• Tribology and Lubricants
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• v.34 no.1
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• pp.33-41
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• 2018

This paper describes a new test rig for identification of rotordynamic force coefficients of squeeze film dampers (SFDs) in automotive turbochargers (TCs). Prior studies have mainly concentrated on relatively large-sized SFDs used in aircraft engines, turbocompressors, and turbopumps. The main objective of the current study is to propose a test rig for identification of dynamic force coefficients of small-sized SFDs (a journal diameter of ~11 mm). The current test rig consists of a journal, a SFD cartridge, four support rods, an upper structure, a data acquisition (DAQ) system, and an oil circulation unit. The annular gaps between the journal outer surface and SFD cartridge inner surface create SFD film lands. The damper has two parallel film lands separated by a central groove, having an axial length and depth of 3 mm. Each film land has a length of 4 mm with a $40{\mu}m$ radial clearance. The static load and dynamic impact tests identify the structural characteristics (i.e., stiffness and natural frequency) of the journal and assembled test rig. The measurements show good agreement with predictions. The SFD performance data from this test rig will be used to develop innovative TC rotor systems with improved NVH and reliability characteristics incorporating advanced SFD technology.

• Journal of the Korea Safety Management & Science
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• v.17 no.4
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• pp.381-396
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• 2015

The study proposes multiple TRIZ contradiction solution strategies for addressing PC (Physical Contradiction) and TC (Technical Contradiction) by implementing TRIZ cause-and-effect tree. The problem associated with TC of the ends is solved by PC of means which employs a causal relationship between causes and effects. The TRIZ contradiction solution strategies demonstrated in this research are classified into 3 types of combined strategy as follows: 1. To-Be PC and AS-Is PC, 2.To-Be PC and As-Is TC, 3.As-Is PC and To-Be TC. The combined strategy of To-Be PC and As-Is PC is similar to a divide-and-conquer technique. This strategy adopts parallel strategies using 4 separation principles in time, in space, between parts and the whole, and upon condition of two reversed-PCs. Moreover, its application elucidates the conflict relationship of two TCs from the study. The integrated 4 separation principles and 40 inventive principles present an effective synergy effect from the combination, and further addresses the problems in the TRIZ contradiction resolution strategies. Combined strategy of To-Be PC and As-Is TC implements the 40 inventive principles that To-Be PC of the means resolves the As-Is TC of the ends. Combined strategy of As-Is PC and To-Be TC also uses inventive principles to the As-Is PC of the means to solve the To-Be TC of the ends. In addition, propositional and logical relationship of necessary and sufficient conditions between TC and PC is used to support the validity of 3 TRIZ contradiction solution strategies. In addition, 3 other strategies of necessary and sufficient conditions validate the contraposition relationship of the truth table. This study discusses TRIZ case studies from National Quality Circle Contest from the years between 2011 and 2014 to provide the usage guidelines of TRIZ contradiction solutions for quality purposes. Examining analysis from the case studies and investigating combined strategies allows the users to obtain comprehensive understanding.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.6
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• pp.578-585
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• 2003

The chum salmon (Oncorhynchus keta) is an anadromous fish distributed all around the North Pacific. Artificial production and release of the juveniles are being made by Korea, Japan, Russia, Canada and the United States. It is important to set up some criteria identifying each stock in order to clarify each nation's right of harvest for the chum salmon resource. As an attempt to build such criteria, we analyzed sequences of a microsatellite DNA Ogo5 and the COIII-ND3-ND4L region of the mitochondrial DNA from chum salmons of Korea, Japan, and the United States. Ogo5 has 4 different alleles: allele A, B-1, B-2, and B-3. Allele B-3 is found only in 3 individuals out of 12 Korea salmons. The Japan salmons have the other 3 alleles and the America salmons have only 2 allots, A and B-1. Heterozygosity index (Ho/He) distinguishes the Korea (1.61) and Japan salmons (1.63) from the America ones (1.09). Seventeen different haplotypes are found in the COIII-ND3-ND4L region from 60 individuals,20 from each stock. The gene genealogy of the haplotypes revealed by TCS program shows that the Korea and Japan salmons are genetically closely linked, but that they are clearly distinguished from the America ones. Ten and eleven individuals of the Korea and Japan salmons have an identical haplotype. Nine individuals of the Korea salmons $(45\%),$ however, are separable from the Japan salmons by their own specific nucleotides. This result presents usefulness of the COIII-ND3-ND4L region as a genetic marker for identification of the chum salmon stocks.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2D
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• pp.185-192
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• 2011

More practical outputs and insights can be obtained through transportation analysis considering the time-dependent traffic movements. This study proposes a method of constructing time-dependent O-D trip tables for expressway corridor using real-world individual trip data. In this study, time-dependent O-D trip tables for the nationwide highway network are constructed based on toll collection system data. The proposed methodology is to convert nationwide time-dependent O-D trip tables into Korean expressway corridor O-D trip tables in order to deal with the computational complexity arising from simulating a large-scale traffic network. The experiment results suggest that actual individual trip record data can be used to effectively construct time-dependent O-D trip tables. They also imply that the construction of time-dependent O-D trip tables for the national highway networks along with those for Korean expressway developed in this study would make transportation analysis more practical and applicable to real-time traffic operation and control.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.2
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• pp.392-397
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• 2006

This paper proposed yaw moment control scheme using braking and active rear wheel steering for improving driving stability especially in high speed driving. Its characteristics the unified chassis control system of two equipment that 4WS(4 Wheel Steering) and ESP(Electronic Stability Program). in this study the performance of the vehicle was compared each equipment. And conventional ABS and TCS can only possible to control the longitudinal movement of braking equipment and drive which can only available to control of longitudinal direction. There after new braking system ESP was developed, which controls both of longitudinal and lateral, with adding of the function of controlling Active Yaw Moment. On this paper, we show about not only designing of improved braking and steering system through establishing of the integrated control system design of 4WS and ESP but also designing of the system contribute to precautious for advanced vehicle stability problem.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.8
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• pp.1716-1721
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• 2005

Conventionally, 2WS is used for vehicle sleeting, which can only steering front wheel. In case of trying to high speed slalom or emergency through this kind of vehicle equipped 2WS, it may occur much of side slip angle. On the other hand, 4WS makes decreasing of side slip angle, outstandingly, so it is possible to support vehicle movement stable. And conventional ABS and TCS can only possible control the longitudinal movement of braking equipment and drive which can only availab to control of longitudinal direction. There after new braking system ESP was developed, which controls both of longitudinal and lateral, with adding of the function of controlling Active Yaw Moment. On this paper, we show about not only designing of improed braking and steering system through establishing of the integrated control system design of 4WS and ESP but also designing of the system contribute to precautious for advanced vehicle stability problem.

• International Journal of Highway Engineering
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• v.11 no.1
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• pp.25-36
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• 2009

Everyday congestion length (distance) and duration (time) data are collected and recorded in Expressway Traffic Information Center. These records are based on the information that the operators watch CCTV and decide traffic condition in order to present information about congestion on VMS. Using VMS message has some merits like that it doesn't need a great lot of cost to construct hardware such like FTMS because operators can check traffic condition by watching CCTV only. Of cause in the aspect of accuracy, using VMS message has the limitation that it is based on subject decision compared with FTMS. However, it can be said that the value of using VMS message is very large. The object of this study is to use the VMS information record (log file) usefully to provide information of traffic condition on expressway for users (drivers) without keeping the VMS information record in dead storage. To do so, in this research, congestion calculation method able to understand traffic congestion condition on expressway was developed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.8
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• pp.3326-3333
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• 2012

In this paper, an educational simulator of automobile chassis electronic control system was developed. The developed system is composed of three parts, a driving condition control & monitoring system, a chassis electronic system monitoring & analysis system, and a virtual simulator & educational multimedia contents. The driving condition control & monitoring system has a commercial real car simulator, hydraulic equipments for representing driving conditions, and a remote control and monitoring system. In the chassis electronic system monitoring & analysis system, information of various sensors and actuators applied to the system can be monitored by Labview programs. Finally, the suggested virtual simulator and the multimedia with 2D Flash and 3D animations can be used effectively by means of teaching materials.

• Applied Chemistry for Engineering
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• v.30 no.4
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• pp.472-478
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• 2019

A stable desalination method of the hardness substance such as $Ca^{2+}$ by controlling the total charge (TC) supplied to the membrane capacitive deionization (MCDI) cell was studied. The adsorption (1.5 V) and desorption (0.0 V) were repeated 30 times while varying the TC in the adsorption process. The concentration and pH of effluent, adsorption and desorption amounts, current densities and cell potentials were analyzed in the desalination process. The maximum allowable charge (MAC) of the carbon electrode used in MCDI cell was measured to be 46 C/g. As a result of operation at TC (40 C/g) below the MAC value, electrode reactions did not occur, resulted in the stable desalination characteristics for a long-term operation. When operating at TCs (50, 60 C/g) above the MAC value, however, the concentration and pH of effluent varied greatly. Also, the scale was formed on the electrode surface due to electrode reactions, and the electric resistance of the cell gradually increased. It was thus concluded that it is possible to remove stably the hardness substance without any electrode reactions by controlling the charge supplied to MCDI cell during the adsorption process.

• Korean journal of dermatology
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• v.56 no.10
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• pp.581-593
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• 2018

Atopic dermatitis (AD) is a common, chronic, relapsing, inflammatory skin disease that affects both children and adults. AD is the cause of considerable morbidity including severe pruritus and impaired quality of life. Treatments for active disease include avoidance of triggering factors, barrier repair, topical medications including topical corticosteroids (TCs) and topical calcineurin inhibitors (TCIs), phototherapy, antibacterial agents, and systemic immunosuppressants including cyclosporine. Until recently, the only Food and Drug Administration (FDA)-approved systemic treatment options for patients with moderate-to-severe AD were steroids and cyclosporine. Systemic steroids are not recommended by current guidelines and are commonly associated with disease rebound. Instead, clinicians choose from several off-label immunosuppressants. In 2018, the Korean FDA approved dupilumab for adults with moderate-to-severe AD whose disease is not adequately controlled with topical therapies. The implementation of treatment guidelines for AD is challenging. Herein, we review the several treatment modalities for AD and recommend a treatment algorithm.