• Journal of the Korean Society for Precision Engineering
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• v.14 no.12
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• pp.24-29
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• 1997

Recently, Genetic Algorithm(GA), which is a stochastic direct search strategy that mimics the process of genetic evolution, is widely adapted into a search procedure for structural optimization. Contrast to traditional optimal design techniques which use design sensitivity analysis results, GA is very simple in their algorithms and there is no need of continuity of functions(or functionals) any more in GA. So, they can be easily applicable to wide area of design optimization problems. Also, owing to multi-point search procedure, they have higher porbability of convergence to global optimum compared to traditional techniques which take one-point search method. The methods consist of three genetics opera- tions named selection, crossover and mutation. In this study, a method of finding the omtimum size and topology of drilling machine is proposed by using the GA, For rapid converge to optimum, elitist survival model,roulette wheel selection with limited candidates, and multi-point shuffle cross-over method are adapted. And pseudo object function, which is the combined form of object function and penalty function, is used to include constraints into fitness function. GA shows good results of weight reducing effect and convergency in optimal design of drilling machine.

• Geomechanics and Engineering
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• v.34 no.3
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• pp.221-231
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• 2023

Biopolymer stabilization is a sustainable alternative to traditional techniques that cause a lesser negative impact on the environment during production and application. The study aims to minimize the biopolymer dosages by sizing the bio-additives to the nanoscale. This study combines the advantages of bio and nanomaterials in geotechnical engineering applications and attempts to investigate the behaviour of a low viscous biopolymer, nano sodium carboxymethyl cellulose (nCMC), to treat organic soil. Soil is treated with 0.25%, 0.50%, 0.75% and 1.00% of nano-bio additive, and its effect on the plastic behaviour, compaction characteristics, strength, hydraulic conductivity (HC) and compressible nature are investigated. The strength increased by 1.68 times after 90 days of curing at a dosage of 0.5% nCMC through the formation of gel threads connecting the soil particles that stiffened the matrix. The viscosity of 1% nCMC increased exponentially, deterring fluid flow through the voids and reduced the HC by 0.85 times after curing for 90 days. Also, beyond the optimum dosage of 0.50%, the nCMC forms a film around the soil particles that inhibits the inter-particle cohesion causing a reduction in strength. Experimental results show that nCMC can effectively substitute conventional additives to stabilize the soil.

• Journal of the Korea Fashion and Costume Design Association
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• v.25 no.3
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• pp.17-29
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• 2023

This study collected and analyzed reference information on the size labeling method and size of clothing products in 13 online shopping malls for plus size women in their 20s and 30s, and compared the size specification information focusing on jeans. First, in the results of examining the method of clothing size designation, clothing sizes indicated by 1, 2, 3 or physique designation (M, L, XL) differed between shopping malls, and even in the same shopping mall, even if the same size notation was used. Most the clothing sizes were different depending on the type of clothing. For bottoms, it was found that one company used seven size designation methods at the same time, two shopping malls used four size designation methods, and five shopping malls used three size designation methods. In the meantime, in the results of comparing the size specifications of jeans XL (size 88, 32 inches) by product part, for waist and hip circumferences, each of the eight companies showed that the size was smaller than the body size suggested by KS adult women's wear.

• International Journal of Computer Science & Network Security
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• v.24 no.6
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• pp.33-40
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• 2024

Introducing renewable energy sources, such as wind and photovoltaic arrays, in microgrids that supply remote regions with electricity represents a significant leap in electricity generation. Combining photovoltaic panels and diesel engines is one of the most common ways to supply electricity to rural communities. Such hybrid systems can reduce the cost of electricity generation in these remote power systems because they use free energy to balance the power generated by diesel engines. However, the combination of renewable energy sources and diesel engines tends to complicate the sizing and control of the entire system due to the intermittent nature of renewable energy sources. This study sought to investigate this issue in depth. It proposes a robust hybrid controller that can be used to facilitate optimum power sharing between a PV power source and diesel generators based on the dynamics of the available PV energy at any given time. The study also describes a hybrid PV-diesel power plant's essential functional parts that produce electricity for a microgrid using a renewable energy source. Power control needs to be adjusted to reduce the cost of power generation.

• International Journal of Computer Science & Network Security
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• v.24 no.1
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• pp.31-44
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• 2024

People have been using more energy in the last years. Several research studies were conducted to develop sustainable energy sources that can produce clean energy to fulfill our energy requirements. Using renewable energy sources helps to decrease the harm to the environment caused by conventional power plants. Choosing the right location and capacity for DG-RESs can greatly impact the performance of Radial Distribution Systems. It is beneficial to have a good and stable electrical power supply with low energy waste and high effectiveness because it improves the performance and reliability of the system. This research investigates the ideal location and size for solar and wind power systems, which are popular methods for producing clean electricity. A new artificial intelligent algorithm called Nutcracker Optimization Algorithm (NOA) is used to find the best solution in two common electrical systems named IEEE 33 and 69 bus systems to examine the improvement in the efficiency & reliability of power system network by reducing power losses, making voltage deviation smaller, and improving voltage stability. Finally, the NOA method is compared with another method called PSO and developed Hybrid Algorithm (NOA+PSO) to validate the proposed algorithm effectiveness and enhancement of both efficiency and reliability aspects.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.12
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• pp.1441-1452
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• 2003

오늘날 지체장애인의 수는 후천적 원인으로 인하여 점점 증가하는 추세에 있다. 이에 본 연구는 훨체어를 사용하는 하반신마비자 중 성인남성을 중심으로 인체계측을 통해 적합성이 높은 바지를 개발하는데 목적이 있다. 연구 결과는 다음과 같다. 1. 인체계측 결과 하반신마비자들은 정상인과 비교했을 때 허리둘레 및 배둘레에서 유의한 차이를 보여 새로운 치수체계가 필요로 함을 알 수 있었다 또 자세 변화에 따른 둘레항목의 치수 변화와 피부 신축율에 의해 허리선의 변화가 고려되어 평상시의 휠체어에 앉은 자세에서 계측한 항목으로 원형이 설계되어야 할 필요가 있다고 분석되었다. 2. 연구원형은 기성복화 하기 위한 방법으로 먼저 기준치수(98-102)를 선정하고, 원형 각 부위는 절대치로 수치화 시켜서 제시하였다. 뒤밑위길이선은 허리선에서 8cm 늘이고 앞밑위길이선은 허리선에서 6cm 줄여 앉은 자세에서 편안함을 확보할 수 있도록 하였다. 기준치수의 경우 바지길이 107cm, 밑위길이 26cm, 밑위선 28cm, 엉덩이둘레선은 밑위선 위로 8.5cm, 바지부리는 10.5cm이고 외관과 기능성 평가 결과 대부분의 항목에서 우수한 평가를 받았다. 3. 계측 대상자 계측치를 근거로 치수의 출현율을 고려하여 연구 치수체계를 기본 신체부위인 앉은 허리둘레와 앉은 엉덩이둘레의 순으로 적용하여 총 7개의 치수로 설정하였다. 기준치수(98-102)의 연구원형을 마스터 패턴으로 하고 구체적인 원형 부위별 절대치로써 치수 차를 검토하여 연구 그레이딩 룰을 설계하였으며 기준치수 보다 작은 사이즈 88-93과 큰 사이즈 108-111의 적합성을 검증하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.11
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• pp.2199-2214
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• 1994

In order to sufficiently utilize the potential effectiveness of ATM networks, systematic and effective network management and control systems must be employed. In addition to network design, planning, and call routing techniques used in traditional circuit-switched networks. ATM networks can provide logical VP(Virtual Path) reconfiguration capabilities which can adapt to changes in the network environment. With a proper application of the VP reconfiguration technique, ATM networks can reduce the overhead of frequent network redesign and the overhead of call routing processing. However, ATM VP reconfiguration is a very complex and difficult problem which consists of many facets of optimization subproblems such as VP routing. VP sizing, VP terminating point location and VC routing. Most previous research on the ATM logical network reconfiguration problem dealt with the subset of the problem. This paper mathematically formulates the ATM network reconfiguration problem completely considering all subproblems. Since it is very difficult to derive the optimal solution of the formulated problem, we develop a heuristic method based on a Max min bandwidth allocation principle. We show the feasibility of the proposed heuristic method with a simple example.

• Ocean Systems Engineering
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• v.2 no.2
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• pp.99-113
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• 2012

Steel Catenary Risers (SCR) are the simplest and often the most economic solution compared to other riser types such as flexible pipe, riser towers, top tensioned risers, etc. The top of a SCR is connected to the host platform riser porch. The other end of the SCR connects to flowlines from subsea wells. The riser touchdown point (TDP), which is the location along the riser where contact with the sea floor first occurs, exhibits complex behaviors and often results in compression and fatigue related issues. Heave dynamic responses of semisubmersibles in extreme and operating sea states are crucial for feasibility of SCR application. Recent full field measurement results of a deep draft semisubmersible in Hurricane Gustav displayed the considerable discrepancies in heave responses characteristics between the measured and the simulated results. The adequacy and accuracy of the simulated results from recognized commercial software should be examined. This finding raised the awareness of shortcomings of current commercial software and potential risk in mega investment loss and environmental pollutions due to SCR failures. One main objective of this paper is to attempt to assess the importance and necessity of accounting for viscous effects during design and analysis by employing indicator of viscous parameter. Since viscous effects increase with nearly third power of significant wave height, thus newly increased metocean criteria per API in central Gulf of Mexico (GoM) and even more severe environmental conditions in Western Australia (WA) call for fundamental enhancements of the existing analysis tools to ensure reliable and robust design. Furthermore, another aim of this paper is to address the impacts of metocean criteria and design philosophy on semisubmersible hull sizing in WA and GoM.

• The Research Journal of the Costume Culture
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• v.19 no.6
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• pp.1150-1162
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• 2011

Considering the fact that the fit for men's clothes is important for the sizing system modern ready-made pants, an analysis of obese middle-aged men is required at this period of time to determine the appropriate fit for obese men. The following research focused on 635 middle-aged obese men who had a BMI index of at least 25 and a waist circumference from the belly-button level of 34 inches or more. This research deals with the articles of circumference, thickness and other major physical changes that happen during the 30s, 40s, and 50s. According to the analysis of these body measurement articles with specific regard to age, men's height and the height of their waist seemed to decrease as their age increased. This demonstrates that as these men grow older, the waist and stomach slowly curved into a circular and flat body type due to their obesity. In this study, the first factor figure was the height and leg length. The second factor figure was the waist form. The third factor figure was the center thigh circumference. The fourth and fifth factor figures were the hip length and shape. Lastly, the sixth factor figure was the calf circumference. These 6 factor figures construct 80.57% of the volume explanation and showed 3 patterns through a cluster analysis that showed different patterns of obesity forms for waist circumferences in key figure 1, waist and thigh circumferences in key figure 2, and waist and buttocks circumferences. Therefore, it was worthwhile to consider the circumferences of the waist, buttocks and thigh according to the body type category to enhance the drafting of well-fitting pants.

• Journal of the Ergonomics Society of Korea
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• v.27 no.2
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• pp.83-89
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• 2008

Study was developed the metallic plate for fixation in the femur fracture and plates has a firm place in fracture treatment. This plates can be stabilized for fracture fixation as well as biological and dynamical device. The device's designation and sizing has a optimization with bending structural stiffness and strength, known meaning that is reliable regardless of the plate by the short type and long type. The bending strength of the curved metallic long plate has to evaluate a 11,000N and the bending strength of the curved metallic short plate has to evaluate a 6,525N. This see the X-ray image of bending angle made certain of 15$^{\circ}$ at number 2 and same 82.87$^{\circ}$ at number 2, 4, 5, 7, 8, 9, 10 by outside angle, and confirmed 25.26$^{\circ}$ at number 3, 3.68$^{\circ}$ at number 6, 15.64$^{\circ}$ at number 9 by inside angle. This study shows that keep up the metallic plate for fixation in the femur fracture through X-ray Image and the device can be used to support Revision case of Hip Implant and to use a case of Hip screw compression of Hip Neck Fracture. Short plate have a wrapping of femur and long plate have to preserve a pole of femur.