• Molecules and Cells
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• v.26 no.2
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• pp.212-215
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• 2008

The GC-rich discriminator sequence between the -10 region and the transcription start site of the rnpB promoter is responsible for stringent control of M1 RNA synthesis. The rnpB promoter also contains a G nucleotide at the previously identified transcription start site. In this study, we examined by mutagenesis of G to A whether this +1G nucleotide is involved in the stringent response. We found that the change did not alter the stringent response. Since the +1 mutation might alter transcription initiation, we compared the transcription start sites of the wt and mutant promoters by primer extension analysis. Surprisingly, we found that wild type rnpB transcription starts at both the +1G position (70%) and the -1C position (30%), and that the +1A mutation led to transcription initiation exclusively at the -1C position. We also generated two transversion mutations at the -1 position, both of which led to transcription starting exclusively at that position. The -1G mutant promoter gave a stringent signal similar to the wild-type, whereas the -1A mutant generated a significantly less stringent signal. Base on these results, we propose that a short sequence, up to 7 bp downstream of the -10 region, is involved in the stringent response of the rnpB promoter.

• Journal of the Economic Geographical Society of Korea
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• v.22 no.2
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• pp.178-195
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• 2019

In this study, we examine business start-up and closing business in a geographical context. In particular, we analyze the geographical characteristics of business start-up and closing business according to the type of industry. For the purpose, we use the last 10 years data that have been related with current economic situation since the financial crisis. In first, we identify the spatial distribution patterns of business start-up and closing business, We examine the difference between individual businesses and corporations. Finally, we construct general linear regression models and spatial regression models for them, and derive meaningful socioeconomic variables that explain their location distribution. The results of this study could provide basic data for regional planning of national and local governments that activate local economies as well as job creation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.12
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• pp.1836-1843
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• 2017

In this paper, we investigated fire cases those are believed to be caused by explosion of a electrolytic motor start capacitor. Using two types of commercially available electrolytic motor start capacitors, capacitor current and the possibility of capacitor explosion were tested. And the ignition possibility of the internal material leaked from a capacitor was also tested. In addition, experiments were conducted to see if the fire could spread when a capacitor was exposed to an external flame. From our test we observed that the current of the electrolytic motor start capacitor rose continuously to a certain level by product, if the capacitor was continuously energized with working voltage, and then the capacitor was exploded. The gas and liquid leaked from the capacitor by the explosion could ignite by an electric arc and an external flame. The capacitor current at explosion was different product by product, but each product had a certain current level at explosion. And the increase rate of the capacitor current until explosion was 24% and 31% for the products used in the experiment. We proposed the capacitor explosion prevention method that cuts off power when the capacitor current rises to a certain threshold level. The proposed method can be used if the current of the applied electrolytic motor start capacitor rises continuously and then the capacitor is exploded at a certain current level when the capacitor is energized continuously.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.4
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• pp.124-132
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• 2023

In order to support start-ups effectively with limited resources, it is necessary to provide support tailored to start-up companies. Businesses that are operating in local incubation centers may have different demands for the support depending on the region characteristics. This study was worked on companies that have entered into the incubation center 'Youth Cube', which is operated by Ansan City. We investigated the perception of importance in the field of support to identify support policy priorities, and the satisfaction level of each field of support currently supported. Then We conducted an IPA analysis to derive the direction of support. The Ansan area has regional characteristics that it is located in the metropolitan area with well-equipped start-up infrastructure and many innovative institutions, As a result of the importance survey, technology commercialization was recognized as the most important, and education/mentoring was recognized as the least important. Satisfaction with the space and facilities that can be used free of charge was the highest, and the satisfaction was the lowest for entrepreneurship education/mentoring, as was the degree of importance. In addition, according to each quadrant, we derived support that should be maintained, support that should be intensively improved, support that should be given a low policy priority, and support directions that should be kept in mind to avoid excessive support.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.4
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• pp.617-628
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• 2022

Ascon is one of the final round candidates of the NIST lightweight cryptography contest, which has been underway since 2015, and supports hash modes Ascon-Hash and Ascon-Xof. In this paper, we develop a MILP model for collision attack on the Ascon-Hash and search for a differential trail that can be used in a quantum setting through the model. In addition, we present an algorithm that allows an attacker who can use a quantum computer to find a quantum free-start collision attack of 3-round Ascon-Hash using the discovered differential trail. This attack is meaningful in that it is the first to analyze a collision attack on Ascon-Hash in a quantum setting.

• Tribology and Lubricants
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• v.33 no.4
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• pp.153-167
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• 2017

The aim of this study is to find the change in trend in the eccentricities of two journal bearings supporting the crankshaft of a single cylinder engine and the degree of misalignment of the shaft. We analyze the change in oil film thickness considering the wear scar under mixed-elasto-hydrodynamic lubrication regime at potential wear regions. For this, we first calculate the central eccentricities of the two journal bearings by using the mobility method. Then we calculate the outer end eccentricity by using the geometry of the bearings. Further, the tilting angle and degree of misalignment of the shaft are calculated by using the eccentricities of the two bearings. We show that the eccentricity of bearing #1, on which higher load is applied, increases at the beginning of the start-up cycle and during the coast-down cycle. However, the eccentricity of bearing #2, on which lower load is applied, decreases at the beginning of the start-up cycle and increases during the coast-down cycle. From the results of the analysis of oil film thickness, we show that the mixed-elasto-hydrodynamic lubrication regime for a misaligned shaft is at the initial stages of the start-up cycle for both bearing #1 and #2 and at the final stage of the coast-down cycle for only bearing #1.

• Proceedings of the KIEE Conference
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• 2008.04c
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• pp.19-21
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• 2008

The purpose of this paper is the optimal design of a single-phase LSPM(Line-Start Permanent Magnet Motor). A single-phase LSPM has a permanent magnet in the rotor that is same as induction motor. For that reason, magnet is operated by breaking torque in starting region and alignment torque in driving region. Therefore, we need the design process considering the trade-off relationship. In this paper, we propose the design process of a single-phase LSPM for a high starting torque and efficiency with equivalent circuit and FEM. And we use Taguchi Method for considering tolerance in manufacture. Finally, we compared the LSPM that is designed in this paper and conventional induction motor.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.1
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• pp.29-35
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• 2014

The purpose of this paper is the rotor design of a single-phase LSPM(Line-start permanent magnet) motor. A single-phase LSPM motor has a permanent magnet in the rotor that is same as induction motor. For that reason, magnet is operated by breaking torque in starting region and alignment torque in driving region. Therefore, we need the design process considering the trade-off relationship. In this paper, we propose the design process of a single-phase LSPM motor for a high starting torque and efficiency with FEM. And we use Taguchi Method for considering tolerance in manufacture. Finally, we compared the LSPM motor that is designed in this paper and conventional induction motor.

• Journal of Digital Convergence
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• v.12 no.12
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• pp.203-215
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• 2014

Although many studies about start-up existed, It is almost never shown study about ICT convergence start-up enterprise. This study tries to analyze success factor to start-up enterprise in rapidly growing ICT convergence area. Based on 10 entrepreneurial success cases, We figure out the total 29 units success factors utilizing ERIS model. We classify ICT commercialization with 4 types which are software-R&D centric, software marketing centric, software plus hardware R&D centric, software plus hardware marketing centric. Among success factors the most success factor is related entrepreneur;s ability and include major and professional knowledge about ICT's filed, insight through sensitivity about technical paradigm etc. It was derived the success factors indicated in the course of commercialization of ICT Covergence Unlike other forms of the existing start-up entrepreneurs and contributed to typified in four forms startups for ICT Covergence start-up entrepreneurs.

• Industrial Engineering and Management Systems
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• v.13 no.4
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• pp.421-431
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• 2014

The market basket data in the form of a binary user-item matrix or a binary item-user matrix can be modelled as a binary classification problem. The binary logistic regression approach tackles the binary classification problem, where principal components are predictor variables. If users or items are sparse in the training data, the binary classification problem can be considered as a cold-start problem. The binary logistic regression approach may not function appropriately if the principal components are inefficient for the cold-start problem. Assuming that the market basket data can also be considered as a special regression problem whose response is either 0 or 1, we propose three supervised learning approaches: random forest regression, random forest classification, and elastic net to tackle the cold-start problem, comparing the performance in a variety of experimental settings. The experimental results show that the proposed supervised learning approaches outperform the conventional approaches.