• Korean Journal of Weed Science
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• v.5 no.2
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• pp.109-113
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• 1985

Experiments were conducted to know the ecology of injurious paddy field weeds, Scirpus hotarui and aneilema japonica in 1982-1983. Almost all emergences of the both species were on the soil surface in emergence depth. The vigorous growth stage was before Aug. 18, and the plant height and branch numbers were decreased and the days to flower were diminished by the shortday length treatment. A. japonica was not renewed by once cutting, but cutting S. hotarui on vigourous tillering stage was the most effective renew the growth and all of overwintered plants were renewed in emergence. The more these weeds emergence, the less rice yields.

• Design & Manufacturing
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• v.11 no.2
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• pp.46-50
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• 2017

EPS used in lost foam casting elastic modulus is extremely low. So it is necessary to derive machining conditions for effective cutting. Therefore this study were analyzed end-milling machining conditions to affecting the surface roughness of EPS foam. The machining conditions were set to depth, feed, and RPM at 3-level. And 18experimental conditions were derived using mixed orthogonal array. The most important condition for surface roughness is RPM. In addition, RPM machining condition range test that can realize surface roughness less than $10{\mu}m$ was performed. he range of RPM conditions is more than 15,000. However the range of RPM conditions is a condition that is difficult to use in actual field. In the future variance analysis and experiments are needed to derive the range of machining conditions available.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.57-57
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• 2017

Chrysanthemum is one of the most important floral crop in Korea produced about 7 billion dollars (1 billion for pot and 6 billion for cutting) in 2013. However, it is difficult to breed and to do genetic study because 1) it is highly self-incompatible, 2) it is outcrossing crop having heterozygotes, and 3) commercial cultvars are hexaploid (2n = 6x = 54). Although low-density genetic map and QTL study were reported, it is not enough to apply for the marker assisted selection and other genetic studies. Therefore, we are trying to make high-density genetic mapping using GBS with about 100 $F_1s$ of C. boreale that is oHohhfd diploid (2n = 2x = 18, about 2.8Gb) instead of commercial culitvars. Since Chrysanthemum is outcrossing, two-way pseudo-testcross model would be used to construct genetic map. Also, genotype-by-sequencing (GBS) would be utilized to generate sufficient number of markers and to maximize genomic representation in a cost effective manner. Those completed sequences would be analyzed with TASSEL-GBS pipeline. In order to reduce sequence error, only first 64 sequences, which have almost zero percent error, would be incorporated in the pipeline for the analysis. In addition, to reduce errors that is common in heterozygotes crops caused by low coverage, two rare cutters (NsiI and MseI) were used to increase sequence depth. Maskov algorithm would also used to deal with missing data. Further, sparsely placed markers on the physical map would be used as anchors to overcome problems caused by low coverage. For this purpose, were generated from transcriptome of Chrysanthemum using MISA program. Among those, 10 simple sequence repeat (SSR) markers, which are evenly distributed along each chromosome and polymorphic between two parents, would be selected.

• Journal of Biomedical Engineering Research
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• v.23 no.5
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• pp.351-364
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• 2002

Conventional 3D ultrasound imaging using mechanical ID arrays suffers from poor elevation resolution due to the limited depth-of-focus (DOF). On the other hand, 3D imaging systems using 2D phased arrays have a large number of active channels and hence require a very expensive and bulky beamforming hardware. To overcome these limitations, a new real-time volumetric imaging method using curved 2-D arrays is presented, in which a small subaperture, consisting of 256 elements, moves across the array surface to scan a volume of interest. For this purpose, a 2-D curved array is designed which consists of 90$\times$46 elements with 1.5λ inter-element spacing and has the same view angles along both the lateral and elevation directions as those of a commercial mechanical 1-D array. In the proposed method, transmit and receive subapertures are constructed by cutting the four corners of a rectangular aperture to obtain a required image qualify with a small number of active channels. In addition the receive subaperture size is increased by using a sparse array scheme that uses every other elements in both directions. To suppress the grating lobes elevated due to the increase in clement spacing, fold-over array scheme is adopted in transmit, which doubles the effective size of a transmit aperture in each direction. Computer simulation results show that the proposed method can provide almost the same and greatly improved resolutions in the lateral and elevation directions, respectively compared with the conventional 3D imaging with a mechanical 1-D array.

• The Journal of the Korea Contents Association
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• v.13 no.11
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• pp.477-491
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• 2013

In order to live up to public expectations, universities dedicate their best efforts to cultivating all Essential Competencies for outstanding individuals, especially reorganizing and improving their general education curricula and methods of teaching and learning, in light of the fact that a cutting-edge technology in a specific field does not bear a long span in the modern society. Through a Grounded Theory approach, the aim of this research is to study undergraduates' Experience Process of Action Learning designed to foster their Essential Competencies. With broadly selected 15 students from the courses for Essential Competencies, the method of theoretical sampling was employed so as to secure the diversity of the subjects' characteristics and backgrounds. After in-depth interviews, the data from the subjects were analyzed on the basis of Grounded theory approach of Strauss and Corbin. The conclusions of this analysis are as follows; Firstly, a learning coach should play a different role depending on the levels of Action Learning. Secondly, some time for introspection should be taken for the effective operation of Action Learning. Thirdly, learners ought to solve the problems faced during the learning process on their own. Fourthly, the aims of courses for Essential Competencies are also needed to be focused.

• Korean Security Journal
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• no.22
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• pp.113-144
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• 2010

Bioterrorism is becoming more attractive to terrorist groups owing to the dramatic increase in the utility and lethality of biological weapons in line with today's cutting-edge biological science and technology. The Republic of Korea is facing both internal and external terrorist threats, as well as the possible biological warfare by North Korea. Therefore, it is essential to establish an effective bioterrorism response system in the ROK. In order to come up with the adequate response system for the ROK, an in-depth study has been conducted on the current bioterrorism response system of the U.S. whose preparedness is considered relatively adamant. As a result, the following facts have been found: (1)the legislation with regard to bioterrorism has been established or amended according to the current situation in the U.S., (2)the counter terrorism activities have been integrated with the Department of the Homeland Security as the central agency in order to maximize the national CT capacity, (3)Specific procedures and instructions to cope with bioterrorism have been made into manuals so as to enhance the working-level response capabilities. Next, the analysis on the ROK's bioterrorism response system has been performed in various categories, including the legislation system, task role distribution, cooperative relations, and resource application. It turned out that the ROK's legislation basis is relatively weak and it lacks the apparatus to integrate the bioterrorism response activities on the national level. The shortage of the adequate response facilities and resources, as well as the poor management of manpower have also emerged as problems that hinder the effective CT implementations. Through an analytical and comparative study of the U.S. and the ROK systems, this paper presents several ways to ameliorate improve the current system in the ROK as follows: (1)establish the anti-terrorism law, which would be the basic legal basis for the bioterrorism-related matters; and make revisions to the disaster-related legislation, relevant to bioterrorism response activities, (2)establish an integrated body that has a powerful authority to coordinate the relevant CT agencies; and converge the decentralized functions to maximize the overall response capacity, (3)install the laboratories with a high biosafety level and secure enough of the strategic medical stock-pile, (4)enhance the ability of the inexperienced response personnel by providing with a manual that has detailed instructions.