• Journal of Korean Society of Forest Science
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• v.98 no.6
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• pp.780-790
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• 2009

The objective of this study was to analyze 'Forestland Classification System' in Korea and to develop a strategy for its improvement. A survey was conducted in this study based on the Delphi technique, one of the interactive survey method relying on a panel of experts. The result indicated that the existing 'Forestland Classification System' was initiated for reasonable management of forestland, but now it turned into one of the most strict management restrictions. To improve forestland management in Korea, it was suggested to adopt 'Forest Function System' in this study. Moreover, to avoid indiscreet landuse conversion that might be occurred by substituting the 'Forest Function System' for the 'Forestland Classification System', it was suggested to adopt 'Forestland Conversion Propriety Assessment System'. In fact, landuse conversion has been regulated by the 'Environmental Impact Assessment System', but this system appeared inadequate to be applied to the forested area. Illegal acts for having permission of landuse conversion for reserved forests was another big issue in the forestland management. For example, alteration of the reserved status of forests or partition into patches smaller than the size limit has been attempted. Thus in this study, it was strongly recommended to take sanction against such illegal acts. In order to enhance the efficiency of forestland management, it was also suggested to integrate administrative agencies related to the landuse conversion or to take over the charge to local governments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.11A
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• pp.1661-1671
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• 2000

본 고에서는 한국통신(Korea Telecom) IMT-2000 시험시스템(이하: Trial system 라고 함) 단말기용 전력증폭단으로 적용하기 위한 다단구동증폭기 및 전력증폭기를 GaAs MMIC로 설계 구현하는 기술을 제시하였다. 설계된 구동증폭기는 3단으로구성하여 RF(Radia Frequency) 송신신호(1955$\pm$70MHz)대역에서 2단 (중간단)의 이득 조정범위가 40 dB이상이 될 수 있도록 능동부품인 MESFET를 Cascade 형으로 구성하고 MESFET의 게이트(gate)에 조정전압을 인가하는 증폭기를 설계하여 GaAs MMIC화 1 침(크기4$\times$5 mm)으로 제작하였다. 아울러, 본 논문에서는 제시한 구동증폭기는 동작주파수 대역폭 범위기 3.5배이고 출력전력은 15dBmm 이며, 출력전력이득이 25~27dB이고 반사계수는 -15~20dB이며 이득평탄도 3dB(동작주파수 대역폭내)로써 Trial system용 단말기의 최종단인 전력증폭단의 출력단 특성을 효과적으로 나타내었다. 그리고, 전력 증폭기는 2개의 입력단에서 출력되는 신호를 분배하는 전력분배기와 병렬구조인 4개의 증폭단에서 출력되는 출력신호를 외부에서 접속하는 전력결합기를 접소하여 구성하였으며 RF(Radio Frequency) 주파수(1955 $\pm$70NHz)에서 대역폭을 4배로 설계하여 광대역인 대역폭을 구현하였고 출력전력은 570mW이며, 출력부가효율(PAE; Power Added Efficency)가 -15$\pm$20dB이고, 이득 평탄도(Gain flatness)는 동작주파수 대역내에서 0.5dB이며 입출력 전압정재파비(Input & Output VSWR)가 13이하인 고출력 전력증포기를 GaAs MMIC화 1칩 (크기; 3$\times$4mm)으로 제작하였다.의 다양성이나 편리성으로 변화하는 것이 국적을 바꾸는 것보다 어려운 시 대가 멀지 않은 미래에 도래할 것이다. 신세기 통신 과 SK 텔레콤에는 현재 1,300만명이 넘 는 고객이 있으며. 이들 고객은 어 이상 음성통화 중심의 이동전화 고객이 아니라 신세기 통신과 SK텔레콤이 함께 구축해 나갈 거대란 무선 네트워크 사회에서 정보화 시대를 살아 갈 회원들이다. '컨텐츠의 시대'가 개막되는 것이며, 신세기통신과 SK텔레콤은 선의의 경쟁 과 협력을 통해 이동인터넷 서비스의 컨텐츠를 개발해 나가게 될 것이다. 3배가 높았다. 효소 활성에 필수적인 물의 양에 따른 DIAION WA30의 라세미화 효율에 관하여 실험한 결과, 물의 양이 증가할수록 그 효율은 감소하였다. DIAION WA30을 라세미화 촉매로 사용하여 아이소옥탄 내에서 라세믹 나프록센 2,2,2-트리플로로에틸 씨오에스터의 효소적 DKR 반응을 수행해 보았다. 그 결과 DIAION WA30을 사용하지 않은 경우에 비해 반응 전환율과 생성물의 광학 순도는 급격히 향상되었다. 전통적 광학분할 반응의 최대 50%라는 전환율의 제한이 본 연구에서 찾은 DIAION WA30을 첨가함으로써 성공적으로 극복되었다. 또한 고체 염기촉매인 DIAION WA30의 사용은 라세미화 촉매의 회수 및 재사용이 가능하게 해준다.해준다.다. TN5 세포주를 0.2 L 규모 (1 L spinner flask)oJl에서 세포간의 응집현상 없이 부유배양에 적응,배양시킨 후 세포성장 시기에 따른 발현을 조사한 결과 1 MOI의 감염조건 하에서는 $0.6\times10^6$cell/mL의 early exponential시기의 세포밀도에서 72시간 배양하였을 대 최대 발현양을 나타내었다. 나타내었다. $\beta$4 integrin의 표현이 침투 능력을 높이는 역할을 하나 이때에는 laminin과 같은 리간드와의 특이

• Radiation Oncology Journal
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• v.8 no.1
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• pp.73-77
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• 1990

From January 1981 to December 1989, total 42 patients with atelectasis from lung cancer were treated with radiation therapy at the Department of Therapeutic Radiology in Kyung Hee University Hospital. The reexpansion of atelectasis after radiotherapy of the lung was evaluated retrospectively, utillzing treatment records and follow-up chest radiographs. Of the patients with non-small cell carcinoma of the lung, the response rate was $62\%$ (21/34). Patient with small cell carcinoma showed a $75\%$ (6/8) response rate. There appears to be some evidence of a relationship of total tumor dose versus response of atelectasis; radiation dose over 40 Gy (1337 ret), had a favorable effect on the rate of response compared with that below 40 Gy (1297 ret), $70\%$(21/30) and $50\%$ (6/12), respectively (p<0.01). Total response rate (partial and complete responses) of all patients was $64\%$ (27/42). Franction size was not contributed to the difference of response rates between small fraction ($180\~200$ cGy) and large fraction (300 cGy), $53\%$ (14/22) and $65\%$ (13/20), respectively. The results of this study suggest that radiation therapy has a definite positive role in management of atelectasis caused by lung cancer, especially in inoperable non-small cell carcinoma.

• Journal of Mushroom
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• v.18 no.1
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• pp.95-99
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• 2020

The trade deficit in mushrooms has continued to increase in recent years. This study explored major issues and challenges faced by the mushroom industry to increase export, and to prioritize the current issues and challenges based on their relative importance. 11 major issues and challenges in the mushroom industry were highlighted in focus group interviews. Best-worst scaling analysis prioritized these major issues and challenges, and questionnaire surveys were completed by 31 mushroom industry experts. The results revealed that strengthening the mushroom quality and price competitiveness were the main priorities, followed sequentially by a diversification of the overseas export markets and stabilization of the domestic mushroom price.

• Education of Primary School Mathematics
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• v.23 no.4
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• pp.207-227
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• 2020

The demand for private education in Korea is steadily increasing every year, and the participation rate of private education is increasing as the grade goes down. In order to empirically verify the effectiveness of private education, it is necessary to analyze through longitudinal data that has been mainly investigated over a long period of time. This study investigated the longitudinal changes in mathematics academic achievement and participation time in mathematics private education using longitudinal data from 2013 (4th grade in elementary school) to 2017 (2nd grade in middle school) of the Seoul Education Longitudinal Study. The students were divided into groups in which mathematics academic achievement changed similarly as the grade went up, and the effect of mathematics academic achievement was examined according to the change of participation time in private mathematics education for each group. As a result of the study, it was found that the participation time of private math education of all students continuously increased from the 5th grade of elementary school to the 2nd grade of middle school, and the participation time of private math education by group was different. In addition, the effect of private tutoring by group was different according to the group.

• Journal of Embryo Transfer
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• v.16 no.2
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• pp.99-106
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• 2001

This study was undertaken to compare the efficiency of recovery rate and development rate of follicular oocytes collected either by aspiration or by slicing method. The follicular oocytes collected by the two methods matured in TCM199 supplemented with 10% steer serum at 39$^{\circ}C$ in a humidified atmosphere of 5% $CO_2$in air. After 22 h of culture, the oocytes were inseminated with frozen-thawed semen (2$\times$10$^{6}$ sperm/ml of final concentration) prepared with Percoll-density gradient in IVF-TALP medium for 16 h. Later, sets of 15 presumptive zygotes were transferred into 50 $\mu$L, droplets of CR1aa medium. On day 4 of the culture, embryos were transferred to TCM199 until day 9. The percentages of nuclear maturation to pre-metaphase II in the oocytes collected by aspiration are significantly (P<0.05) higher than that by slicing (83% vs. 62%, respectively). The mean number of oocytes recovered by slicing per ovary is significantly (P<0.05) higher than that by aspiration (15.1 vs. 6.7, respectively). Although the rates of cleavage and development to blastocyst of oocytes collected b)\\\\`aspiration are significantly (P<0.05) higher than that by slicing, the number of transferable embryos obtained by slicing method is significantly (P<0.05) higher than that by aspiration. From the results. we may conclude that slicing method is better than aspiration method for obtaining large number of transferable embryos per ovary.

• Research in Plant Disease
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• v.22 no.3
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• pp.168-177
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• 2016

A forecast model for estimating the infection risk of bacterial canker caused by Pseudomonas syringae pv. actinidiae on kiwifruit leaves in Korea was developed using the generic infection model of Magarey et al. (2005). Two-way contingency table analysis was carried out to evaluate accuracy of forecast models including the model developed in this study for estimating the infection of bacterial canker on kiwifruit using the weather and disease data collected from three kiwifruit orchards at Seogwipo in 2015. All the tested models had more than 80% of probability of detection indicating that all the tested models could be effective to manage the disease. The model developed in this study showed the highest values in proportion of correct (51.1%), probability of detection (90.9%), and critical success index (47.6%). It indicated that the model developed in this study would be the best model for estimating the infection of bacterial wilt on kiwifruit leaves in Korea. The model developed in this study could be used for a part of decision support system for managing bacterial wilt on kiwifruit leaves and help growers to reduce the loss caused by the disease in Korea.

• Tunnel and Underground Space
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• v.23 no.2
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• pp.150-159
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• 2013

It is generally well known that the stratification of thermal energy in heat stores can be improved by increasing the aspect ratio (the height-to-width ratio) of the stores. Accordingly, it will be desirable to apply a high aspect ratio so as to demonstrate the good thermal performance of heat stores. However, as the aspect ratio of a store increases, the height of the store become larger compared to its width, which may be unfavorable for the structural stability of the store. Therefore, to determine an optimum aspect ratio of heat stores, a quantitative mechanical stability assessment should be performed in addition to thermal performance evaluations. In the present study, we numerically investigated the mechanical stability of silo-shaped rock caverns for underground thermal energy storage at different aspect ratios. The applied aspect ratios ranged from 1 to 6 and the mechanical stability was examined based on factor of safety using a shear strength reduction method. The results from the present study showed that the factor of safety of rock caverns tended to decrease with the increase in aspect ratio and the stress ratio of the surrounding rock mass was influential to the stability of the caverns. In addition, the numerical results demonstrated that under the same conditions of rock mass properties and aspect ratio, mechanical stability could be improved by the reduction in cavern size (storage volume), which indicates that one can design high-aspect-ratio rock caverns by dividing a single large cavern into multiple small caverns.

• Korean Journal of Remote Sensing
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• v.31 no.2
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• pp.127-136
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• 2015

This study aims to quantify the stand-level above ground biomass in intact tropical rain forest of Brunei using airborne LiDAR data. Twenty four sub-plots with the size of 0.09ha ($30m{\times}30m$) were located in the 25ha study area along the altitudinal gradients. Field investigated data (Diameter at Breast Height (DBH) and individual tree position data) in sub-plots were used. Digital Surface Model (DSM), Digital Terrain Model (DTM) and Canopy Height Model (CHM) were constructed using airborne LiDAR data. CHM was divided into 24 sub-plots and 12 LiDAR height metrics were built. Multiple regression equation between the variables extracted from the LiDAR data and biomass calculated by using a allometric equation was derived. Stand-level biomass estimated from LiDAR data were distributed from 155.81 Mg/ha to 597.21 Mg/ha with the mean value of 366.48 Mg/ha. R-square value of the verification analysis was 0.84.

• Korean Journal of Medicinal Crop Science
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• v.6 no.4
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• pp.286-293
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• 1998

This study was carried out to find the effects of seed tuber position and number of nodes on growth of Saururus chinensis Baill. at experimental field of Chungbuk Provincial Rural Development Administration from 1996 to 1997. Seed tubers were divided into upper, middle and lower parts, and they were prepared to 1-, 2-, 3-node cuttings in each. Percentage of sprouting in planting of middle part was highest of 92%, and the percent increased by increasing the number of nodes. Growth of shoot and root tuber was the most favorable with planting of 3-node cuttings of middle part, and leaf area index (LAI) was highest of 3.10 in the same treatment. Dry matter weight and percentage of root tuber were highest of $821g/m^2$ and 28 % with planting of 3-node cuttings of middle part. Yield of dry leaf and root tuber were highest of 272kg/10a and 821kg/10a with planting of 3-node cuttings of middle part.