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Crataegus pinnatifida Bunge is a deciduous tree belonging to the Rosaceae and native to Korea, China and Japan. In a previous study, Chinese C. pinnatifida showed the possibility to become a major ...

Division of Special Purpose Trees, Korea Forest Research Institute, Suwon 441-350, KoreaAbstract - Hovenia dulcis var. koreana Nakai, the oriental raisin tree, has been considered not only fruit but an herbal medicine in East Asia including Korea, Japan and east China. As honey plant, value of this species had been rising steadily. The aim of this study was conducted to develop the propagation technique by scion collection time, scion age and vinyl house on survival rate of H. dulcis . The survival rate by veneer grafting showed no significant differences among 3 new cultivars. The scion collection at the northern temperature zone was observed to be the most appropriate time before the spring equinox when the plants are fully dormant. Especially, the installation of vinyl house showed 86% survival rate by veneer grafting. The scion age was effective 1 year shoot than 2 years shoot for increase the grafting survival rate. In this case, the installation of vinyl house can contribute above 80%.

정금나무의 기능성 품종을 육성하기 위하여 정금나무 선발 5개체의 열매에 대한 항산화 활성을 측정하였으며, 항산화 성분인 총 페놀 함량을 측정하였다. 총 페놀 함량은 gallic acid를 기준물질로 하여 분석한 결과 15.8~19.9mg/g 범위로 전체 평균 17.9 mg/g을 나타냈으며, DPPH free radical 소거활성은 400 ppm의 농도에서 69.1~91.4% 범위로 전체평균 84.2%를 나타내었다. 환원력은 0.56~0.96 범위로 전체 평균 0.79를 나타내었다. 상관분석 결과 DPPHfree radical 소거활성과 환원력에서 상관계수가 0.969로 매우 높은 정의 상관관계를 나타내었다. Abstract: Vaccinium oldhamii Miq. is a Korean native tree, which is deciduous and shrub tree with broad leaf.To develop superior cultivars for edible or medicinal purposes, we evaluated total phenolic content andantioxidant activity. Total phenolic content was measured by folin-denis method and antioxidant activity wasmeasured by DPPH free radical scavenging activity (DPPH method) and reducing power (potassium ferricyanidemethod). Total phenolic content, DPPH free radical scavenging activity (at 400 ppm) and reducing power (at700 ppm) were 15.8~19.9 mg/g, 69.1~91.4% and 0.56~0.96, respectively. A linear correlation was shownbetween DPPH-radical scavenging activity and reducing power (r=0969). Key words

Aralia elata Seem. have a typical traditional significance among the wild herbs traditionally. Edible shoots of A. elata will augment consumer's interest due to its high value functional value, eco-friendly and pesticide-free produce. A. elata's root, fruit and bark are used as material of hypoglycemic agent and medicine for diabetes, kidney trouble, acute hepatitis, rheumation arthritis, stomach cancer and gastroenteric trouble. Flavonoid glycoside compound which is separated from A. elata's shoot shows high antioxidative activity. Also, root's identified active materials of antimicrobial was reported to be produced as food preservative and handy antimicrobial. Therefore, this research investigated quantitative morphological characteristics of leaves, spine and bud in naturally dominated and introducted A. elata in south Korea and then considered its principal compound analysis(PCA) and classification analysis(CA) among the 6 improved cultivars and 19 clones. PCA results showed that it show 76% accumulated explanation from four PC. The A. elata clones were classified into five groups; the first group of 15 clones including Yeongok, the second group of 5 clones including Yeoju, the third group of Bonghwa, Ulleung, the fourth group of Yongmunsa, Boseong and the fifth group of Singu. The object of this study will give us invaluable information about breeding by selection of A. elata in south Korea.

Vaccinium oldhami Miq. is a Korean native tree, which is deciduous and shrub tree with broad leaf. It grows 1~4m in height generally. Ecologically, this tree grows well in shady place even in barren soil. Also, the tree has resistance to cold and dry, which tend to form a little community. This research investigates quantitative morphological characteristics of leaf and fruit among the V. oldhami in South Korea and then considers its relationship on the basis of raw data among the 10 populations. This study will give us invaluable information about growing conditions, reasonable management and breeding by selection of V. oldhami in South Korea. The main results obtained from this study are summarized as follows; Leaf size of Mudeung population was larger than other populations. Naebyeon population was smaller in size of the leaf than other populations. Anmyeondo population was larger in fruit characteristics compared with other populations and Deogyu population was the smallest among populations. According to cluster analysis based on the leaf and fruit morphological characteristics, the natural V. oldhami populations were classified into four groups such as the first group of Kumo population, the second group of Mudeung population, the third group of Anmyundo, Daedun, Doolyun population and the fourth group of the other five populations.

A parallel induction motor drive with PWM inverter control has been developed for high-speed railway applications. This paper describes a re-adhesion control system to improve tractive efficiency and to reduce wheel abrasion. The adhesion characteristics of the high-speed train are analyzed to obtain the maximum adhesion effort and the re-adhesion control system is designed as a subsystem of induction motor control. In order to verify the performance of the proposed system, a downscaled re-adhesion control simulator is set up and running tests are executed.

This paper describes a re-adhesion control system for the Korean High-Speed Railway. To reduce the wheel abrasion and to improve traction efficiency, the adhesion characteristics between wheel and rail are analyzed. Also the re-adhesion control system is designed as a subsystem of induction motor control. In order to verify the performance or the proposed system, a downscaled readhesion control simulator is utilized. Both simulation and running test are executed and the results are evaluated.