• Proceedings of the IEEK Conference
• /
• 2008.06a
• /
• pp.22-23
• /
• 2008

As technology continues to scale down dramatically into 130nm and below, the impacts of process-induced variations on interconnect as well as device become more severe and significant in 130nm and below design. In order to predict changes of circuit characteristics due to process-induced variations accurately and efficiently, the DFM-Aware design environment has been developed and verified.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.7 no.8
• /
• pp.208-215
• /
• 1999

Using the orthogonal arrays and the occupant analysis software based on the multi-body dynamics , two interactive design algorithms are proposed to improve the initial design of the occupant protection systems. Algorithm 1 sequentially moves the narrow design space within the upper and the lower design limit. Algorithm 2 sequentially reduces the relatively wide design space. Each design algorithm is composed of two levels . The first level is to improve the characteristics of the crash performance considering the noise factors. In order to obtain the robust design, the second level reduces the variations the noise factors. In order to obtain the robust design, the second level reduces the variations due to the tolerance of the design variable. To utilize the algorithm 1, HIC(Head Injury Criterion) , 3 msec criterion value of the chest acceleration and the femur load decreased by 27.4%, 10.4% and 55.8%, respectively. To utilizer the algorithm 2 , the results decreased by 38.0%, 10.5% and 3.0% , respectively.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.32 no.11
• /
• pp.1782-1791
• /
• 2008

The purpose of this study was to find out the hair style image about variations of hair design elements. The method of this study was quasi-experimentation. The twelve color photographs of manikins with various hair style were used as the stimulus. As measuring instrument, a likert scale composed of 35 items of five point adjectives was used. The sample consisted of 157 males and 140 females residing in the Busan area. The range of the age is from 20 to 55. The survey was conducted from August to September in 2007. The data were analyzed by factor analysis, frequency, crosstabs one-way analysis of variance, Duncan's test and t-test used SPSS Packages. The results of this study were as follows: 1. As a result of factor analysis, 8 factors - romantic, natural, elegant, simple, classic, casual, modem and mannish were found out as constructing factors of hairstyle image. 2. As a result of hair style image analysis about variations of hair-length, The short hair style was perceived in modern, mannish, casual, sophisticate, medurm-length style in classic and elegant, long hair style was perceived to be high in romantic and natural. 3. As a result of hair style image analysis about variations of hair design elements, The length of hair style was the most influential element in hair design and secondly important one was the wave of hair style. The color of hair style didn't critical effect on image of hair style.

• Journal of Fashion Business
• /
• v.23 no.1
• /
• pp.145-162
• /
• 2019

This study reviewed photos of women's jackets shown at Milano Collections from 2013 S/S to 2017 F/W to identify the variations and trends in their structural components and design elements with respect to year and season. 576 photos, which consist of 276 S/S jackets and 300 F/W jackets by renowned Italian luxury fashion brands; Giorgio Armani, Gucci, Fendi, Max Mara and Jil Sander, were analyzed. Some of the highlighted findings are as follows; in the structural aspects, the H-line silhouette, below waist to hip line length, natural shoulder line and single button closure were the most frequently appearing components among all the jackets. For the design elements, the largest number of jackets was made of woven fabric in single color, while fur was mostly used in F/W seasons for its warmth, heaviness and bulky appearance. From the results, it was established that variations were made to the jacket components and design elements to the extent that they convey predominant jacket styles with a certain level of practicality and performance. However, the study also found that some of the jackets demonstrated design diversity and innovation by adopting daring styles, bold materials and colors. As the findings of this study identified the variations and trends in women's jacket components in recent years, they can be applied towards developing high end women's jackets to meet the demands and distinctive needs of luxury clothing buyers and distributors.

• Journal of the Korean Society of Safety
• /
• v.27 no.6
• /
• pp.115-121
• /
• 2012

This paper, being the second in a two-part series, presents the robust performance of the proposed design method which can enhance a reliability-based design optimization(RBDO) under the uncertainties of probabilistic models. The robust performances of the solutions obtained by the proposed method, described in the Part 1, are investigated through the parametric studies. A 10-bar truss example is considered, and the uncertain parameters include the number of data observed, and the variations of applied loadings and allowable stresses. The numerical results show that the proposed method can produce a consistent result despite of the large variations in the parameters. Especially, even with the relatively small data set, the analysis results show that the exact probabilistic model can be successfully predicted with optimized design sections. This consistency of estimating appropriate probability model is also observed in the case of the variations of other parameters, which verifies the robustness of the proposed method.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.12 no.2
• /
• pp.41-48
• /
• 2013

Springback is a very typical dimensional discrepancy phenomenon, which occurs usually on the final stamping parts after the tool loading is removed. Variation of springback leads to amplified variations and problems during assembly of the stamped components, in turn, resulting in quality issues. The variations in the properties of the incoming material and process parameters are the main causes of springback variation. In this research, a robust design methodology which combines orthogonal array based experimental design and design space reduction skim to reduce the springback variation for advanced high strength steel parts in sheet metal forming is suggested. The concept of design space reduction is adapted in the experimental design setup to improve the quality of the obtained solution. The effectiveness of the proposed procedures is illustrated through a robust design of springback in metal forming process of a cross member of auto body.

• International Journal of Fluid Machinery and Systems
• /
• v.8 no.2
• /
• pp.102-112
• /
• 2015

In the Nordic grid, a trend observed the recent years is the increase in grid frequency variations, which means the frequency is outside the normal range (49.9-50.1 Hz) more often. Variations in the grid frequency leads to changes in the speed of rotation of all the turbines connected to the grid, since the speed of rotation is closely related to the grid frequency for synchronous generators. When the speed of rotation changes, this implies that the net torque acting on the rotating masses are changed, and the material of the turbine runners must withstand these changes in torque. Frequency variations thus leads to torque oscillations in the turbine, which become dynamical loads that the runner must be able to withstand. Several new Francis runners have recently experienced cracks in the runner blades due to fatigue, obviously due to the runner design not taking into account the actual loads on the runner. In this paper, the torque oscillations and dynamic loads due to the variations in grid frequency are simulated in a 1D MATLAB program, and measured grid frequency is used as input to the simulation program. The maximum increase and decrease in the grid frequency over a 440 seconds interval have been investigated, in addition to an extreme event where the frequency decreased far below the normal range within a few seconds. The dynamic loading originating from grid frequency variations is qualitatively found by a constructed variable $T_{stress}$, and for the simulations presented here the variations in $T_{stress}$ are found to be around 3 % of the mean value, which is a relatively small dynamic load. The important thing to remember is that these dynamic loads come in addition to all other dynamic loads, like rotor-stator interaction and draft tube surges, and should be included in the design process, if not found to be negligible.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.13 no.1
• /
• pp.91-98
• /
• 2011

The purpose of this study is to evaluate the differences of visual image on variations in the shoulder strap and length of the monokini swimsuit. Nine samples were examined: 3 variations of the shoulder strap and 3 variations of the swimsuit length. Data have been obtained from 90 fashion design majors and analyzed using Factor Analysis, Anova, Scheffe's Test and the MCA method. The results of the study are as follows: 1) The visual image, according to changes in the shoulder strap and length of monokini swimsuit, was composed of boldness factor, attention factor and attraction factor. Boldness was the most important factor in the monokini swimsuit. 2) The visual images according to changes in the shoulder strap of the monokini swimsuit are ranked in the order of one shoulder strap, strapless and two shoulder straps. They are shown to be untidy - a trendy image, showy -a characterful image and wanted to dress -an unnatural image. 3) As the swimsuit gets shorter, it has more untidy - trendy image. As the swimsuit gets longer, it looks more tidy and classic. 4) The number of shoulder straps and swimsuit length do not interact with each other in boldness factor, attention factor or attraction factor. However, the number of shoulder straps affects more than swimsuit length in the visual images of the monokini swimsuit.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.17 no.4
• /
• pp.15-27
• /
• 2021

In this study, the effect of design factors in a pump station on the pressure variations which are the main cause of water hammering has been investigated by numerical simulations. As design factors, the flow rate, Young's modulus, diameter, thickness, roughness coefficient of pipeline are considered. The relationships between the pressure variations and the design factors are analyzed. The results show that the pressure variation increases sensitively with the flow rate and Young's modulus, and increases gradually with the thickness and roughness coefficient of pipe, whereas it decreases with the pipe diameter. The wavelength of the pressure wave becomes longer for a smaller Young's modulus, a smaller pipe thickness and a bigger pipe diameter. These relationships are nondimensionalized, and logarithmic curve-fitted functions are proposed by regression analysis. Most effective factors on the nondimensional pressure variation is Young's modulus. Flow rate, roughness coefficient, relative thickness and pipe diameters are the next impact factors.

• Journal of the Society of Naval Architects of Korea
• /
• v.41 no.3
• /
• pp.49-59
• /
• 2004

The paper describes the preliminary ship design method using deterministic approach and probabilistic approach. In deterministic approach, there are computational aspects to applying not only the integration concurrently of principal dimension decisions and hull form variations but also hydrostatic coefficients that applied to optimization iterative process. Therefore, this paper developed that actual design concept at the preliminary ship design more than sequential design which separated in principal dimension decisions and hull form variations. Furthermore, a probabilistic approach at the preliminary ship design is applied to efficiently solve design information uncertainty that compared to deterministic approach.