and native plant belonging to the family Iridaceae in Korea. This study describes a method for rapid micropropagation of this species via from leaf, rhizome and root explants derived calli. Leaf, rhizome and root explants were cultured on Murashige and Skoog (MS) medium supplemented with 2,4-dichlorophenoxy acetic acid (2,4-D) for callus induction. Rhizome explants yielded calli at a frequency of 72% when cultured at 1.0 mg/l 2,4-D. Calli were maintained at 1.0 mg/l 2,4-D. These calli were transferred to MS medium supplemented with 0, 0.5, 1.0, and 2.0 mg/l 2,4-D in combination with 0, 0.5, 1.0, and 3.0 mg/l BA for adventitious shoot induction. The highest number of adventitious shoot (228.9 per petri-dish) were formed at 1.0 mg/l 2,4-D and 1.0 mg/l BA. WPM medium was the best to convert calli into plantlets, where up to 98.2% of calli were regenerated into plantlets. This in vitro propagation protocol should be useful for conservation of this endangered plant.

간호실무에서 신봉이론(Espoused theories)에 대한 탐색적 연구

서문자,김혜숙,이은희,박영숙,조경숙,강현숙,임난영,김주현,이소우,조복희,이명하,지성애,하양숙,손영희,권성복,김희진,추진아 성인간호학회 2001 성인간호학회지 Vol.13 No.1

As a nursing practice involves nurses' actions in a specific context of health care, this study has focused on exploring the espoused theories in nursing practice within the action science perspectives, Espoused theories are the belief, principles, and rationale expressed by the practitioner as guiding her/his actions in a situation of practice. The data were analysed qualitatively and 25 elements of espoused theories of nursing action were identified and clustered into 6 categories. The 25 elements of espoused theories are as follows: The clinical nurse worked in wholistic and individual nursing, focussed on the patient's needed, comfort and supportive nursing (5 theories of nursing goal) ; excellent skills, knowledge based, assessment and data collection, explaining, educating or a scientific basis(6 theories of nursing intervention): advocacy, value oriented, treatment, account- ability and commitment(4 theories of nursing ethics) ; human respect. partnership, trust(3 theories of patient-nurse relationship) : knowledgable, accumulated clinical experiences and personally lived experiences. positive perspectives(4 theories of nurse), role of intervention. rewarding peer relationship(3 theories of situations) The above mentioned espoused theories are similar to that of nursing textbooks which students learned through basic nursing education and almost the same as the Acts ofa Nurse in Korean. However, we are doubtful whether nurses actually do as they think. Therefore. it is recommended to review the theories-in-use in order to and any discrepancies between the espoused theories and the reality of nursing actions

일부 사업장 건강증진사업 실태조사 및 요인분석

이경화,이원철,이강숙,홍현숙,송연이 가톨릭대학교 산업의학센터 2000 韓國의 産業醫學 Vol.39 No.2

For the purpose of access the health promotion activities in 138 worksite which had more than 50 workers, we surveyed the questionnaire on May and September 1998. The results of survey were as follows: 1.59 companies(45.1%) were conducting the health promotion activities. Most of them were manufacturing and located Kyung-sang province and had nurses as a health manager. 2.Companies operating the health promotion activities had significant higher degree of satisfaction and usage of welfare facilities than non-operating companies. 3.The level of knowledge for regulations, professional skills, and performance related health promotion was low in all companies. Top manager's interest and will for investment to health promotion was significant lower in non-operating companies. 4.The reasons why the health promotion program was not operated, were low budget, top manager's indifference, lack of information, work overloading, no human resource, an insufficient governmental support in order. 5.The most necessary items for program were education and promotion, budget, and governmental support. Needed personnel were nurses, fitness trainner, and necessary program were health management, exercise, nutrition, and stress counselling. For comparing before and after IMF, amount of budget was decreased. In conclusion, this study suggested that major barriers to conduct health promotion activities were lack of budget, lower interest of top managers, and insufficient professional information, therefore detail health promotion program would be developed and supported by government.

總括生産計劃에서 適定 퍼지수 比較法의 選擇에 관한 硏究

李相玩,朴永和,南賢祐,尹延根 동아대학교 공과대학 부설 한국자원개발연구소 1992 硏究報告 Vol.16 No.1

When using any of the aggregate production planning techniques mentioned in previous studies, it is generally assumed that the inputs of information are deterministic and easy to generate. However, the problem is more complex if the criteria and informations are expressed imprecisions. Therefore, it requires suitable method to deal with imprecisions. For select proper comparison method of fuzzy numbers in aggregate production planning with imprecise informations or criteria, this study use Dubois & Prade fuzzy number comparison method and Li-Lee fuzzy number comparison method among comparison methods fuzzy numbers. And then, proper method between two methods is selected. Also it is presented illustration.

뇌척수액내의 결핵균 α- 및 β- 단백항원에 반응하는 항결핵균항체의 정량적 측정에 의한 결핵성 수막염의 진단적 접근

이경숙,백태현,김화중,박정규,최대경 충남대학교부설 생명공학연구소 1992 생물공학연구지 Vol.2 No.-

The aim of this study was to develop an immunologic method for the diagnosis of tuberculous meningitis with a sensitivity greater than that of the initial bacterial smear while maintaining good specificity. Purified α-antigen and β-antigen from unheated culture filtrate of Mycobacterium tuberculosis H37Rv was applied for its potential diagnostic utility in detection of IgG, IgM and IgA antibody in the cerebrospinal fluids of 14 patients with tuberculous meningitis and 27 non-tuberculous patients by ELISA at the CSF dilution of 1 : 5. The results were summarized as follows: 1. The mean ELISA values of IgG antibody activity to purified α-antigen in CSF of 14 patients with tuberculous meningitis and 27 controls were 0.769±0.638 and 0.090±0.068, respectively. The specificity and sensitivity were 96.3% and 92.9%. The mean ELISA values of IgG antibody activity to purified β-antigen were 0.668±0.507 and 0.092±0.070, respectively. The specificity and sensitivity were 92.6% and 92.9%. 2. The mean ELISA values of IgM antibody activity to purified α-antigen in CSF of 14 patients with tuberculous meningitis and 27 controls were 0.629±0.585 and 0.007±0.076, respectively. The specificity and sensitivity were 92.6% and 92.9%. The mean ELISA values of IgM antibody activity to purified β-antigen were 0.637±0.550 and -0.028±0.082. The specificity and sensitivity were 96.3% and 85.7%. 3. The mean ELISA values of IgA antibody activity to purified α-antigen in CSF of 14 patients with tuberculous meningitis and 27 controls were 0.266±0.330 and -0.22±0.032. The specificity and sensitivity were 96.3% and 85.7%. The mean ELISA values of IgA antibody activity to purified β-antigen were 0.031±0.419 and -0.048±0.037. The specificity and sensitivity were 96.3% and 85.7%. These results suggest that the purified α-and β-antigen are useful for the diagnosis of tuberculous meningitis.

일회통과 관류실험시 물의 수송 : 관류액의 종류와 삼투압의 영향 Effects of Some Perfusates and Their Osmolality

이정화,이현주,용철순,오두만 영남대학교 약품개발연구소 1995 영남대학교 약품개발연구소 연구업적집 Vol.5 No.-

The single pass perfusion experiments were performed in anesthetized rata to investigate the effects of perfusates and their osmolality on the water transport and to determine the correlation between the extent of water transport and the volume change of perfusate. Phenol red was used as a nonabsorbable marker. In normal rats, when perfused at a flow rate of 0.5 ml/min 2-(N-morpholino) ethanesulfonic acid (MES) aid Sorensen's phosphate hullers showed minimal net water transport as 0.125 and 0.173 %/cm of intestinal length, respecetively. Hypotonic perfusate of 200 mOsm㎏ of water and hypertonic perfusate of 400 mOsm/㎏ of water generated significant water transport compared with isotonic perfusate of 300 mOsn/㎏ of water. There was a linear correlation between the attent of water transport and the volume change of perfusate, suggesting that the volume change can be used as a measure of water transport.

철근콘크리트 커플링 보의 해석기법과 병렬 전단벽의 거동 비교

이주화,박완신,윤현도 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2(구조계)

Ductile coupled flexural walls are the primary seismic load resisting systems of many structures. The coupling beams of these structures must exhibit excellent ductility and energy absorption ability. But the present analytical method about nonlinear behavior of reinforced concrete coupling beam scarcely anything. This paper composed of two subjects. First subject is a suggestion of analytical method of diagonally reinforced concrete coupling beam and longitudinally reinforced concrete coupling beam and rhombic coupling beam, and selected 5 specimens for that. Second subject is a comparison of seismic behavior of fully coupled shear wall and partially coupled shear wall. This paper used lDAHC-2D and Midas Gen 4.3.1 for the purpose of achievement these subjects. Suggested analytical method expected that it showed good agreement with reinforced concrete coupling beam inelastic behavior. Also, comparison of seismic behavior result showed that fully coupled shear wall have good behavior than partially coupled shear wall.