• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.3
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• pp.25-33
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• 2011

As chip operating frequency increases, there is growing concern about on-chip interconnect inductance. This paper presents a two-step inductance screening tool to select interconnects with significant inductance effects in a VLSI design. Test chips designed in different CMOS technology nodes are examined. The inductance screening results show that 0.1% of the nets in a design have inductance problems with chips running at its operating frequency, supporting the necessity of a screening process instead of adding inductance model to all the nets in the design. The increase in resistance due to geometry scaling will strongly affect the significance of inductance on delay as technology and frequency scale. Since higher frequency worsens inductance problem and geometry scaling alleviates it, inductance screening tool can provide useful guidelines to circuit designers.

• Nuclear Engineering and Technology
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• v.44 no.7
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• pp.735-744
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• 2012

In order to quantify the flow distribution characteristics of APR+ reactor, a test was performed on a test facility, ACOP ($\underline{A}$PR+ $\underline{C}$ore Flow & $\underline{P}$ressure Test Facility), having a length scale of 1/5 referring to the prototype plant. The major parameters are core inlet flow and outlet pressure distribution and sectional pressure drops along the major flow path inside reactor vessel. To preserve the flow characteristics of prototype plant, the test facility was designed based on a preservation of major flow path geometry. An Euler number is considered as primary dimensionless parameter, which is conserved with a 1/40.9 of Reynolds number scaling ratio. ACOP simplifies each fuel assembly into a hydraulic simulator having the same axial flow resistance and lateral cross flow characteristics. In order to supply boundary condition to estimate thermal margins of the reactor, the distribution of inlet core flow and core exit pressure were measured in each of 257 fuel assembly simulators. In total, 584 points of static pressure and differential pressures were measured with a limited number of differential pressure transmitters by developing a sequential operation system of valves. In the current study, reactor flow characteristics under the balanced four-cold leg flow conditions at each of the cold legs were quantified, which is a part of the test matrix composing the APR+ flow distribution test program. The final identification of the reactor flow distribution was obtained by ensemble averaging 15 independent test data. The details of the design of the test facility, experiment, and data analysis are included in the current paper.

• Membrane Journal
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• v.25 no.3
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• pp.276-286
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• 2015

The effects of relaxation and backwashing on fouling in ultrafiltration were investigated using full-scale membrane bioreactors (MBRs) which operated at a constant flux of 30 LMH. This paper also estimated the feasibility of using intermittent aeration strategies for minimizing the hydraulic resistance to filtration in comparison with the continuous aeration for running MBRs. Multiple cycles of filtration (14.5 min each) and relaxation (0.5 min each) were repeated. Similarly, a backwash was conducted by replacing a relaxation after each filtration cycle for the comparative performance test. The attached cake thickness on the membrane rapidly increased, caused by subsequent no aeration leading to easier combining with gel layer and the formation of heterogeneous layer on the membrane surface. During periodic backwashing, it is expected that gel and thin cake layer might sufficiently be removed by heterogeneous layer. After periodic backwashing, subsequent cake layer formation during time of no aeration was rapid than frequent no aeration, acting as a prefilter and preventing further irreversible fouling. Based on the Pearson correlation analysis, overall period fouling (dTMP/min) and average of all cycles (dTMP/min) were strongly correlated with the on-off period of aeration for operating MBRs.

• Journal of Biosystems Engineering
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• v.38 no.3
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• pp.171-179
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• 2013

Purpose: A simulator for the design and performance evaluation of a tractor with a hydro-mechanical transmission (HMT) was developed. Methods: The HMT consists of a hydro-static unit (HSU), a swash plate control system, and a planetary gear. It was modeled considering the input/output relationship of the torque and speed, and efficiency of HSU. Furthermore, a dynamic model of a tractor was developed considering the traction force, running resistance, and PTO (power take off) output power, and a tractor performance simulator was developed in the co-simulation environment of AMESim and MATLAB/Simulink. Results: The behaviors of the design parameters of the HMT tractor in the working and driving modes were investigated as follows; For the stepwise change of the drawbar load in the working mode, the tractor and engine speeds were maintained at the desired values by the engine torque and HSU stroke control. In the driving mode, the tractor followed the desired speed through the control of the engine torque and HSU stroke. In this case, the engine operated near the OOL (optimal operating line) for the minimum fuel consumption within the shift range of HMT. Conclusions: A simulator for the HMT tractor was developed. The simulations were conducted under two operation conditions. It was found that the tractor speed and the engine speed are maintained at the desired values through the control of the engine torque and the HSU stroke.

• Journal of the Society of Naval Architects of Korea
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• v.51 no.5
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• pp.419-428
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• 2014

This paper presents a numerical simulation method for the flow around advancing ships in regular waves by using a rectilinear grid system. Because the grid lines do not consist with body surface in the rectilinear grid system, the body geometries are defined by the interaction points of those grid lines and the body surface. For the satisfaction of body boundary conditions, no-slip and divergence free conditions are imposed on the body surface and body boundary cells, respectively. Meanwhile, free surface is defined with the modified marker density method. The pressure on the free surface is determined to make the pressure gradient terms of the governing equations continuous, and the velocity around the free surface is calculated with the pressure on the free surface. To validate the present numerical method, a vortex induced vibration (VIV) phenomenon and flows around an advancing Wigley III ship model in various regular waves are simulated, and the results are compared with existing and corresponding research data. Also, to check the applicability to practical ship model, flows around KRISO Container Ship (KCS) model advancing in calm water are numerically simulated. On the simulations, the trim and the sinkage are set free to compare the running attitude with some other experimental data. Moreover, flows around the KCS model in regular waves are also simulated.

• Steel and Composite Structures
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• v.1 no.4
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• pp.427-440
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• 2001

The growing use of unprotected or partially protected steelwork in buildings has caused a lively debate regarding the safety of this form of construction. A good deal of recent research has indicated that steel members have a substantial inherent ability to resist fire so that additional fire protection can be either reduced or eliminated completely. A performance based philosophy also extends the study into the effect of structural continuity and the performance of the whole structural totality. As part of the structural system, thermal expansion during the heating phase or contraction during the cooling phase in most beams is likely to be restrained by adjacent parts of the whole system or sub-frame assembly due to compartmentation. This has not been properly addressed before. This paper describes an experimental programme in which unprotected steel beams were tested under load while it is restrained between two columns and additional horizontal restraints with particular concern on the effect of catenary action in the beams when subjected to large deflection at very high temperature. This paper also presents a three-dimensional mathematical modelling, based on the finite element method, of the series of fire tests on the part-frame. The complete analysis starts with an evaluation of temperature distribution in the structure at various time levels. It is followed by a detail 3-D finite element analysis on its structural response as a result of the changing temperature distribution. The principal part of the analysis makes use of an existing finite element package FEAST. The effect of columns being fire-protected and the beam being axially restrained has been modelled adequately in terms of their thermal and structural responses. The consequence of the beam being restrained is that the axial force in the restrained beam starts as a compression, which increases gradually up to a point when the material has deteriorated to such a level that the beam deflects excessively. The axial compression force drops rapidly and changes into a tension force leading to a catenary action, which slows down the beam deflection from running away. Design engineers will be benefited with the consideration of the catenary action.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.30 no.3
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• pp.95-102
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• 2018

As a recent technical approach, a high-speed planing hull was tried to realize a friction reducing system by simultaneously actuating the triple streamlined step hull form in association with optimum speed of 35 knot planing for fishing boat. In this approach, the streamlined step hull form with triple structure of type was attached under the bottom of high-speed planing hull, while a friction resistance is reduced in the process of running at the speed of 35 knot. In addition, this research was to make a performance test as to the manufactured product and acquire the purposed values and the development items. Actually, after manufacturing the desired prototype of high-speed planing hull, the significant items, fuel efficiency (second) and amount of fuel consumption (degree) including maximum speed (knot) were estimated for a performance test. And tensile strength (MPa) and bend strength (MPa) as to the completed prototype like a high speed planing hull were also acquired during the test.

• The Korean Journal of Physiology and Pharmacology
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• v.25 no.6
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• pp.585-592
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• 2021

Cisplatin has been reported to cause side effects such as muscle wasting in humans and rodents. The physiological mechanisms involved in preventing muscle wasting, such as the regulation of AKT, PGC1-α, and autophagy-related factor FOXO3a by MuRF 1 and Atrogin-1, remain unclear following different types of exercise and in various skeletal muscle types. Eight-week-old male Wistar rats (n = 34) were assigned to one of four groups: control (CON, n = 6), cisplatin injection (1 mg/kg) without exercise (CC, n = 8), cisplatin (1 mg/kg) + resistance exercise (CRE, n = 9) group, and cisplatin (1 mg/kg) + aerobic exercise (CAE, n = 11). The CRE group performed progressive ladder exercise (starting with 10% of body weight on a 1-m ladder with 2-cm-interval grids, at 85°) for 8 weeks. The CAE group exercised by treadmill running (20 m/min for 60 min daily, 4 times/week) for 8 weeks. Compared with the CC group, the levels of the autophagy-related factors BNIP3, Beclin 1, LC3-II/I ratio, p62, and FOXO3a in the gastrocnemius and soleus muscles were significantly decreased in the CRE and CAE groups. The CRE and CAE groups further showed significantly decreased MuRF 1 and Atrogin-1 levels and increased phosphorylation of AKT, FOXO3a, and PGC1-α. These results suggest that both ladder and aerobic exercise directly affected muscle wasting by modulating the AKT/PGC1-α/FOXO3a signaling pathways regardless of the skeletal muscle type.

• Journal of the Korea Society of Computer and Information
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• v.24 no.4
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• pp.83-90
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• 2019

Is this paper, We propose to examined the relationship between advertising attributes and brand preference, consumer psychological repulsion, and consumer happiness. Due to the infinite competition between the companies, they are experiencing significant difficulties in operation. In this situation, effective advertising is obviously a very important means to overcome the difficulties of operation. Therefore, in order to maximize the advertising effect, sufficient awareness of the advertisement property and the production and exposure of the advertisement based on it can be very important. As such, the purpose of this study is to verify the effect of indirect advertising appearing on entertainment programs on consumers' preference for brands and their psychological resistance, and to verify the effect of consumers' preference for brands and psychological backlash on consumer happiness. In addition, the exposure pattern of indirect advertisement is intended to verify whether there is a control effect between the nature of the advertisement and the brand preference and psychological backlash. A total of 209 questionnaires were distributed to consumers who viewed program in order to achieve the purpose of this study. For empirical analysis, exploratory factor analysis, confirmatory factor analysis, frequency analysis, reliability analysis, structural equation model, and multimodal simultaneous comparison analysis were performed using SPSS V. 22.0 and AMOS V. 22.0. The results of the empirical analysis of this study are as follows. First, advertising attributes have a significant effect on brand preference. Second, the hypothesis that advertising attributes have a significant effect on psychological repulsiveness of consumers is partially adopted. Third, brand preference and psychological repulsion have a significant effect on consumer happiness. Fourth, we confirmed the moderating effect of PPL expression form in ad property, brand preference, and psychological repulsion. Based on these findings, we presented the implications, limitations and future research directions of the study.

• Korean Journal of Social Welfare
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• v.67 no.2
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• pp.33-60
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• 2015

The purpose of this study was to analyze the life experiences of fifteen marriage immigrant Asian women who went through running away from their home countries, marrying with Korean men, divorcing from their husbands, and coping with many difficulties after their divorce in Korean society. In order to conduct this study grounded theory methods have been employed. The central phenomenon digged out from this study was 'resistance to baffled reality' (i. e. dislocation). The causal conditions which brought about the central phenomenon were 'escaping for survival' and 'experiencing the gap between reality and expectation. 'The intervening conditions included 'getting to know the reality of their husbands,' 'losing hope,' and 'not being able to pull themselves together.' The contextual conditions consisted of 'being treated as maids,' 'becoming victims of family violence,' 'making up their minds to survive,' 'securing future life,' 'being marginalized,' and 'being aware of themselves as strangers.' The action/interaction strategies on the central phenomenon were 'building support systems,' 'building up will for new life,' and 'reconstructing social identity.'The final outcome was 'arranging places of new settlement.' The divorce was classified as four types: 'coping and growth,' 'emancipation and settling down,' 'being overwhelmed by livelihood,' and 'continuous wandering.' Based on these results, this study provided a few political and practice suggestions to prevent family violence and divorces among multi-cultural families, and also to bumper the impacts of divorce.