• Journal of The Korean Society of Grassland and Forage Science
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• v.44 no.3
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• pp.140-144
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• 2024

This study aims to contribute to resolving the critical issue of weed management in newly established alfalfa fields, study has been conducted on effective herbicide use. The study evaluated the impact of various domestically available foliar herbicides on alfalfa phytotoxicity, weed control, yield, and nutritive value. The experiment was designed in a randomized complete block design with four treatments. Alfalfa 'SW 5615' seeded in the spring of 2024 on a 1 ha field (March 18), with herbicide treatments including fluazifop-P-butyl (FPB), bentazone (BEN), and a mixture of these herbicides (MIX). Herbicide efficacy, alfalfa yield, and nutritive value were assessed 30 days post-application. Results indicated that the MIX treatment achieved superior weed control comparable to hand weeding (HW), although it exhibited higher phytotoxicity, requiring extended recovery periods. While MIX led to lower overall yield, it enhanced alfalfa purity, resulting in higher crude protein (CP) content and relative feed value (RFV) compared to other treatments. The study concludes that despite the potential for increased phytotoxicity, mixed herbicide treatments could offer a strategic advantage in enhancing the quality of alfalfa feed through effective weed management, thereby improving CP and RFV, critical factors for the nutritional value of alfalfa. These findings provide valuable insights for optimizing weed management practices in alfalfa cultivation, suggesting that mixed herbicide application, although associated with increased phytotoxicity on the plants, could improve the overall feed quality by reducing weed competition.

• Journal of Soil and Groundwater Environment
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• v.20 no.7
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• pp.135-147
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• 2015

Remediation of metal(loid)s-contaminated sites is crucial to protect human and ecosystem. Solidification and stabilization of metal(loid)s by the binder amendment is one of the cost-effective technologies. In this study, metal (loid)s in various field-contaminated soils obtained from steel-making, metal refinery and mining tillage were immobilized by the application of single binders such as diammonium phosphate (DAP), lime, and ladle slag. The efficiency of solidification and stabilization was evaluated by Toxicity Characteristic Leaching Procedure (TCLP) and the Standard, Measurements and Testing programme of European Union (SM&T) extraction processes. In terms of TCLP extraction, the binder was effective in order of lime > DAP > ladle slag. All binders were highly effective in the immobilization of Pb, Zn, Cu, Ni, and Cd. The increased immobilization efficiency is attributed to the increase in the Step III and IV fractions of the SM&T extraction. Lime and ladle slag were highly effective in the immobilization of the metal(loid)s, however, As release increased with DAP due to competition between the phosphate originated from DAP and arsenate. A further study is needed for the better immobilization of multi metal(loid)s using binary binders.

• Management & Information Systems Review
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• v.4
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• pp.137-159
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• 2000

Recently, the importance of ISP(Information System Planning) has been increased because of rapid change and severe competition in business environments. Furthermore, the role of IS in the organization has included not only the supportive activities but also the strategic activities. Organizations can get the competitive advantages through the strategic use of IT by establishing effective and systematic ISP implementation. The main focus of this study is investigate the relationship among three subunits(organizational factors, the role of IS and effective ISP) based on the contingent settings which the process of ISP is implemented. The reasons that conceptual framework of this study is based on the contingent theory are as follow: First, ISP process itself has a series of complicated work which various elements in a company are involved. ISP externally must have the process to evaluate information technology (technology related with IS). Internally ISP process has a serious of works including determining information requirements to develop successful IS for other functional departments and identifying strategic opportunity of IS aligned with business strategy. Secondly, the activity of ISP is occurring on the continual basis. Business environments in which ISP process has implemented are changing continuously. Specific ISP methodology which was appropriate in a certain period of time does not work any more because of the rapid changes in business environments. For this reason managers can hardly expect successful ISP without considering external environments or internal environments such as organizational or management side. For this study, 240 survey questionnaires were mailed and 71 questionnaires were returned. 57 samples were used for the final analysis and 14 samples were excluded from analysis in that they didn't exercise official and systematic ISP. As the result of analysis, among the internal factors(organizational size, time frame of decision making, budget, management style, organizational culture) organizational culture, management style and time frame of decision making are identified as contingent factors on the effective ISP. The result of this study may have meaning in suggesting the way to develop effective ISP through the formalization of business process, more favorable users attitude toward IS and selection of an appropriate ISP methodology.

• Korean journal of applied entomology
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• v.16 no.1 s.30
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• pp.7-12
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• 1977

In order to find out the optimum weeding date for growing barley in paddy field, several kinds of weeding dates and frequencies were made and compared. The results are summarized as follows: 1. As far as the weeding frequencies were fixed with one time, an immediate weeding after wintering resulted better barley grain yield and yield components by causing decreased yield of weed. 2. Maximum allowable date to be free from the weed competition were estimated as not late than February 10 or at most february 25. 3. It is considerable that the effect of weeding was continuously found till March 11 but no significant weeding effect was found when the weeding was done after April. 4. The competition of weed and barley was relatively so higher from February 25 to March 30 that the control during this period seemed to be very effective by causing little decrease in barley grain yield. 5. Major overdominant weeds observed in the paddy field for barley growing period were Alopecurus aequalis S., Stellaria alsine G., and Galium aparin L., in the order of degrees.

• Journal of Korea Game Society
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• v.15 no.1
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• pp.89-100
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• 2015

This study aims to figure out the impact of cross-promotion strategy on flow experience to overcome the restrictions of social network game. Social network games faces tougher market competition and shorter product life-cycles. The results show that the less users play games, the more they feel flow experience led by interests and self-expression of SNG. On the contrary, the more they play games, self- expression and sense of competition factor are proved to be effective factor for flow. Also Users' cognition for usefulness and annoyingness of cross- promotion are different according to level of game uses and promotion uses. People who play games more and utilize promotion more appreciate the usefulness of promotion and indulge in flow experience of SNG.

• Journal of Engineering Education Research
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• v.13 no.1
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• pp.70-77
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• 2010

The purpose of this study was to verify the educational value of student portfolio and to give the direction of making student portfolio. Qualitative research method was used to accomplish objectives of the study. 9 students who were winner in competition of student portfolio in I University at Incheon Province were interviewed. Data were recorded, transcribed and analyzed. Most students started to make student portfolio by compulsory, but they realized that it was necessary to start student portfolio from the lower grades. They had difficulties in not having materials of activities and hesitated at the beginning of making student portfolio even though they got standard form from the university. Students recognized that making student portfolio was effective tool because it could enhance self-reflection, awareness of importance of record, preparation of future, obtaining of motivation for anonther activities, getting self-confidence, and improvement of writing skill.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.2 no.2
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• pp.53-61
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• 1999

This study was conducted to determine the optimal collecting time and methods of utilization of forest topsoil as a seed-bank source for revegetation materials of slopes. From April to November of 1998, nursery seedbeds in the greenhouse of Seoul National University were seeded with mixtures of forest topsoil and seeds. The nursery seedbeds were treated to evaluate the effect of depths of forest topsoil and seeding amounts. Seasonal experiments with $3{\times}3$ factorial design were conducted in April, June and August. More than 40 seedlings/$m^2$ were observed as the naturally-emerged species in the plot, treated with the top-layer forest soil within the depth of 10cm. However, it was found, as seeding more seeds, the number of appearance of the naturally-emerged species reduced because of the heavy competition between the seeded and the naturally-emerged. According to the results of this research, it is recommended that seeding amount should be no more than 1,000 seeds/$m^2$ to avoid the severe competition. Also it was observed that the forest topsoil collected in spring(April) is better than that collected in summer. The more species of the naturally-emerged were found in the forest topsoil collected in spring. Forest-topsoil-mixed-materials as a seed-bank source could significantly increase the plant diversity and productivity. Effective use of forest topsoil as a seed-bank source may become a valuable tool in future restoration of disturbed slopes for promoting plant community diversity and recycling of spoiled-soils from the slopes.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.12
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• pp.2765-2772
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• 2015

In Korea MVNO was introduced in 2011 when twenty seven years had passed since Korea Mobile Telecom(now SK Telecom) started mobile phone service. MVNO can make competition more effective to lower communication costs through the alternatives. In the early 2000s, the need for the introduction of the MVNO has been raised already by scholars in Korea. But it wasn't until the late 2000s when rate cuts appeared to be a major policy issue, and Korean government introduced MVNO. In April 2015, MVNO's market share reached 8.8%, but Korea does not have a firm system yet. This rapid growth of MVNO market in Korea was made possible by consumers' demand for cheaper services and late introduction of MVNO. And telecom companies(MNO) abuse their supreme power against small and medium firm MVNOs and reserved market share using their subsidiary companies. Thus proper regulation is necessary. However, the government authorities should have recognized global MVNO flow quickly and have to make a sufficient effort to establish proper competition condition of the mobile telecom market.

• BMB Reports
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• v.30 no.5
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• pp.326-331
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• 1997

To construct a competitive ELISA standard curve for the detection of glucose-6-phosphate debydrogenase (G6PD), we used highly purified native G6PD (nG6PD) as both immobilized and soluble antigens and anti-G6PD serum raised against nG6PD as antibody. The polystyrene cuvettes coated with nG6PD were challenged with a mixture of a limiting amount of anti-G6PD serum and various doses of nG6PD as competitors followed by incubation with alkaline phosphatase-anti-IgG conjugate. The competitive ELISA did not exhibit the typical sigmoidal dose-response curve characteristic of competition immunoassays under the optimal concentrations of antigen and antibody. The soluble nG6PD used as competitor failed to effectively inhibit the binding of antibodies to the immobilized nG6PD. The addition of NADP, a cofactor of G6PD enzyme, to coating buffer used for immobilizing nG6PD to the cuvettes and PBS-Tween-BSA buffer for diluting competitors did not improve the inhibition of antibody binding to immobilized nG6PD by soluble n/G6PD. The addition of BSA to coating buffer did not increase inhibition, either. Surprisingly, when partially active G6PD (paG6PD), obtained by repeated freeze-thawing, was used as competitor, the antibody binding to either immobilized nG6PD or immobilized paG6PD was inhibited 49-58%. We conclude that an effective competitive ELISA system with nG6PD enzyme and anti-G6PD serum for the detection of G6PD may not be established due to the poor inhibition of antibody binding to immobilized nG6PD by soluble nG6PD under the present assay conditions and that the inhibition may be improved by using an inactivated enzyme as competitor regardless of the type of immobilized antigen used. These results imply that the immobilized nG6PD may undergo denaturation upon binding to the polystyrene cuvettes and that our anti-G6PD serum may recognize denatured enzyme better than active enzyme.

• Journal of Forest and Environmental Science
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• v.34 no.1
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• pp.66-70
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• 2018

Preliminary investigation and analysis of the effectiveness of controlling the number of ecosystem disturbance fishes residing in Togyo reservoir using the native carnivorous fish species were performed. The data were collected from August 2011 to November 2016. The release of native carnivorous fish species was carried out from the end of May, 2012 to the end of July, 2016, considering fishing ban period of Siniperca scherzeri. The comparative abundance of Lepomis macrochirus was found to be 12.8% in the first year and increased a little bit after releasing the native carnivorous fish. However, it decreased to 3.9% in the last year showing a value of less than 5%. On the other hand, the Micropterus salmoides populations tended to increase after the release of native carnivorous fish species. This seems to be the result of the segregation of habitat by interspecific competition with S. scherzeri. The M. salmoides moved from inside of the lake to edges, and to influent tributaries. Stable isotope analysis showed that Channa argus had the highest levels of nutrition, S. scherzeri and M. salmoides were in competition, and L. macrochirus was used as a feed source for released species. Changes of the fish community in the Togyo reservoir was represented by the rank abundance curves based on the results of the fish fauna. As a result, the fish group in incoming tributaries are somewhat disturbed after the release of the native carnivorous species. Similarly, the fish group in the reservoir were disturbed as well but it's gradually stabilizing afterwards. Therefore, the control of the ecosystem disturbance species using the native carnivorous fish of Korea is effective and helps to stabilize the fish community in the lake.