송백류의 (松柏類) 분포를 중심으로 하는 한라산의 수직분포대

엄규백 (Kyu Baek Uhm) 한국식물학회 1962 Journal of Plant Biology Vol.5 No.2

UHM. Kyu Back (Dept. of Botany, Coll. of L. & S., Seoul National Univ.) Altitudinal zones of Mt. Hanla according to Coniferae distribution. Kor. Jour. Bot. V(2) : 17-20. 1962. Attitudinal zones of Mt. Hanla were geoecologically investigated, and compared with climatic index, according to Coniferae distribution. For climatic index, Warmth index was calculated on Mt. Hanla. With the reaultsobtained, the altitudinal zones can be classified into the following three zones: Coniferous forest zone; below 43˚(month-degrees) (above 1,450 m) Deciouous broad-leaf forest zone: 84˚-43˚ (600-1,450 m) Lucidophyllous forest zone: above 84 ˚ (below 600 m)

기후적 질서로 본 오대산 선식물상

정영호(Young Ho Chung),엄규백(Kyu Back Uhm) 한국식물학회 1961 Journal of Plant Biology Vol.4 No.2

CHUNG, Yung HO, and Kyu Baek UHM. (Dept. of Botany, Seoul National University.) Moss flora on Mt. Odae in its climatic aspects. Kor. Jour Bot 4(2) 33~40 1961 The moss flora and it`s geoecological study were made on Mt. Odae which is situated in the eastern part(37˚43` N. Lat., 120˚30` E. Long) of Korea. The total number of mosses collected on Mt. Odae in the autumn of 1960 is 50 species, 1 varieties and 1 subspecies, belonging to 23 families. For climate index, Warmth index and Humidity index were calculated on Mt. Odae. From the result, it was known that the c1imate of Mt. Odae is Humid temperate climte and that it`s vegetation zone is Deciduous broad-leaf forest zone. Moss Quotient of this mountain is 1.21 and it indicates that the plant climate of Mt. Odae is Hemicryptophytic climate. The moss flora of this mountain was discussed from the pnytogeographical point of view. The flora consists of the following elements: Holaectic element: 20 species (38.5%) North Pacific element: 1 (1.9%) Cosmopolitan element: 6 (11.6%) Tropical element: 1 (1.9%) East Asiatic element: 12 (23.05%) Korean-Japan element: 12 (23.05%) Coefficient of closeness was also calculated between the moss flora of Mt Odae and that of Mt. Sulak and Mt. Kwanak. It was known, therefore, that the flora relation between Mt. Odae and the Mt. Sulak was closer than that between Mt. Odae and Mt. Kwanak.

Investigating the Empirical Aspects of Communication Strategies

Uhm, Chul Joo 대한언어학회 2000 언어학 Vol.8 No.1

Uhm, Chul Joo. 2000. Investigating the Empirical Aspects of Communication Strategies. Linguistics 8-1, 353-377. This critical review on communication strategies (CS) characterizing the second language learners' communication problems will be concerned with some important empirical research that we should find useful when investigating the mechanism for processing that will explain how learners produce the utterances, and why they choose the solutions they do. Included are the summary of various typologies on which these empirical studies are based and the categorized review of the studies from reduction CS, compensatory CS and process approach perspectives. (Chonnam National University)

Problems of Assessing L2 Communicative Performance

Uhm, Chul Joo 대한언어학회 1996 언어학 Vol.4 No.-

Uhm, Chul Joo. 1996. Problems of Assessing L2 Communicative Performance. Linguistics 4, 95-108. Evaluation is an especially problematic aspect of proficiency-oriented language pedagogy. Here, therefore, I briefly review a few important problems at thee levels that seem to cause difficulties in the design, development and use of communicative tests such as: i) lack of theory of communication and of a description of language in use, ii) the loose definition of 'communicative proficiency" and the unclear idea of what to test, and iii) the search of a new way for achieving reliability. In this review we find out that the shift of focus in language teaching from language form to use is an exciting and promising development; however, we need to make endless efforts to develop the possibility of alternative assessment as valid and reliable procedures for this change. (Kwangju University)

Communication Strategies in Interaction between Korean EFL Learners

Uhm, Chul Joo 대한언어학회 1998 언어학 Vol.6 No.1

Uhm, Chul loo. 1998. Communication Strategies in Interaction between Korean BFL Learners. Linguistics, 6-1, 487-502. This case study examines the characteristics of communication strategies(CS) in non-native/non-native interaction. The Korean EFL learners' use of CS in interaction does not differ from that of native/non-native interaction observed previously in terms of holistic strategies and analytic strategies. On the other hand, the absence of linguistic strategies such as literal translation and foreignizing may underscore a distinction between NNS/NNS and NS/NNS interactions. In addition, since the difference between High and Low fluency groups in terms of the number and the kind of CS is observed, the transitional directionalities in interlanguage can be also proved. (Kwangju University)

Further Results on Piecewise Constant Hazard Functions in Aalen's Additive Risk Model

Uhm, Dai-Ho,Jun, Sung-Hae The Korean Statistical Society 2012 응용통계연구 Vol.25 No.3

The modifications suggested in Uhm et al. (2011) are studied using a partly parametric version of Aalen's additive risk model. A follow-up time period is partitioned into intervals, and hazard functions are estimated as a piecewise constant in each interval. A maximum likelihood estimator by iteratively reweighted least squares and variance estimates are suggested based on the model as well as evaluated by simulations using mean square error and a coverage probability, respectively. In conclusion the modifications are needed when there are a small number of uncensored deaths in an interval to estimate the piecewise constant hazard function.

염해지 우탁토양 (于拓土壤)에서 수도생육 및 수량에 미치는 토양개량제의 효과

엄대익(Dae Ick Uhm),유숙종(Sook Jong Yoo),엄택용(Taik Yong Uhm) 전북대학교 농업과학기술연구소 1989 농업생명과학연구 Vol.20 No.-

대수 주기 칸토어 다이폴 안테나의 복사 특성

엄선용(Sun-Yong Uhm),최학근(Sun-Yong Uhm) 한국전자파학회 2008 한국전자파학회논문지 Vol.19 No.3

본 논문에서는 기존 다이폴 소자 대신에 칸토어(Cantor) 다이폴 소자로 구성된 새로운 타입의 대수 주기 칸토어 다이폴 안테나(LPCDA: Log-Periodic Cantor Dipole Antenna)를 제안하였다. 제안된 안테나는 칸토어 다이폴소자를 사용함으로써 안테나의 소형화를 실현하였다. 제안된 안테나 타당성을 확인하기 위하여 1~4 ㎓의 주파수에서 동작하는 LPCDA를 설계하여 기존의 LPDA(Log-Periodic Dipole Antenna) 특성과 비교하였다. 그 결과, LPCDA는 LPDA보다 소자의 길이가 13.3 % 짧으면서도 상한 주파수 부근에서 이득은 약 2 ㏈ 증가하고, VSWR은 2 이하로 나타났다. In this paper, a novel log-periodic cantor dipole antenna(LPCDA), which is composed of the cantor-dipole elements instead of the existing dipole elements, is proposed. The proposed antenna makes possible the antenna miniaturization by using the cantor-dipole elements. To investigate the reliability of the proposed antenna, LPCDA is designed and analyzed at 1~4 ㎓ band and compared with LPDA(Log-Periodic Dipole Antenna) characteristics. It is shown that although the elements of LPCDA are 13.3 % shorter than LPDA, the gain increases about 2 ㏈ and VSWR is less than 2 in at the upper band.

A study on the Engineering verification of RF Passive Equipment for Communication, Ocean and Meteorological Satellite (COMS)

Uhm, Man-seok,Lee, Ju-Seop,Yun, So-Hyeun,Noh, Youn-Sub,Park, Jong-Heung 통신위성우주산업연구회 2004 Joint Conference on Satellite Communications Vol.2004 No.-

본 논문에서는 2008 년에 발사될 통신해양기상위성용 RF 수동부품의 기술 검증을 보였다. 이들은 입력 광대역 필터, 협대역 채널 필터, 메니폴드 형태 멀티플렉서, 다이플렉서 등의 수동 부품들이다. 기술검증의 목적은 선정된 부품들이 그 동안 ETRI 에서 축적된 국내 기술로 개발이 가능한지 확인한 후 통신 위성에 사용하고자 하는 것이다. 입력 필터 어셈블리는 중계기의 입력 신호를 검사하기 위한 교차 방향성 시험 결합기와 상향 링크 대역 신호를 통과 시키는 입력 필터로 이루어져있다. IF 채널 필터로는 무게와 부피를 줄이기 위해서 4차 체비체프 combline 구조가 이용되었다. RF 채널 필터는 무게와 부피를 줄이기 위해서 8 차 타원형 필터와 2차 군지연 등화기를 이중모드 형태로 설계하였고, 출력 멀티플렉서는 저 손실 특성을 갖고, 무게 및 부피가 적은 메니폴드 형태가 이용되었다. 다이플렉서는 E 평면 T접합부에 아이리스를 두어 정합이 용이하도록 하였고, 송신부 필터는 용량성 아이리스를 수신부는 유도성 아이리스를 이용한 필터가 적용되었다. 모든 부품들의 성능 결과는 해석 결과와 일치하였고, 요구 규격을 만족하였다. 이번 기술 검증을 바탕으로 비행모델급 부품들이 개발되어 통신해양기상 위성에 사용될 예정이다. This paper presents the engineering verification of RF passive equipment for Communication, Ocean and Meteorological Satellite (COMS) to be launched in 2008. Those are the passive equipment for the input wide band filter, RF/IF channel filters, a manifold multiplexer, and a diplexer. The objective of this engineering verification is to study the feasibility of those equipment to be applied to communication satellite. The input filter assembly (IFA) consists of a cross directional test coupler to check the input signal level of the transponder and an input band pass filter to pass the uplink band signals. Four-pole Chebyshev combline structure is chosen for the IF channel filter to reduce the mass and volume. RF channel filter and output multiplexer (OMUX) is used for the channelization of the frequency band into a number of RF channels. Dual mode technique is adopted in both 8-pole elliptic channel filters and 2-pole external equalizers for mass and volume reduction for RF channel filters. For low insertion loss, mass, and volume reduction, manifold type is employed for output multiplexer. E-plane waveguide T-junction of the diplexer with the inductive iris is used for a matching elements to reduce the computation time for optimized performance. The inductive and capacitive irises are used for receiving and transmitting filter, respectively. The test results of all equipment show good agreement with the simulation results and are compliant th the requirement of each equipment. Followed by this verification, the flight model equipment will be developed for the COMS.

Influence of reactive oxygen species on the sterilization of microbes

Uhm, H.S.,Choi, E.H.,Cho, G.S.,Hwang, D.H. Elsevier 2013 Current Applied Physics Vol.13 No.suppl1

The influence of reactive oxygen species on living cells, including various microbes, is discussed. A sterilization experiment with bacterial endospores reveals that an argon-oxygen plasma jet very effectively kills endospores of Bacillus atrophaeus (ATCC 9372), thereby indicating that oxygen radicals are the key element of sterilization. Ozone in acidic water also kills endospores of B. atrophaeus very effectively, demonstrating the capability of cleaning a large surface area contaminated by toxic biological agents. The viable microbe numbers after the contact with acidic ozone water directly correlate with increase in the ozone decay time in water after lowering the pH value of water from pH = 7 to 4 indicating that acidic ozone water is an effective means of sterilizing microbes. However, advanced cells such as fertilized eggs were not greatly influenced by the acidic ozone water. Also, both human and canine cells after treatment with the acidic ozone water prospered without showing signs of stress due to ozone in acidic water. This study suggests that antioxidant enzymes such as superoxide dismutase can be developed in the advanced cells to protect themselves from attacks by reactive oxygen species. Meanwhile, the advanced cells utilize oxygen by certain enzymes, proliferating life on earth.