진균성 부비동염의 임상적 양상과 내시경수술의 치료 결과

이봉재,김혁,김재호,김용재 대한이비인후과학회 1998 대한이비인후과학회지 두경부외과학 Vol.41 No.3

다중슬랙모선 전력조류계산법과 행렬의 반복계산식을 이용한 효율적인 상정사고 해석

심건보,이봉용 弘益大學校 科學技術硏究所 1994 科學技術硏究論文集 Vol.5 No.-

Contingency analysis requires usually many simulations in order to identify weak points in the system. Often it is time conusming although its results may be exact. This paper suggests a quite simple and efficient method with the matrix iterative techniques. Bus power equations are changed so that state quantities such as voltage magnitudes and angles can be found easily after assumed contingencies. Efficiency comparison shows that the suggested method is quite superior, 7 and 192 times better efficiencies than DC load flow and AC load flow, respectively are expected in n=100 scale system. Particulary, usual one-slack load flow is avoided to get more realistic results. Multi-slack bus load flow is introduced.

버들여뀌의 水溶性 成分의 殺충效果

송봉준,유승곤,이보성 충남대학교 공업교육연구소 1986 論文集 Vol.8 No.3

The water-soluble extract of Persicaria hydropiper was investigated with respect to its insecticidal effect. Small plant parasitic insects such as Aphis and Perichaeta communissma were wholly killed within 60 min, in the aqueous solution including 1250 ppm of the water-soluble extract. This extract was passed through cation and anion resins, and the non-adsorption parts were fractionated with membrane filters. The lower molecular fraction (MW/<500) exhibited a strong insecticidal effect and a new component having R_f value of 0.24 has been observed on the TLC from this low molecular fraction.

구진상괴사성 결핵진 3례

손보성,송준영,정재봉,김병천,이상숙,류영욱,이규석 啓明大學校 醫科大學 1994 계명의대학술지 Vol.13 No.4

Papulonecrotic tuberculid is an eruption of necrotizing papules, particularly affecting the extremities and occurring in more or less symmetrical crops, and responding to antituberculosis therapy. Individual lesions heal with scarring. Histologically, vascular involvement is seen in early lesions. Late lesions are divided into two forms. In superficial forms, wedge shaped area of necrosis forms in epidermis and upper dermis. Epithelial and lymphoid cells gather around its periphery. In deep forms, with no epidermal change, granulomatous changes surrounded by well defined palisading histiocyte and lymphoid, epithelioid cells are seen. In mid-dermis and perivascular area, vessel shows vasculitis. In the first case, leukocytoclastic vasculitis and early granuloma formation were seen. In the second case, palisading granuloma formation was seen. In the third case, tuberculoid granuloma formation was seen. We report three cases of papulonecrotic tuberculid showing three different stages of histological finding, in individual cases.

공급지장비 평가에 의한 전원계획에서의 적정예비력 연구

李鳳容,沈建輔 弘益大學校 1990 弘大論叢 Vol.22 No.2

Traditionally the reliability index for generation planning has been used 0.7[days/year] in LOLP in this country. However, it seems to be time that the index should be reexamined as the scale of the power system has been grown remarkably during past decades. Reliability expression by LOLP may not be enough since it lacks information of such as severity of supply shortage. It can be complemented by other indexes, but these are not widely used due to their complication. This paper presents a result how supply shortage costs influence reserve levels of generation planning and that the appropriate level has been tried to be determined from those influences. New reliability index is suggested.

添加酸化物이 Ni-Zn Ferrite의 電氣 및 磁氣的 性質에 미치는 影響

朴奉斗,南寶植 慶北大學校 産業開發硏究所 1982 硏究報告 Vol.10 No.-

The variation of electromagnetic properties on Ni-Zn ferrite with additive oxides (As_2O_3, Bi_2O_3, and SnO) was measured with Hysteresis Loop Tracer at this sintering temperature range of 1150℃∼1350℃. The experimental results indicate that specific resistances were 0.3×10 exp (5)-2.8×10 exp (5)Ω ㎝, and the maximum initial permeability μ_i was 210 H/m, the maximum permeability μ_m 2450^* H/m, the maximum residual magnetization Br 900 gauss, and the minimum coercive force Hc 0.35 Oe. The loss coefficient shows that the additive oxides have Low value (1.3×10 exp (-4), at 2.5 MHZ) compared with the non-additives calcinated at 1250℃.

사료용 옥수수 연구 N. 조사료용 CNU 육성 교잡종 옥수수의 수량관련 주요특성

이희봉,정재영,김용일,박보영,지희정,문현귀 충남대학교 농업과학연구소 2006 농업과학연구 Vol.33 No.1

This study was carried out to compare a yield performance about CNU maize hybrids developed at the Maize Genetics and Breeding Lab, in Chungnam National University. Among the hybrids incorporated in the test, CNU 3 and 1 showed higher dry matter per 10a and lower kernel yield per 10a than check hybrid, Kwanganok. Hongchon 5 and Suwon169 showed higher kernel yield than Kwanganok. The average yield of CNU 3 hybrid in dry matter and CNU 4 in kernel yield were 2,106kg/10a and 854kg/10a in regional adaptability test, which were increased 33% and 8% compared with a check hybrid, respectively. Also, these hybrids had better stay green characteristics than check hybrid and showed moderately resistance to corn borer and leaf spot.

經濟給電방식에 의한 確率的 火力運轉費 시뮬레이션 모델

李鳳容,沈建輔 弘益大學校 1987 弘大論叢 Vol.19 No.2

A new probabilistic production costing simulation models have been developed based on the real economic load dispatch. Existing methodologies are based on the zero or maximum output in case of on-off two-state model, achieving only approximate economic loadings. Since the production costing is one of the most important part in the power system planning and operation, the model refinements are continuously required. The best model must be able to simulate the real world exactly and the computing efficiencies are also reasonable. In this sense, existing models can be said to be only approximate. The one using Monte-Carlo simulation may be exact, but the computing effort is generally tremendous. This paper proposes a new concept for the probabilistic production costing simulation. The key idea lies an the fact that the real economic load dispatch can only simulate the real world operation in power system. Two models, approximate and exact, have been developed. Results are compared with the available existing ones through sample systems, and the usefulness of the proposed methods is shown.

문주란과 아프리카문주란의 핵형분석

徐奉甫,李慶熙,金允景 慶北大學校 1992 論文集 Vol.52 No.-

The karyotypic analyses of Crinum asiaticum var. japonicum and C moorei var. album were carried out using conventional staining and Giemsa C-banding techniques, and distribution of B-chromosome was investigated. Chromosome compositions were diploid of 2n=22 in both species, of which five pairs including sat-chromosomes were submetacentrics, five pairs metacentrics and one pair subtelocentrics in C. asiaticum var. japonicum, but five pairs including sat-chromosomes were submetacentrics and the rest six pairs metacentrics in C. moorei var. album. Chromosome length was in a range of 5.6±0.4μm and 17.5±1.4 ㎛ in C. asiaticum var. japonicum, and 6.7±0.6㎛ and 15.8±4.7㎛ in C. moorei var. album. Consequently a little more variation in chromosome length was observed in C. asiaticum var. japonicum. Giemsa C-banding distribution of two species was very low, and thick C-bands were observed only near secondary constriction part of chromosome g. But there was a little difference in appearence of minor C-bands between two species, and this considered to be a characteristic of both species. B-chromosomes were observed only in C. asiaticum in a number of one to seven. But distinguishable morphological differences according to the different B-chromosome number were not observed.

電力시스템의 短期運用을 위한 火力-揚水發電시스템의 最適運轉

李鳳容,沈建輔 弘益大學校 1985 弘大論叢 Vol.17 No.2

Large-scale electric energy storage which is economically feasible is even today possible only with pumped storage hydro plant and its merit is increasing with the increased share of base units such as nuclear power and large capacity thermal units. However, in spite of its economy only a few methods or algorithms of optimal coordination between thermal and pumped storage plants could be found in literatures. This paper proposes quite a simple concept of pumping level and peak-shaving level which minimize the total operating cost. Cost functions which contain levels explicitly can easily be obtained and it is shown that the optimization is very simple. The proposed method is demonstrated through an example system of which peak load is 2,400 [MW] and has 10 generating units. Optimal solution has resulted the saving of 22,605,000 [Won] per day.