소나무 林分의 材積生長率 推定에 關한 硏究 : 人工林을 中心으로 for the Artificial Forest

李鍾樂 慶熙大學校 1990 論文集 Vol.19 No.-

The purpose of this study was to estimate the stand yield in the future based on the measurement of the volume growth in the last 10 years. Surveyed forest stands were located at Yuhuing-Mach, Oita-Goon, Oita-Gen in Japan. The stand was composed of even-aged Japanese red pine(pinus densiflora) with artificial forest aged 23 years. The estimation of stand volume growth rate was conducted by taking out the core at the D.B.H. of the sampling trees measured in the sampling plots. The results obtained were as follows. 1) The regression between the diameter(D) and diameter growth(I^) was calculated to be I^=0.7286-0.0030D. 2) The estimated equation of confidence interval(S^2I^) of the diameter growth was S^2I^-0.06649(0.35372-0.04676D+0.00161D^2) 3) The equation for estimating tree height(H) from diameter was H-2.16237D^0.56320 with correlation coefficient(r_yx) of r_yx=0.98235, and standard error(s_yx) of s_yx=0.01055 in the main equation. The tree height table for Japanese red pine was prepared by using the above tree height equation. 4) The estimation of annual volume growth rate was 10.13% and the rate of estimated error was 12.30% 5) Total tree volume was 163.75㎡/ha. 6) Total annual tree volume growth was 16.58㎡/ha. 7) The range of annual tree volume growth was from 18.63㎡ to 14.40㎡/ha.

산화물피복에 의한 스텐레스강의 내식성향상에 관한 연구

李鍾樂,Y. Hayashi,林祐助,李鎭烈 한국표면공학회 1996 한국표면공학회 학술발표회 초록집 Vol.1996 No.-

薄板濾波器의 傳送特性

李鍾岳 한국항공대학교 1973 論文集 Vol.5 No.-

薄板傳送線의 傳送特性에 關한 解析이 考察되었다. S.B.Cohn에 依한 平行二薄板係의 解析은 結合係數等의 制限을 받는다. P.Shelton의 Off set 배열은 構造의 단순화 및 結合係數의 範圍를 容易하게 하였다. 本論文은 Shelton의 解析法을 多薄板構造로 확충시킨 것으로서 三薄板에서의 傳送特性이 特性 Impedance로 數式化 되었고 이는 다시 Mode Impedance를 決定함을 보였다. An analysis is made of the parallel coupled three strip transmission lines. S.B.Cohn, et al have deriven rigorous formulas and data on a pair of TEM mode excited, parallcoupled co-planar strips. However, since it has been known that the parallel co-planar strips provide only limited range of coupling factor, various attempts have been made to solve this problem. Among other works, P.Shelton's off-set arrangement shows competance both its simplicity of physical construction and range of coupling factor. Thispaper is prepared as a step to extend the concept of shelton's suggestion to a multi-strip configuration. As a canonical section of an off-set array, in this paperm three strips are arranged on two parallel planes between ground planes. The characteristics as a network are formulated in terms of the characteristic impedances which, in turn, are determined by mode impedances.

Ku-Band 3단 저잡음 증폭기의 성능개선에 관한 연구

李鍾岳 건국대학교 1994 學術誌 Vol.38 No.2

Low noise amplifier is designed with minimum noise figure for the development of LNBC. The conventional design method of low noise amplifier cannot be satisfied with optimum noise figure and low input, output VSWR at a time. Therefore, reflection coefficient should be selected that compromise between the noise figure and gain performance. It this paper, Ku-band 3-Stage law noise amplifiers are designed with low noise figure and low input, output VSWR simultaneously. The amplifier characteristics are simulated and optimized by using TOUCHSTONE. The resulting noise figure and the gain are 1.2dB and 28 dB respectively with the 15dB input resection.

이동표적 탐지용 Scanning Antenna

李鐘岳 건국대학교 부설 산업기술연구소 1987 논문집 Vol.12 No.-

Radio beam should be scanned to search the moving target. Such scanning ways are achieved by mechanical rotating of antenna unit or electronical rotating of radio beam only without any mechanical movement. Mechanical rotating need the driving portion and have some difficulties to drive the heavy antenna unit in the bad weather such as rain, snow, and strong wind. Especially in the moving vehicle, there is more restrictions in space and so on. Also any problem in the driving portion may be the cause of deterioration in reliability of antenna system. Consequently it has been studied to rotate the radio beam without mechanical rotating. As a result of such studies phased array antennas which use a lot of expensive phase shift elements were developed. But it is limited in special purpose such as military use which do not calculate the economic efficiency for the purpose of winning. Accordingly more economic method to scan the radio beam without mechanical movement by using ferrite phase shifter with simple structure was studied and beam scanning was confirmed by controlling the dc magnetic field around the ferrite rod.

De-embedding에 의한 FET의 s-parameter 추출 및 저잡음 증폭기에 관한 연구

이종악 건국대학교 1993 學術誌 Vol.37 No.2

In this paper, MIC amplifier using ATF13136 GaAs MESFET is characterized by means of de-embedding procedure, The range of measuring frequency is 6 to 7 GHz, and the bias is VDS = 2.5 V, IDS = 20mA, S-parameter of active device is extracted from MIC amplifier. Also, source lead inductance is extracted from the s-parameters. The s-parameter data sheet are compared with the obtained data. Compared with the data sheet, the obtained data show magnitude differences of 0.033 to 0.114.

잣나무 林分의 材積生長率 推定에 關한 硏究 : 人工林을 中心으로 For the Artificial Forest

李鍾樂 慶熙大學校 1992 論文集 Vol.21 No.-

The purpose of this study was to estimate the stand yield in the future based on the measurement of the volume growth in the last 10 years. Surveyed forest stands were the third block of Kyung Hee university experiment forest at the Toechon-myun, Kwangju-kun, Kyunggi province in Korea. The stand was composed of even-aged Korean white pine(Pinus Koraiensis S. et Z.) with artificial forest aged 22 years. The estimation of stand growth rate was conducted by taking out the core at the diameter breast high(D.B.H) of the sampling tress measured in the sampling plots. The results obtained were as follows. 1) The regression between the diameter (D) and diameter growth (I) was calculated to be I=0.75509-0.0050D 2) The estimated equation of confidence interval (S^2I) of the diameter growth was S^2I=0.01180(0.62249-0.08096D+0.00271D^2) 3) The equation for estimating tree height (H) from diameter was H=3.30408D^0.45073 with correlation coefficient (r_yx) of r_yx=0.92134, and standard error (S_yx) of S_YX=0.013 in the main equation. The tree height table for Korean white pine was prepared by using above tree height equation. 4) The estimation of annual volume growth rate was 10.3% and the rate of estimated error was 6.0%. 5) Total tree volume was 149.83㎥/ha. 6) Total annual tree volume growth was 15.43㎥/ha. 7) Total range of annual tree volume growth was frwo 14.51㎥ to 16.35㎥/ha. 8) Total volume of entire survey area (0.91ha) was 136.34㎥. 9) Total volume growth for annual of entire survey area was 14.04㎥.

훼라이트를 使用한 Y 接合 써큐레이터

李鍾岳 한국항공대학교 1975 論文集 Vol.8 No.1

마이크로波 固體能動素子로서의 훼라이트는 낮은 손실, 반복 속도등에서 우수성을 보인다. 本 論文에서는 環柱型 훼라이트를 使用한 Y 接合 써큐레이터의 理論的 解析을 보였다. 本構造의 경계조건에 적합한 Bessel함수와 GReen 함수를 구사하여 接合部의 傳送과 分離條件을 위한 최족의 훼라이트 반경을 구할수 있었다. 帶域幅은 反射係數로 定義하였으며 散?메이트릭스를 사용하여 整合 및 回轉條件을 구하였다. Theoretical analysis for the Y Juction Ferrite circulator is obtained. Using Bessel fuction wich is appropriate to the boundary condition and Green fuction, the optimum radius of ferrite cylinder can be obtained. Also the bandwith analysis and the matching condition for this structure is shown.

林分材積生長率의 推定法에 關한 比較硏究

李鍾樂 慶熙大學校 1988 論文集 Vol.17 No.-

To compare growth rates among Pressler's, Schneider's, and Meyer's method, volume growth and growth rates for the last 5 years at 37-year Pinus Koraiensis stand were calculated by each method, and the results are as follows; 1. Growth rates calculated by Pressler's Schneider's, and Meyer's method were 4.22%, 4.73%, and 4.81% respectively. 2. The field survey and calculation process by Pressler's and Schneider's method were simple and easy, yet Meyer's method required times in the field survey and calculation of growth rate. 3. There are many differences between growth rates calculated by the coefficients of Schneider's formula, so studies on the coefficients of Schneider's formula by species and diameters could be carried out. At present. therefore, Pressler's method is the most suitable method to calculate growth rate.

變分法을 使用한 週期構造의 임피단스 解析

李鐘岳 건국대학교부설 산업기술연구소 1978 논문집 Vol.4 No.-

The analysis is based on the variational method and equivalent network theory. The results calculated show that the mean slow wave factor is 10 and the slow factors at the upper and lower 5% of pass band are 50.