• Journal of Korean Library and Information Science Society
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• 제9권
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• pp.213-240
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• 1982

Today, one of the major pressures that libraries have been facing is the rapid growth of publications. Due to the rapid growth of publications, libraries have been faced the shortage of stack as well as quality deterioration of library collections. Naturally, these disa n.0, ppointed the users and made the present library activities weak and inadequate. One of the desirable actions in remedying these problems is to weed library collections properly and regularly. Weeding methods used in libraries are derived from the judgement by subject specialists, from the examining the imprint date and the past use patterns of a volume. Among these methods, the past use patterns are highly predictive of the future use, and can be used to create meaningful weeding criteria. Since the libraries in Korea have emphasized on numbers of library collection in the past, the libraries have neglected weeding library collections. Now, we must turn our concern toward the weeding library collections, and the attitude of the library services to the users must change from passive to active.

• Journal of Biosystems Engineering
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• 제39권1호
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• pp.11-20
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• 2014

Purpose: Walking type cultivator used for weeding generated excessive handle vibration as well as bouncing motion depending on the weeding speed. This research was conducted to define a design factor of the rotary weeding blades for reducing soil reaction forces as well as hand vibration. Methods: The motion and forces acting on the rotary blades were reviewed to find out the most influencing parameter on hand vibration. The installation angle (IA) of the blade was selected and analyzed to determine the condition of no reaction force less. For removing the unnecessary upward soil reaction, the design factor theory of weeding blade was suggested based on geometrics and dynamics. For evaluation of design factor theory, the experiment in situ was performed base on ISO 5349:1. The vibration $a_{hv}$ and theoretical value $X_{MF}$ were compared with two groups that one was positive group ($X_{MF}$ > 0) and the other was negative group ($X_{MF}$ < 0). Results: $X_{MF}$ was derived from rotational velocity, forward velocity, disk diameter, weeding depth, blade's width and IA of blade. Two groups had significant difference (p < 0.05). In aspect of the group mean total exposure duration, positive group was 17.53% bigger than negative group. When disk radius 100, 150 and 200 mm, minimum IAs were $4{\sim}27^{\circ}$, $3{\sim}15^{\circ}$ and $2{\sim}10^{\circ}$, respectively. A spread sheet program which calculated XMF was developed by Excel 2013. Conclusions: According to this result, minimum IA of weeding blade for soil reaction reduction could be obtained. For reduction hand-arm vibration and power consumption, minimum IA is needed.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제23권3호
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• pp.55-65
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• 1978

Upland weed control in Korea has been in dilema with the radical problems prior to weed problems, as it were, poor farming conditions, low yielding, no farmers concern, lack of political cares, and low returns for farming, etc. In these respects, the study was intended to collect all concerns to upland farming conditions and to array all research informations contributed upon Korea upland weeding, and at last interpreted its problems in order of importance. Especially expecting the reasonable and common use herbicides upon the most uplands in Korea, the crop compatibility and weeding efficacy by the most herbicides upon each crops were investigated from the experiment results. Among other interpretations of research results, the most important and first of all acceptance was for the direction and methods of weed research to be rationalized. And that weeding programs in level of upland farmers should be cautionsely and gradually propagated was interpreted to be accepted. Also, for the reasonable development of upland weeding situation in near future, the integrated promotion of upland farming rationalization is suggested by schematic explanations.

• Weed & Turfgrass Science
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• 제7권2호
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• pp.120-129
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• 2018

This experiment was conducted to find the most suitable crop establishment method and weed management practices for transplanted aman rice in Bangladesh. Rice variety Bangladesh Rice Research Institute (BRRI) dhan44 was used as planting materials where three crop establishment methods ($T_1$: direct wet seeding by drum seeder; $T_2$: hand broadcasting; $T_3$: transplanting) and four weeding options ($W_1$: Hand weeding (HW); $W_2$: BRRI weeder+HW; $W_3$: Herbicide+HW; and $W_4$: no weeding) were tested. Among the crop establishment methods, the highest grain yield ($5.12t\;ha^{-1}$) was obtained with the $T_3$, while the highest benefit cost ratio (BCR) of 2.08 was found in $T_2$. In case of the weed management method, $W_1$ showed superior results on the plant $density/m^2$ (139.66) at 60 days after transplanting (DAT), grain yield ($4.97t\;ha^{-1}$), and BCR (2.03). On the other hand, the highest plant dry matter (36.20 g) at 60 DAT and the highest yield ($6.10t\;ha^{-1}$) were obtained in a $T_3W_1$ combination. The results of this study show that the productivity of rice during aman season could be most significantly increased with the use of transplanting ($T_3$) alone, hand weeding ($W_1$) alone, or a combination of the two methods ($T_3W_1$).

• Journal of Biosystems Engineering
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• 제39권1호
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• pp.1-10
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• 2014

Purpose: This research was conducted to evaluate feasibility of a crank-type walking cultivators for weeding in furrowed upland. Methods: A walking cultivator developed by RDA was selected and evaluated with its working speed (S), cultivation depth (CD) and weeding performance (WP). The evaluation was performed in upland field on July and August, 2012. Also kinematic analysis of the machine was performed to draw out design improvements. Results: S in flat, uphill and downhill were about 0.11 m $s^{-1}$, 0.11 m $s^{-1}$, and 0.13 m $s^{-1}$ respectively. It was found that S had a low relevance with user conditions. The CD was 35 ~ 40 mm which was satisfied with the RDA guide for weeding machine. A wide variation was observed in values of WP depending on the growth stages of weeds and field conditions. The cultivator showed low performance in eliminating the well-grown weeds. Kinematic simulation revealed that high forward speed caused a high ratio of un-weeded area. Conclusions: The weeding performance of the cultivator was satisfactory for weeds in early growth stage but it showed difficulties in handling on up-slope and in entering up-land. Specifically, the weight of the cultivator was judged as overweight for female workers. The crank-hoe type cultivator was judged as unsuitable for small walking type machine due to weight of the four-bar linkage system. Kinematic analysis revealed that the ratio of crank speed to the ground speed must be 850 rpm s $m^{-1}$ (255 rpm based on 0.3 m $s^{-1}$) or greater to avoid uncultivated area. Selection of forward speed is a decisive factor in designing the weeding cultivator.

• Korean Journal of Medicinal Crop Science
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• 제24권3호
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• pp.183-190
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• 2016

Background: This study determined the effects of mulching, an environment friendly organic cultivation method, on antioxidant compound contents and growth in Codonopsis lanceolata, commonly known as Deodeok. Methods and Results: C. lanceolata was treated by mulching with several different methods (a non-woven fabric, biodegradable film, or rice husks) and also treated with hand weeding. A non-treatment plot was used as a control. The growth and levels of weed control in C. lanceolata were better in plants cultivated under mulching treatments (non-woven fabric, biodegradable film, and rice husks) than in those under non-mulching treatments (hand weeding and non-treatment). The contents of antioxidant compounds, such as total flavonoids, phenolics, and anthocyanins, were highest under the biodegradable film treatment, followed by the non-woven fabric treatment, rice husks treatment hand weeding, and non-treatment. There were identifiable differences in DPPH and ABTS activity in comparison to antioxidant compound content by solvent fractions. Mulching treatments resulted in higher DPPH scavenging activity in water and ethyl ether fractions and ABTS scavenging activity in n-butanol fractions than in other fractions, as opposed to hand weeding and non-treatment groups, although total activity of DPPH and ABTS did not increase with mulching treatments. Conclusions: Mulching C. lanceolata with biodegradable film and non-woven fabric is an effective method for improving plant growth and inhibiting the occurrence of weeds as well as for increasing antioxidant compound content and altering antioxidant activity.

• Korean Journal of Organic Agriculture
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• 제17권4호
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• pp.501-517
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• 2009

This research was carried out to study the effect of mulching materials and weed control methods on weed occurrence and growth of kale on upland and paddy soil of field culture at spring and autumn season. Paddy soil temperature of mulching treatments was high by $0.9{\sim}2.0^{\circ}C$ in comparison of non-mulching at autumn season. The control value of weed was over 91% at mulch paper and time required for weed control was reduced by 70% at mulch paper + machine weeding in comparison of non-mulching + hand weeding. The yield of kale was similar to that of conventional culture. Paddy soil temperature of mulch paper was higher on April, but lower on May and June than non-mulching at spring season. Dominant weed was Chenopodium album var. centrorubrum Makino, The control value of weed was over 91% at mulch paper, time required for weed control was reduced by 75% at mulch paper + machine weeding in comparison of non-mulching + hand weeding and the yield of kale increased by 34% than conventional culture. Dominant weed was Alopecurus aequalis var. amurensis Ohwi. on paddy soil at autumn season. The control value of weed was 43% at mulch paper. Time required for weed control was reduced by 80% at mulch paper + machine weeding in comparison of non-mulching + hand weeding. The yield of kale increased by 26% compared with than of conventional culture.

• Journal of Environmental Science International
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• 제24권2호
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• pp.253-260
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• 2015

Enlargement of street tree planting area is the proper and effective solution to reduce carbon dioxide. This solution bases on the ability of carbon storage and uptake by tree metabolism. However, the circumstance of road side has fatal disadvantages in tree metabolism such as growth and maturity because cutting and filling of roadsides cause unnatural soil composition. In this point, early rootage of street tree is the main factor of reducing carbon dioxide. This study aimed to find a appropriate transplantation planting method for sound and rapid rootage of street tree. For the study, Korean Mountain Ash(Sorbus alnifolia) were used for experimental groups. The groups were categorized by three groups such as trees produced on container with mulching treatment, trees produced in outdoor with mulching treatment, trees produced on container with weeding treatment. Each group consisted 10 trees with same size and transplanted in experimental site. Five months after transplanting, each group was estimated the biomass and carbon storage through a direct harvesting method. According to results of the study, the carbon storage of trees produced on container with mulching treatment is 42% more than trees produced in outdoor with mulching treatment. And the carbon storage of trees produced on container with mulching treatment is 19.5% more than trees produced on container with weeding treatment. These results may imply that transplantation of container produced tree with mulching treatment is the most rapid rootage among other groups. The weeding treatment is more effective than mulching treatment for rapid rootage of street trees.

• Journal of Biosystems Engineering
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• 제41권4호
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• pp.294-303
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• 2016

Purpose: This study aimed to evaluate the profitability of four selective mechanization systems in rice cultivation. Methods: Field experiments were conducted in the farmers' field during the wet season (June to November) of 2015 in Bangladesh. Mechanization systems were applied to evaluate four different selective levels (treatment) in eleven consequent operations. Seedlings were raised in a traditional seedbed and trays for manual and mechanical transplanting, respectively. Land preparation, irrigation, fertilizer, pesticide, carrying, and threshing and cleaning operations were performed using the same method in all the experimental plots. The mechanical options in the transplanting, weeding, and harvesting operations were changed. The mechanization systems were $S_1$ = hand transplanting + hand weeding + harvesting by sickle, $S_2$ = mechanical transplanting + Bangladesh Rice Research Institute (BRRI) weeder + reaper, $S_3$ = mechanical transplanting + BRRI power weeder + reaper, and $S_4$ = mechanical transplanting + herbicide + reaper. This experiment was performed in a randomized complete block design with four replications. Power tiller, rice transplanter, BRRI weeder, BRRI power weeder, self-propelled reaper, BRRI open drum thresher, and BRRI winnower were used in the respective operations. Accordingly, the techno-economic performances of the different technologies were calculated and compared with those of the traditional system. Results: The mechanically transplanted plot produced 6-10% more yield than the hand transplanted plot because of the use of tender-aged seedlings. Mechanical transplanting reduced 61% labor and 18% cost compared to manual transplanting. The BRRI weeder, BRRI power weeder, and herbicide application reduced 74, 91, and 98% labor, respectively. The latter also saved 72, 63, and 82% cost, respectively, compared to hand weeding. Herbicide application reduced the substantial amount of labor and cost in the weeding operation. Mechanical harvesting also saved 96% labor and 72% cost compared to the traditional method of harvesting using sickle. Selective mechanization saved 15-17% input cost compared to the traditional method of rice cultivation. Conclusions: Mechanical transplanting with the safe use of herbicide and harvesting by reaper is the most cost- and labor-saving operation. The method might be the recommended set of selective mechanization for enhancing productivity.

• Korean Journal of Weed Science
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• 제4권1호
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• pp.26-38
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• 1984

To investigate the varietal differences of weed competitive functions under the four different seeding and transplanting methods, rice cultivars, Milyang 23 and Sadominori, were used with the seven weeding methods, namely, weedy check, weed-free, once weeding at 3, 6, 9, and 12 weeks and two times weeding at 3 and 9 weeks after seeding/transplanting, respectively. As a result, the proper and reasonable weeding stages and times by total and respective weed group were estimated. Also the constructive characteristics for yield formations were evaluated under the different competitive conditions as affected by various cropping patterns.