• The Korean Journal of Physiology and Pharmacology
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• v.1 no.6
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• pp.741-748
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• 1997

In the present study, we have investigated the effect of metabolic inhibition on the inward rectifier K current ($I_{K1}$). Using whole cell patch clamp technique we applied voltage ramp from +80 mV to -140 mV at a holding potential of -30 mV and recorded the whole cell current in single ventricular myocytes isolated from the rabbit heart. The current-voltage relationship showed N-shape (a large inward current and little outward current with a negative slope) which is a characteristic of $I_{K1}$. Application of 0.2 mM dinitrophenol (DNP, an uncoupler of oxidative phosphorylation as a tool for chemical hypoxia) to the bathing solution with the pipette solution containing 5 mM ATP, produced a gradual increase of outward current followed by a gradual decrease of inward current with little change in the reversal potential (-80 mV). The increase of outward current was reversed by glibenclamide ($10\;{\mu}M$), suggesting that it is caused by the activation of $K_{ATP}$. When DNP and glibenclamide were applied at the same time or glibenclamide was pretreated, DNP produced same degree of reduction in the magnitude of the inward current. These results show that metabolic inhibition induces not only the increase of $K_{ATP}$ channel but also the decrease of $I_{K1}$. Perfusing the cell with ATP-free pipette solution induced the changes very similar to those observed using DNP. Long exposure of DNP (30 min) or ATP-free pipette solution produced a marked decrease of both inward and outward current with a significant change in the reversal potential. Above results suggest that the decrease of $I_{K1}$ may contribute to the depolarisation of membrane potential during metabolic inhibition.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.2 no.2
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• pp.1-5
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• 2001

One of the major advantages of using engineering plastics is ease of part assembly through a locking mechanism known as a snap fit. The typical snap fit involves a short cantilever beam with a projection at the free end. which slides over a one way ramp on the mating part to lock in place. The tightness of the mechanism is determined by the lateral interference of the two sliding members If too small they become loose and can't hold together. while if too large. excessive force can be generated. causing failure of the cantilever beam during the assembly operation. Therefore. the accurate determination of the force-deflection relationship for cantilever beams is a key element in snap fit design. And also. the process of injection molding should be considered when cantilever beam is designed. But it is not easy for novice designers to design them appropriately because of the profound knowledge related to injection molding. In this paper. an intelligent design program has been developed and proposed to improve a conventional empirical design method.

• Korean Institute of Interior Design Journal
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• v.24 no.6
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• pp.96-106
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• 2015

Occupying the center of architecture, design, painting and culture, minimalism is aesthetics of essence that reflects modern age but transcends age at the same time. Pursuing minimalist trend like this and covering the range of furniture, interior and architecture, total designer Antonio Citterio is developing minimalist designs of his own. Called one of the 3 greatest furniture designers in the world today, he leads the trend and enjoys high reputation as a world-renowned interior designer and architect. Therefore, the purpose of this study is to analyze and integrate minimalist descriptive characteristics which appeared in interior space of Citterio who pursues minimalist design. As a study method, this study reorganized minimalism from methodological perspective, drew out expressive characteristics of minimalist interior spaces unique to Citterio based on background and influence of Citterio's design and, centering on this frame of analysis, analyzed and integrated interior spaces he designed. The results of this study are as follows; first, in order to overcome problems that can become monotonous in a minimalist space, Citterio provides spatial experiences to feel visual and spatial variations using the ramp and bridge. Second, he created various senses of space with visual and spatial expansion using transparency in the walls made of glass. Third, with linear expressions, he designed modern spaces with beauty of proportion and balance through contrast and emphasis. Fourth, he made constructive expression through exposure of structures or stairs in the space. Fifth, he created sophisticated atmosphere with contrast between natural and artificial materials and emphasis of material properties. Sixth, his design also shows the characteristic of using furniture as the role of adjusting overall atmosphere of interior space, not as separated parts from it. The author hopes that above results of this study will provide new implications for the development of domestic interior design.

• Nuclear Engineering and Technology
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• v.19 no.4
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• pp.233-241
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• 1987

Difficulties are encountered when the behavior of complex systems (i.e., fuel failure probability) that have unreliable deterministic models is predicted. For more realistic prediction of the behavior of complex systems with limited observational data, the present study was undertaken to devise an approach of combining predictions from the deterministic model and actual observational data. Predictions by this method of combining are inferred to be of higher reliability than separate predictions made by either model taken independently. A systematic method of hierarchical pattern discovery based on the method developed in the SPEAR was used for systematic search of weighting factors and pattern boundaries for the present method. A sample calculation was performed for prediction of CANDU fuel failures that had occurred due to power ramp during refuelling process. It was demonstrated by this sample calculation that there exists a region of feature space in which fuel failure probability from the PROFIT model nearly agree with that from observational data.

• Journal of the Korean Institute of Rural Architecture
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• v.17 no.1
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• pp.113-120
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• 2015

In recent years, the population composition of rural area is changing due to the decreasing population growth of the aged with disability and people returning to farming. Since 1970's the rural community facilities have been spreaded out across most rural villages. Although the rural community facilities are the most widely used facilities, the existing facilities are need to be new built or remodeled according to demographic changes, usage of facilities, and environmental condition. Given this reality, the rural community facilities such as village assembly hall and nursing home for senior citizen are not only used for daily life place but also used like co-residence having meals and sleeping together. Therefore the rural community facilities have the potential to become welfare service space for rural elderly people. This research focuses on the current situation of universal design applied community facilities. According to the research, most of the village community facilities were built in the 1990s and 82% of the buildings were more than 15 years old. Furthermore, 45% of the village community facilities more than 15 years old most have a ground floor in masonry structure. The area of the building is 65% less than $100m^2$. The width of the access entrance, the height of the sink, gas safety valve and so forth were relatively well designed. However, the handrail of the entrance, space in front of the toilet bowl, the height difference between the entrance and floor, the installation of the width of the ramp and stair handrail was relatively incomplete. Village community facilities to be built in the future should be universal design fundamentally.

• Journal of the Microelectronics and Packaging Society
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• v.10 no.2
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• pp.19-26
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• 2003

Plastic and creep deformations of a solder joint on thermal cycle play an important role in the reliability of optical telecommunication components. Solder joint strain is increased with the thermal cycle time and it causes mis-alignments and power loss in the optical component. Furthermore, the component can be failed since the deformation exceed the limitation of the fatigue life. We applied the finite element analysis method to solve the problem of the solder joint reliability on thermal cycle. Plastic and creep deformations are calculated by the finite element method. And, the fatigue lire is predicted by using creep-fatigue prediction models with calculated strains. The temperature conditon of the analysis was referred from the Telcordia reliability schedule (-40 to 75). Also, the three ramp renditions, 1/min, 10/min and 50/min, and dwelling time were considered to analyze the differences of results.

• Tunnel and Underground Space
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• v.14 no.3
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• pp.188-202
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• 2004

If an underground research facility for the validation of disposal concept is constructed in KAERI, it is expected to have a thick weathered zone and varying surface topology. In this study, the influence of different geological conditions, tunnel slope, tunnel size, and sequential excavation is investigated by 3D mechanical analysis using FLAC3D. Around the tunnel, it is not expected to develop any plastic zone and the maximum stress might be as high as 5 ㎫. The maximum compressive stress will be developed at about 20 m to e dead end of the tunnel. There is no difference on stress and displacement distributions between the cases with and without sequential excavation. It is expected to have stress release in the roof and floor after the excavation of the tunnel. There is no significant influence of weathered zone size, tunnel size, and tunnel slope on the stress and displacement distributions. The modeling for the intersection shows the minimum factor of safety is above 3, when the in situ stress ratio K is 3. From the study, it was possible to demonstrate that the small scale disposal research tunnel in KAERI will be mechanically stable.

• Journal of Welding and Joining
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• v.17 no.1
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• pp.88-96
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• 1999

The effects of root gap on welding residual stress and deformation are dealt with the multi-pass weldment with three kinds(0, 6, 30mm) of root gap by F.E.M common code, and then compared with experiment data. In this analysis, an 100% ramp heat input model was used to avoid numerical convergence problem due to an instantaneous increase in temperature near the fusion zone, and the effect of a moving arc in a two dimensional plane was also included. During the analysis, a small time increment was applied in a period with instantaneous temperature fluctuation while a large time increment was used in the rest period. The residual stress is distributed as symmetric types and maximum value is also equivalent when the weldment with 0mm and 6mm root gap is welded. In the case of 30mm root gap welding, the distribution of the residual stress extends over a wide range as asymmetric types due to the built-up weld, and most of the residual stress is biased in the side of a built-up weld part. In case of 0mm gap welding and 6mm gap welding, a little angular distortion occurs, but the level of deformation is small. When the weldment with 30mm root gap is welded, the angular deformation of the asymmetric types, however, occurs larger than the other specimens. The experimental and the analytic results show good coincidence and indicate that the welding residual stress and deformation distribution of 30 mm root gap specimen may be asymmetric and the amplitude is larger than those of root gap specimen under standard.

• Korean Journal of Materials Research
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• v.2 no.2
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• pp.119-125
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• 1992

Oxygen segregation in horizontal-magnetic-field-applied Czochralski (HMCZ) silicon crystals has been studied as a function of magnetic field strength (B) and crucible rotation rate (C). Along the axis of 57mm din. <100> crystals grown under B=2, 3, 4 kG and C=4-15rpm, the oxygen distribution was usually saw-tooth shaped and fluctuated unevenly. Compared to the conventional CZ method, this result seems to indicate that the horizontal magnetic field, at levels used in the present experiment, had a destabilizing influence on oxygen transport to the growth interface. On the other hand, as C increased, the oxygen fluctuation lessened, and [0] increased overall. At B=2 kG, an oxygen profile in a level of 27-36 ppma was achieved by a programmed ramp of C. Oxygen precipitation behavior of the HMCZ silicon during a simulated device manufacturing process was compared and found to be inferior to that of typical CZ silicon. The uneven oxygen profile in the as-grown state was identified as the major source of poor precipitation uniformity in the HMCZ silicon.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.8 no.3
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• pp.187-196
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• 2014

This paper suggests linearity enhancement algorithm to Ensure safety of Mobile Walker on Slope. Mobile Walker happens to get off track due to external forces from Walker's weight and the degree of the slope while slope driving. In order to compensate this, this research used the controller that estimates the external forces according to the slope of road surface and adjusts it to the motor output. Also, through comparisons between targeted rotational angular velocity which the user inputs and its velocity of the robot, algorithm was applied which applies a weight to each shaft. As a result of applying the proposed correction controller, it diverges in case of non-compensation experiments that deviates when moving, but it case of applying the ramp calibration algorithm, the deviation distance at max was within 10cm that it keeps safe driving, and change rate of deviation distance was also stabilized after 1m where no more changes occurred.