• Journal of the Microelectronics and Packaging Society
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• v.23 no.4
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• pp.25-29
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• 2016

The semiconductor industry has been developed mainly by micronization process due to many advantages of miniaturization of devices. Mass production of semiconductors of 10 nm class has been started recently, and it is expected that the technology generation of 5 nm & 7 nm technology will come. However, excessive linewidth reduction affects physical limits and device reliability. To solve these problems, new process technology development and new concept devices are being studied. In this review, we introduce the next generation technology and introduce the advanced research for the new concept device.

• Clinical and Experimental Reproductive Medicine
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• v.2 no.2
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• pp.41-46
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• 1975

Careful scruting of the data indicate that malnutrition actually limits fertility. Spermatogenesis may likewise be impaired by inadequate diet, particularly one that is very poor in protein. For those who are underweight, increased caloric intake stressing high protein content is recommended. Included are supplementary vitamins, particularly B complex, which stimulate the appetite. Injudicious dieting by the woman to conform to current standards of beauty may also result in malnutrition. This contributes to faulty oogenesis and, in extreme dieting, may produce a long-standing amenorrhea. Obsity may also reduce fertility. Since most cases of obesity are due to over-eating, the full cooperation of the patient must be enlisted. And no device is effective for breaking up fatty deposits. Instead, a program of exercise is recommended. The treatment of both malnutrition and obesity is directed toward general dietary habits either weight gain or weight reduction, with a well balanced high protein diet.

• Journal of the Korean Operations Research and Management Science Society
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• v.31 no.2
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• pp.129-140
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• 2006

Quantity Flexibility contract coordinates individually motivated supplier and buyer to the systemwide optimal outcome by effectively allocating the costs of market demand uncertainty. The main feature of the contract is to couple the buyer's commitment to purchase no less than a certain percentage below the forecast with the supplier's guarantee to deliver up to a certain percentage above. In this paper we refine the previous models by adding some realistic features including the upper and lower limits of the purchase. We also incorporate purchase and canceling costs in a cost function to reflect the real world contracting process more accurately. To obtain the solution of the model, we derive a condition for extreme points using the Leibniz's rule and construct an algorithm for finding the optimal solution of the model. Several examples illustrating the algorithm show that the approach is valid and efficient.

• Architectural research
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• v.24 no.2
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• pp.53-61
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• 2022

Irregularities in the structure are crucial factors in screening structural vulnerability under extreme loadings. Numerical analyses were carried out considering wind and seismic loadings for four structures with discrete irregularity: continuous and discontinuous beams with varied story levels, and L-shaped irregular buildings. Structural responses such as maximum displacements, bending moments, axial forces, torsions, and story drifts are evaluated as per the criteria and limits defined by ACI 318. The outcomes indicate that the frame system with beam discontinuity on the upper half of the height exhibits the best structural performance. The results also indicate that the asymmetrical design of the L-shaped model makes it more susceptible to damage when subjected to strong lateral loading conditions.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.4
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• pp.402-413
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• 2022

Objectives: In this study, the scale of exceeding the extreme heat exposure standard at the construction site was estimated using the nationally approved statistical data and wet bulb globe temperature modeling method. By comparing and analyzing the modeling results with the existing work environment monitoring results, the risk of heat exposure at outdoor construction sites was considered. Methods: Using the coordinates of second level administrative districts and meteorological observatories as the key, the automated synoptic observing system data and building permit data for 2021 were matched. The wet-bulb temperature was obtained using Stull's formula, and the globe temperature was obtained using the Tg_KMA2006 model. WBGT was calculated using these. Excess rates were obtained compared to exposure limits for heavy work-continuous work and moderate work-25% rest. It was compared with the results of the work environment monitoring in 2020. Results: As a result, 1,827,536 cases were estimated for 11,052 workplaces in one year. This is much higher than the 5,116 cases of 3818 workplaces of the existing work environment monitoring results. It is confirmed that the exposure limit was exceeded in 10.6~24.0% of the entire period and 70.2~84.1% of the peak period of the heat wave. It is very high compared to 0.9% of the existing work environment monitoring result. Conclusions: It is necessary to improve the system of monitoring and statistics related to extreme heat. Additional considerations are needed regarding WBGT estimation methods, meteorological data, and evaluation time. Various follow-up risk assessment studies for other industries and time series need to be continued.

• Ocean Systems Engineering
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• v.6 no.2
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• pp.143-159
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• 2016

Cargo, such as a Tension Leg Platform (TLP), Semi-submersible platform (Semi), Spar or a circular Floating Production Storage and Offloading (FPSO), are frequently dry-transported on a Heavy Lift Vessel (HLV) from the point of construction to the point of installation. The voyage can span months and the overhanging portions of the hull can be subject to frequent wave slamming events in rough weather. Tie-downs or sea-fastening are usually provided to ensure the safety of the cargo during the voyage and to keep the extreme responses of the cargo, primarily for the installed equipment and facilities, within the design limits. The proper design of the tie-down is dependent on the accurate prediction of the wave slamming loads the cargo will experience during the voyage. This is a difficult task and model testing is a widely accepted and adopted method to obtain reliable sea-fastening loads and extreme accelerations. However, it is crucial to realize the difference in the inherent stiffness of the instrument that is used to measure the tri-axial sea fastening loads and the prototype design of the tie-downs. It is practically not possible to scale the tri-axial load measuring instrument stiffness to reflect the real tie-down stiffness during tests. A correlation method is required to systematically and consistently account for the stiffness differences and correct the measured results. Direct application of the measured load tends to be conservative and lead to over-design that can reflect on the overall cost and schedule of the project. The objective here is to employ the established correlation method to provide proper high-frequency responses to topsides and hull design teams. In addition, guidance for optimizing tie-down design to avoid damage to the installed equipment, facilities and structural members can be provided.

• Journal of Applied Reliability
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• v.18 no.1
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• pp.20-32
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• 2018

Purpose: The purpose of this study is to set up an anomaly detection criteria for sensor data coming from a motorcycle. Methods: Five sensor values for accelerator pedal, engine rpm, transmission rpm, gear and speed are obtained every 0.02 second from a motorcycle. Exploratory data analysis is used to find any pattern in the data. Traditional process control methods such as X control chart and time series models are fitted to find any anomaly behavior in the data. Finally unsupervised learning algorithm such as k-means clustering is used to find any anomaly spot in the sensor data. Results: According to exploratory data analysis, the distribution of accelerator pedal sensor values is very much skewed to the left. The motorcycle seemed to have been driven in a city at speed less than 45 kilometers per hour. Traditional process control charts such as X control chart fail due to severe autocorrelation in each sensor data. However, ARIMA model found three abnormal points where they are beyond 2 sigma limits in the control chart. We applied a copula based Markov chain to perform statistical process control for correlated observations. Copula based Markov model found anomaly behavior in the similar places as ARIMA model. In an unsupervised learning algorithm, large sensor values get subdivided into two, three, and four disjoint regions. So extreme sensor values are the ones that need to be tracked down for any sign of anomaly behavior in the sensor values. Conclusion: Exploratory data analysis is useful to find any pattern in the sensor data. Process control chart using ARIMA and Joe's copula based Markov model also give warnings near similar places in the data. Unsupervised learning algorithm shows us that the extreme sensor values are the ones that need to be tracked down for any sign of anomaly behavior.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.11
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• pp.101-108
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• 2019

In this study, Le Corbusier's ideas were investigated from the view point of modern dualism. Le Corbusier, pioneer of modern architecture, insisted a rationalistic architecture for the industrial period, considering a house as 'machine for living'. In the other way, he tried to arouse emotions through architecture, mentioning a house as 'machine for affecting'. In his writings and paintings, he divided the world in the two opposed things (ex: human and nature, reason and sensation, chaos and order, orthogonal and libre curve, man and woman, sun and moon, lightness and darkness, bull and woman, and etc), and tried to combined the these two divided things. In architecture, he amalgamated his white buildings with the green vegetation, which is styled in the harmony of contrast(nature and articial). In urbanism, Le Corbusier did not divide nature only into three material elements for living(sunlight, air, green space), but also pursued poetic and aesthetic nature through buildings under the rays of sun and among the vegetation. Le Corbusier's dualistic ideas are based on Descartes's modern dualism, which divided the world into the material and the spiritual and into the objective and the subjective. Due to this original division, modern dualism contains the limits of extreme subjectification on human signification and of separation from the world and nature. Le Corbusier pursued the combination of the two divided things to overcome the contradiction of dualism, but his ideas and works contain the limits of the modern dualism.

• Structural Engineering and Mechanics
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• v.72 no.5
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• pp.569-583
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• 2019

Tubular steel sections are widespread all over the world because of their strength and aesthetic appearance. Tubular steel members may exhibit local buckling such as elephant foot or overall buckling under extreme compression load. Recently, external bonding of fiber reinforced polymers (FRP) sheets for strengthening these members has been explored through experimental research. This paper presents three-dimensional nonlinear finite element analysis (FEA) to investigate the structural behavior of strengthening tubular steel members with FRP against local and overall buckling phenomena. Out-of-roundness and out-of-straightness imperfections were introduced to the numerical models to simulate the elephant foot and overall buckling, respectively. The nonlinear analysis preferences such as the integration scheme of the shell elements, the algorithm for solution of nonlinear equations, the loading procedure, the bisection limits for the load increments, and the convergence criteria were set, appropriately enough, to successfully track the sophisticated buckling deformations. The agreement between the results of both the presented FEA and the experimental research was evident. The FEA results demonstrated the power of the presented rigorous FEA in monitoring the plastic strain distribution and the buckling phenomena (initiation and propagation). Consequently, the buckling process was interpreted for each mode (elephant foot and overall) into three sequential stages. Furthermore, the influence of FRP layers on the nonlinear analysis preferences and the results was presented.

• Journal of Applied Reliability
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• v.14 no.2
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• pp.97-102
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• 2014

Radar is an object-detection system that uses radio waves to determine the range, altitude, direction, or speed of objects. High power amplifier Module is the most critical part of the high-power radar transmitter systems. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. Research related to radar has been conducted in various fields according to improvement of the communication technology. But only performance-originated technology development has been dashed; study concerning environment duality and safety concerning reliability are still insufficient. In general, radar module is exposed to the outside, on the means of moving or fixed in a certain place. It should be guaranteed sufficient immunity for a variety of environmental stresses that can occur in the outdoor. HALT is a great process used for quickly finding failure mechanisms in a hardware design and product. By applying various kinds and extreme level of stresses, we can find the operating limits of products. In thesis, we conducted HALT test of the high power amplifier modules which used in military and automotive radar. After the test, we analyzed environmental weaknesses of high power amplifier modules using conventional construction data.