• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.6
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• pp.452-457
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• 2016

Single screw compressors are widely used in the fields of air/gas compression, refrigeration, and chemical fluid transportation systems. A single-screw compressor is composed of a screw rotor and two gate rotors located at both sides. This simple construction enables low rotational speed of the rotor, efficient compression with low noise, low vibration, and long bearing life. Despite these merits, the design method of single-screw compressors is not well known. To accelerate the industrial application of single-screw compressors, a design method using coordinate transformation is presented in this paper, and a tool trajectory is established for machining. Finally, the screw rotor, which is machined using the proposed method, is presented.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.1
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• pp.190-195
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• 2004

An exhaust brake system is composed of a gate valve, a pneumatic cylinder and an on-off solenoid valve. An on-off solenoid valve which is a key component of the exhaust brake system ought to have characteristics such as high reliability and long life for reducing the foot brake and tires damage, and for driver's fatigue relief of middle/large size vehicles running a long distance. In this paper, an on-off solenoid valve which is used for vehicle brake system was studied. For the performance evaluation of the on-off solenoid, electromagnetic characteristics and dynamic characteristics are analyzed. On the basic study for the performance improvement of exhaust brake system, pneumatic circuit and pneumatic valve of on-off solenoid type were suggested and the performance of pneumatic valve through the test procedure was evaluated.

• Journal of Sensor Science and Technology
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• v.31 no.1
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• pp.16-23
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• 2022

Cardiac disease is the most common cause of death worldwide. Therefore, detection and classification of electrocardiogram (ECG) signals are crucial to extend life expectancy. In this study, we aimed to implement an artificial intelligence signal recognition system in field programmable gate array (FPGA), which can recognize patterns of bio-signals such as ECG in edge devices that require batteries. Despite the increment in classification accuracy, deep learning models require exorbitant computational resources and power, which makes the mapping of deep neural networks slow and implementation on wearable devices challenging. To overcome these limitations, spiking neural networks (SNNs) have been applied. SNNs are biologically inspired, event-driven neural networks that compute and transfer information using discrete spikes, which require fewer operations and less complex hardware resources. Thus, they are more energy-efficient compared to other artificial neural networks algorithms.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.194-194
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• 2022

Recently, food-induced allergies have emerged as major global concerns. In the past ten years, it has doubled in western nations, and it has also increased in Asia and Africa. In many cases of food allergy, peanut allergy is prevalent, typically permanent, and frequently life-threatening. Therefore, we utilized gene editing techniques on the three major allergen genes in peanuts, Ara h 1, Ara h 2, and Ara h 3. Using gibson assembly and golden gate assembly, we created two vectors, the gRNA-tRNA array CRISPR-Cas9 system and Prime-editing. Using LBA4404 strain and agrobacterium-mediated transformation, the vectors were transferred to two elite Korean peanut lines. After co-cultivation and tissue culture, we extracted the tissue cultured peanut DNA amplified the hygromycin resistance gene and Cas9 gene in the T-DNA region. The integration of the T-DNA region into the host genome was demonstrated by the presence of a specific band in some samples. There have only been a few reported peanut gene editing studies. So, this study will contribute to peanut allergy and gene editing research.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.200-200
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• 2022

Recently, food-induced allergies have emerged as major global concerns. In the past ten years, it has doubled in western nations, and it has also increased in Asia and Africa. In many cases of food allergy, peanut allergy is prevalent, typically permanent, and frequently life-threatening. Therefore, we utilized gene editing techniques on the three major allergen genes in peanuts, Ara h 1, Ara h 2, and Ara h 3. Using gibson assembly and golden gate assembly, we created two vectors, the gRNA-tRNA array CRISPR-Cas9 system and Prime-editing. Using LBA4404 strain and agrobacterium-mediated transformation, the vectors were transferred to two elite Korean peanut lines. After co-cultivation and tissue culture, we extracted the tissue cultured peanut DNA amplified the hygromycin resistance gene and Cas9 gene in the T-DNA region. The integration of the T-DNA region into the host genome was demonstrated by the presence of a specific band in some samples. There have only been a few reported peanut gene editing studies. So, this study will contribute to peanut allergy and gene editing research.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.12
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• pp.209-218
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• 2012

Recently, the Field Programmable Stateful Logic Array (FPSLA) was proposed as one of the most promising system integration technologies which will extend the life of the Moore's law. This work is the first proposal of the FPSLA design automation flow, and the approaches to logic synthesis, synchronization, physical mapping, and automatic placement of the FPSLA designs. The synchronization at each gate for pipelining determines the x-coordinates of cells, and reduces the placement to 1-dimensional problems. The objective function and its gradients for the non-linear optimization of the net length and placement density have been remodeled for the reduced global placement problem. Also, a recursive algorithm has been proposed to legalize the placement by relaxing the density overflow of bipartite bin groups in a top-down hierarchical fashion. The proposed model and algorithm are implemented, and validated by applying them to the ACM/SIGDA benchmark designs. The output state of a gate in an FPSLA needs to be duplicated so that each fanout gate can be connected to a dedicated copy. This property has been taken into account by merging the duplicated nets into a hyperedge, and then, splitting the hyperedge into edges as the optimization progresses. This yields additional 18.4% of the cell count reduction in the most dense logic stage. The practicality of the FPSLA can be further enhanced primarily by incorporating into the logic synthesis the constraint to avoid the concentrated fains of gates on some logic stages. In addition, an efficient algorithm needs to be devised for the routing problem which is based on a complicated graph. The graph models the nanowire crossbar which is trimmed to be embedded into the FPSLA fabric, and therefore, asymmetric. These CAD tools can be used to evaluate the fabric efficiency during the architecture enhancement as well as automate the design.

• Journal of the Microelectronics and Packaging Society
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• v.24 no.1
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• pp.103-111
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• 2017

In this study, the thermomechanical stress and fatigue analysis of a high voltage and high current (3,300 V/1200 A) insulated gate bipolar transistor (IGBT) module used for electric locomotive applications were performed under thermal cycling condition. Especially, the reliability of the copper wire and the ribbon wire were compared with that of the conventional aluminum wire. The copper wire showed three times higher stress than the aluminum wire. The ribbon type wire showed a higher stress than the circular type wire, and the copper ribbon wire showed the highest stress. The fatigue analysis results of the chip solder connecting the chip and the direct bond copper (DBC) indicated that the crack of the solder mainly occurred at the outer edge of the solder. In case of the circular wire, cracking of the solder occurred at 35,000 thermal cycles, and the crack area in the copper wire was larger than that of the aluminum wire. On the other hand, when the ribbon wire was used, the crack area was smaller than that of the circular wire. In case of the solder existing between DBC and base plate, the crack growth rate was similar regardless of the material and shape of the wire. However, cracking occurred earlier than chip solder, and more than half of the solder was failed at 40,000 cycles. Therefore, it is expected that the reliability of the solder between DBC and base plate would be worse than the chip solder.

• Korean Journal of Construction Engineering and Management
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• v.11 no.3
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• pp.43-54
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• 2010

As Urban Regeneration is being carried out, stakeholders are most likely to have disagreements on their interests. Besides, dispersion of numerous communication routes and obscure decision processes aggravate the situation. Eventually, fragmented decision-making processes and complex structure lead to inefficient outcome and delay of projects. This paper is a study on decision-making support not only helps the program manager have more efficient and optimum decision, but also provides alternatives for Urban Regeneration. This study is conducted as follows. Firstly, the project process and the decision-making structure among stakeholders in Urban Regeneration are analyzed, and then the current status of decision-making in Urban Regeneration project is classified. Secondly, with literature study on "Gateway Review", the decision-making gateway review process in Urban Regeneration is defined, and then the "Gateway Review Elements" are listed. Thirdly, to establish gateway review process, this paper presents a check points, namely gate which supports a program manager to monitor and to control the program management in Urban Regeneration. Each gate has several supporting tools such as diagram of critical decision points relation, scheme of stakeholder, checklist. Fourthly, the proposed concept is verified by experts who have been carefully selected to provide their respective reviews. Finally, decision-making support gateway review system is modified based on their critiques and suggestions.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.23 no.1
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• pp.8-13
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• 2012

Objectives : Urocanase domain containing 1 (UROC1) has never been studied in prior studies on autism spectrum disorders (ASDs). UROC1 causes urocanic aciduria, one of the symptoms of which is mental retardation. The aim of this study was to investigate the association between the UROC1 gene and ASDs in a Korean population. Methods : A total of 258 control and 214 patients with ASD were used as subjects of this study. SNPs selected from UROC1 were genotyped using Illumina Golden-Gate Genotyping assay with VeraCode$^{(R)}$ technology. Statistical analysis was performed using SAS and Plink software. Results : We found no association of the 12 SNPs in the UROC1 gene with ASDs in a Korean population. Conclusion : Our study suggests that the 12 SNPs (11 SNPs and 1 SNP in the intron and 3'UTR region, respectively) in the UROC1 were not associated with ASDs in a Korean population. Further study on the exon region of UROC1 is needed.

• Journal of Veterinary Clinics
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• v.27 no.4
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• pp.378-381
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• 2010

The objectives in the present study were to evaluate the therapeutic effect of dioctahedral smectite (smectite) against piglet diarrhea caused by E. coli and Salmonella. Of this study, twenty piglets (body weight, $6.60{\pm}0.34\;kg$) with diarrhea were used to estimate the efficacy of smectite on piglet diarrhea with 20% smectite suspension in PBS. Pigs were administered with 1 ml smectite suspension three times a day after feeding, and fecal samples were collected at the gate of treatment and on 1st, 2nd, 3rd, and 4th day after administration. Changes in body weight, diarrhea index, and shedding of E. coli and Salmonella were monitored during the experimental period. The group treated with smectite reduced diarrhea index (p < 0.01), and increased body weight compared to control group. In the treated group, the number of E. coli and Salmonella was significantly decreased compared to each control group (p < 0.01). From results of the present study, 20% smectite suspension had therapeutic effect on diarrhea caused by E. coli and Salmonella in piglets.