• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.8
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• pp.16-21
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• 2007

CMOS variable gain amplifier (VGA) IC designs for the structure monitoring systems of the telemetries were developed. A three stage cascaded VGA using a differential amplifier and a linear-in-dB controller is presented. A proposed VGA is a modified version of a conventional VGA such that the gain is controlled in a linear-in-dB fashion through the current ratio. The proposed VGA circuit introduced in this paper has a dynamic range of 77 dB with 1.5 dB gain steps. It also achieved a gain error of less than 1.5 dB over 77 dB gain range. The VGA can operate up to 10MHz dissipating 13.8 mW from a single 1.8 V supply. The core area of the VGA fabricated in a Magnachip $0.18{\mu}m$ standard CMOS process was about $430{\mu}m{\times}350{\mu}m$. According to measurement results, we can verify that the proposed method is reasonable with regard to the enhancement of dynamic range and the better linear-in-dB characteristics.

• Journal of Korean Society of Steel Construction
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• v.23 no.3
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• pp.261-273
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• 2011

Recently, the demands for steel frame are increasing because of the trend and due to the demand for bigger and higher buildings. In the analysis of typical steel frame, connections are based on the idealized fixed or pinned connection. A fixed connection assumes that the relative angle of each member before deformation is the same after the transformation. Therefore, the stiffener reinforces the connection to sufficient rigidity and stability of the panel zone. In the economical aspect, however, the necessity of connection that the stiffener reinforcement has omitted is increasing due to the excessive production as well as labor costs of connection. In contrast, pinned connection is assumed that bending moments between the beams and columns do not transfer to each member. This is easy to make in the plant and the construction is simple. However, the structural efficiency is reduced in pinned connection because connection cannot transfer moments. The introduction of this semirigid process can decide efficient cross-sectional dimensions that promote ease in the course of structural erection, as performed by members in the field-a call for safety in the entire frame. Therefore, foreign countries exert efforts to study the practical behavior and the results are applied to criterion. This paper analyzes the semirigid connection of domestic steel by design specifications of AISC/LRFD and make data bank that pertain to each steel. After wards, the results are compared to those of idealized connection; at the same time, this paper presents a design method that matches economic efficiency, end-fixity, and rotational stiffness.

• Korean journal of communication and information
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• v.45
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• pp.7-48
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• 2009

The recent crises of Marxism do not mean Marx’s crisis. Marx said that he was not a Marxist. The purposes of this essay explore (1) the modern identity of the political economy; (2) the possibilities of mutual understanding between neoclassical economics and Marxist economics; (3) problems of the political economy in media and communication industry. I have begged for analytical Marxists, because of their good fruits. They accepted the methods of modern social science and they constituted a tremendous advance in the application of the scientific methods to the study of society. In insisting on micro-foundations(methodological individualism), analytical Marxism distinguished itself from structuralism and functionalism. I appreciate that analytical Marxism has reduced a theory to practice. But the works didn’t listen to everyone(from Marxists to un-Marxists), and explain everything. Making theory with production/consumption, macro/micro, and structure/behavior is a road to the political economy in the long run. It also applies to media and communication industry. The realm of media/communication is broad, which in philosophy, humanities, politics, economics, sociology, and engineering. And media policy is more complicated by politicians who look at the same situation from different angles. By the aid of interdisciplinary research, the political economy of media/communication shall explain at full length.

• Journal of the Korean earth science society
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• v.26 no.1
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• pp.41-57
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• 2005

The purpose of the study is to develop a educational data in order for students to perform geologic field survey effectively by themselves. A area around the Duta Mountain is selected. which is located at the southeastern part of Eumsung sedimentary basin because various rock types and geologic structures are well shown in this area and also it is convenient to reach there. Thirteen stops for observation are chosen m a route f3r exercising field geologic investigation. Data for field research are given and described in detail from each stop for observation. To do this, students make their own route map using general or digital geographic map and aerial photo is added to know relationship between large-scale structure and different rock types regionally. Moreover, it is designed to minimize conflict factors that may be experienced from the real field survey by showing outcrop photographs and polarizing photomicrographs of rut samples related to each stop and geologic structures. The attitude of students is investigated with the data of field geologic survey for students of an Earth Science class in the College of Education in Chungbuk National University. The results indicate that the educational data for geologic field survey brought positive changes that greatly help students perform field survey in definitive side, especially formation of absolute concepts on earth science.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.3
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• pp.177-190
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• 2017

This study investigates the effects of franchisors' characteristics including brand reputation, training and product related support, franchisees' characteristics including store location and management on the performance and recontract intention of franchisees in bakery franchise industry. Also, this study examine the moderating effect of CEO experience of franchisees among the franchisors' and franchisees' characteristics, and performance. To empirically test these relationships, data were collected from 386 respondents who are franchisees in the bakery franchise sector. In the verification of hypotheses, the structure equation modeling(SEM) is used. The results of this study are as follows. First, franchisors' brand reputation, training support, and franchisees' locational factor have significant effects on the financial performance of franchisees positively. However, franchisors' product related support and franchisees' management of the store have not significant effects on the performance. Second, the performance of franchisees has positive effect on the recontract intention. Third, the moderating effect of CEO experience is only significant in the relationship between franchisors' training support and the performance. Based on the findings, this study suggest the importance of building a good brand image and superior training system for franchisors to improve mutual ongoing growth. Also, franchisors should determine whether nascent franchisee entrepreneurs have CEO experiences to further improve performance. If they do not have related experiences, both opening and ongoing training supports of franchisors and the efforts of franchisees towards learning are required. Finally, this study suggest that both franchisors and franchisees should accurately analyze the conditions of possible locations and establish strategies to select beneficial location before starting a franchise business.

• Journal of Bio-Environment Control
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• v.3 no.1
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• pp.42-51
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• 1994

Visual features of a mushromm(Lentinus Edodes L.) are critical in sorting and grading as most agricultural products are. Because of its complex and various visual features, grading and sorting of mushrooms have been done manually by the human expert. Though actions involved in human grading look simple, it decision making underneath the simple action comes from the result of the complex neural processing of visual image. Recently, an artificial neural network has drawn a great attention because of its functional capability as a partial substitute of the human brain. Since most agricultural products are not uniquely defined in its physical properties and do not have a well defined job structure, the neuro -net based computer visual information processing is the promising approach toward the automation in the agricultural field. In this paper, first, the neuro - net based classification of simple geometric primitives were done and the generalization property of the network was tested for degraded primitives. And then the neuro-net based grading system was developed for a mushroom. A computer vision system was utilized for extracting and quantifying the qualitative visual features of sampled mushrooms. The extracted visual features of sampled mushrooms and their corresponding grades were used as input/output pairs for training the neural network. The grading performance of the trained network for the mushrooms graded previously by the expert were also presented.

• Journal of the Korean Society for Library and Information Science
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• v.41 no.1
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• pp.411-429
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• 2007

This study Performed five weeks' education on library use as a regular cultural subject at the target on university students and analyzed the difference in their library anxiety between Pre-education and Post-education as well as the difference in educational effectiveness based on the frequency of library use. The result intends to Present the result for basic materials which aye necessary for promoting the education on library use. The object of study selected the university freshmen. located in Gyeonggi-do, taking a lessen of cultural essential subjects. The education contents on library use were the understanding of library organization and function, the structure of library materials, the kind and use of academic information, the citation of materials, the description of bibliography, and the copyright in a library. The study methods applied in the study, were literature researches and two-times' questionnaire surveys in the first week of the education and the last week of that. Total 92 materials were applied for this study. This study performed faired t-test and independent t-test. As a result, four factors of six ones on library anxiety were selected in the verification of hypotheses after performing an education on university students' library use. In addition, the difference in education effectiveness based on university students' library use frequency was excluded in the course of hypothesis verification on six factors or library anxiety.

• Korean journal of applied entomology
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• v.34 no.3
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• pp.256-265
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• 1995

The effect ground-cover weeds on the occurrence of apple pests and their natural enemies was studied in an apple orchard in Ahnsung, Kyung-gi do during seasons of 1993 and 1994. The major apple pests and their parasitoids and predators were surveyed on the apple tree canopy in tow experimental plots; a weed-free lot where all weeds were removed by herbicide treatment, and a mowed plot where weeds were allowed restrictly by cutting with an asickle. Also, a sweep net sampling was taken from ground-cover weeds in the mowed plot. There were no significant differences in the abundance of mite and aphids between two plots, although mite densities tend to be lower in the mowed plot. The apple leaf miner, Phyllonorycter ringoniella, was significantly fewer in the mowed plot,. The densities of natural enemies of mites and aphids were slightly higher in the mowed plot. The parasitism of apple leaf miner in the mowed plot was 6~10% and 20~25% higher than that in the weed-free plot in 1993 and 994, respectively. Several natural enemies such as Apanteles kuwayamai (Braconidae), Orius sauteri (Anthocoridae), Chrysopa sp. (Chrysopidae), coccinellidae, and Eulophidae were collected both from weeds and the apple trees, However, potential apple pests were not observed on weeds. The development of insect community on the apple tree canopy was restricted by the pesticide spray on apple trees, while the insect community on weeds was maintained without significant destruction by pesticides spray on apple trees. Consequentely, the ground-cover weeds under apple trees affected occurrences of apple pests and their natural enemies in apple trees. te specialist natural enemies such as apple leaf miner's parasitoids dispersed from weeds to the apple canopy and affected apple leaf miner density significantly. However, generalist predators that have preys available on weeds stayed on weeds, hence their control effects for mites and aphids on the apple canopy were low.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.35-35
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• 2017

How do plants take up water from soils especially when water is scarce in soils? Plants have a strategy to respond to water deficit to manage water necessary for their survival and growth. Plants regulate water transport inside them. Water flows inside the plant via (i) apoplastic pathway including xylem vessel and cell wall and (ii) cell-to-cell pathway including water channels sitting in cell membrane (aquaporins). Water transport across the root and leaf is explained by a composite transport model including those pathways. Modification of the components in those pathways to change their hydraulic conductivity can regulate water uptake and management. Apoplastic barrier is modified by producing Casparian band and suberin lamellae. These structures contain suberin known to be hydrophobic. Barley roots with more suberin content from the apoplast showed lower root hydraulic conductivity. Root hydraulic conductivity was measured by a root pressure probe. Plant root builds apoplastic barrier to prevent water loss into dry soil. Water transport in plant is also regulated in the cell-to-cell pathway via aquaporin, which has received a great attention after its discovery in early 1990s. Aquaporins in plants are known to open or close to regulate water transport in response to biotic and/or abiotic stresses including water deficit. Aquaporins in a corn leaf were opened by illumination in the beginning, however, closed in response to the following leaf water potential decrease. The evidence was provided by cell hydraulic conductivity measurement using a cell pressure probe. Changing the hydraulic conductivity of plant organ such as root and leaf has an impact not only on the speed of water transport across the plant but also on the water potential inside the plant, which means plant water uptake pattern from soil could be differentiated. This was demonstrated by a computer simulation with 3-D root structure having root hydraulic conductivity information and soil. The model study indicated that the root hydraulic conductivity plays an important role to determine the water uptake from soil with suboptimal water, although soil hydraulic conductivity also interplayed.

• Applied Chemistry for Engineering
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• v.31 no.3
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• pp.310-316
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• 2020

Terpene-modified phenolic resins were used to improve the tires wet traction related to the driving safety and also rolling resistance related to fuel efficiency. In this work, alpha-pinene, beta pinene, and delta limonene resins, which constitute different basic structures of terpene-modified phenolic resins, were individually added to the tread compounds of tires and their physical properties were compared with those of the alkyl phenol resin compounds. Alkyl phenolic resins showed no significant difference in tangent delta from terpene-modified phenolic resins at 0 ℃, which is related to wet traction, but showed higher tangent delta at 80 ℃, which is related to rolling resistance, indicating smaller fuel efficiency improvement effects. Among the terpene-modified phenolic resins, beta pinene one showed improved wet traction and fuel efficiency compared to those of other resins. Delta limonene resin showed the best wet traction improvement effect, and alkyl phenolic resins showed relatively high tensile strength and abrasion property. All terpene-modified resins exhibited better rolling resistance than those of alkyl phenolic ones so that they can be said to have better fuel efficiency improvement effects and also to improve other properties compared to those of blanks. Terpene-modified phenolic resins could be used when mixing tire compounds referring to the properties of the phenolic resins revealed in this work, which could result in preparing compounds with improved wet traction and rolling resistance.