This study aims to design a new sizing system for hygienic masks to protect against COVID-19-related respiratory disorders. The product sizes were collected from 70 commercially available hygienic masks, and 18 head measurements were obtained from the three-dimensional (3D) scan data of 2,048 men and women aged 20 to 69 years from the 6th Size Korea Survey. The statistical analysis was performed using the IBM Statistical Package for the Social Sciences (SPSS) 28.0 program. The “bitragion-subnasale arc” and “menton-sellion length” were chosen as the key body dimensions for the hygienic mask sizing system. The linear regressions with 18 3D head measurements were analyzed, and it was determined that the key body dimensions were useful for statistically predicting other 3D head measurements related to hygienic masks. A new sizing system was proposed for two types of masks, “masks with a tight fit” and “masks with a loose fit,” taking into account the existing Korean Industrial Standards (KS) and the shortcomings of the sizes of hygienic masks on the market. The sizing system for tight-fitting masks consisted of the key body dimensions, with their sizes indicated by a pair of numbers. The sizing system for loose-fitting masks consisted solely of the bitragion-subnasale arc, with their sizes denoted by letters such as S, M, and L (denoting small, medium, and large, respectively). Future studies should consider this mask sizing system for different age groups, such as children and adolescents.

Due to increasing awareness on the treatment of end-of-use/life products, disassembly has been a fast-growing research area of interest for many researchers over recent decades. This paper introduces a novel lot-sizing problem that has not been studied in the literature, which is the service-parts lot-sizing with disassembly option. The disassembly option implies that the demands of service parts can be fulfilled by newly manufactured parts, but also by disassembled parts. The disassembled parts are the ones recovered after the disassembly of end-of-use/life products. The objective of the considered problem is to maximize the total profit, i.e., the revenue of selling the service parts minus the total cost of the fixed setup, production, disassembly, inventory holding, and disposal over a planning horizon. This paper proves that the single-period version of the considered problem is NP-hard and suggests a heuristic by combining a simulated annealing algorithm and a linear-programming relaxation. Computational experiment results show that the heuristic generates near-optimal solutions within reasonable computation time, which implies that the heuristic is a viable optimization tool for the service parts inventory management. In addition, sensitivity analyses indicate that deciding an appropriate price of disassembled parts and an appropriate collection amount of EOLs are very important for sustainable service parts systems.

This paper describes a novel zero-stress member selecting method for sizing optimization of truss structures. When a sizing optimization method with static constraints is implemented, the member stresses are affected sensitively with changing the variables. However, because some truss members are unaffected by specific loading cases, zero-stress states are experienced by the elements. The zero-stress members could affect the computational cost and time of sizing optimization processes. Feature selection approaches can be then used to eliminate the zero-stress member from the whole variables prior to the process of optimization. Several numerical truss examples are tested using the proposed methods.

This study presents an efficient clothes-sizing system for those experiencing obesity in old age with the aim of revitalizing the clothing industry for older obese people. The study targets 249 obese men aged 60 to 85 who satisfy a Rohrer index score of 1.6 or higher and a BMI (body mass index) of 25 or higher. Elderly obese males showed more obesity in the body based on the waist. In particular, those in their 60s were the most obese, and after reaching their 70s, characteristics of old age in which the stature was reduced and the limbs were tapered were shown. The clothes-sizing system was set to 5cm in stature, 5cm and 3cm in chest girth, 2cm in waist girth (omphalion), and 2cm in hip girth according to the KS standards. Through the two-way distribution of each section, the name of the section with a high distribution was given. Casual tops were selected from eight sizes, ranging from 155 to 170cm in stature and 95 to 105cm in chest girth. Suit top sizes were selected from eight sizes, ranging from 160 to 170cm in stature and 94 to 103cm in chest girth. Bottoms suggested 10 sizes distributed between 90 and 100cm in waist girth (omphalion) and 92 and 98cm in hip girth. According to the KS standards, the detailed size was divided into the basic part and the reference part.

Seismic design of braced frames that simultaneously considers economic issues and structural performance represents a rather complicated engineering problem, and therefore, a systematic and well-established methodology is needed. This study proposes a multi-objective seismic design method for an inverted V-braced frame with suspended zipper struts that uses the non-dominated sorting genetic algorithm-II(NSGA-II). The structural weight and the maximum inter-story drift ratio as the objective functions are simultaneously minimized to optimize the cost and seismic performance of the structure. To investigate which of strength- and performance-based design criteria for braced frames is the critical design condition, the constraint conditions on the two design methods are simultaneously considered (i.e. the constraint conditions based on the strength and plastic deformation of members). The linear static analysis method and the nonlinear static analysis method are adopted to check the strength- and plastic deformation-based design constraints, respectively. The proposed optimal method are applied to three- and six-story steel frame examples, and the solutions improved for the considered objective functions were found.

The purpose of this study is to propose a specialized clothes-sizing system for elderly (aged 60~79) obese women satisfying the following conditions based on the data from the fifth Korean Agency for Technology and Standards (2004): a Rohrer's index of over 1.6, a BMI of over 25, and a WHR of over 0.85. The lower bodies of elderly obese women tends to be shorter and wider than average. Particularly, their torsos from the chest to the waist tend to be more obese than other areas. According to the KS standards, the clothes-sizing system sets up its size intervals as follows: 5cm in stature, 5cm and 3cm in bust, 3cm in waist, and 3cm in hip. Based on the dualistic distribution of each section, the names of the sections indicating high distribution are suggested. For suit tops, 11 sizes are selected as distributed in the 145-155cm stature section and 91-103cm bust section. For casual tops, nine sizes are selected as distributed in the 145-155cm stature section and 90-105cm bust section. For bottoms, 11 sizes are selected as distributed in the 82-97cm waist section and 91-97cm hip section. According to the KS standards, detailed sizes are suggested in the division of basic and reference areas.

Seniors have more economic power, leisure time and better health compared with the past; in addition, there with increased social activity opportunities that allow for active and independent consumption activities based on their economic independence. Therefore, the silver industry for elderly consumers is buoyant in the development of product planning and marketing strategies that target seniors. It is necessary to know the exact characteristics of advanced age along with feet studies that provide basic information on the shape of shoes; however, there are few studies on elderly men's feet. This study develops a shoe sizing system for elderly men based on previous studies which analyzed the aspects of sole shape for individuals aged 60 or over. The distribution on KS G 3405 (2001) was examined and basic items were selected based on a correlation analysis of items related to foot shape. The measurement interval was based on KS and cross analysis was conducted for basic items to select an interval which indicated a frequency of more than 5% by type with a measurement system established by type. The results of the study are as follow. A sizing system was developed with an interval of 5 mm for foot length, an interval of 3 mm for the circumference of the top of the foot and an interval of 6 mm for the circumference of the top of the foot within the same foot length standard to develop a shoe sizing system for elderly men. The respective sizing systems in accordance with type were developed and 12 types of sizing systems were suggested for elderly men to reflect characteristics by type. The differences in sizing system were compared by combining sizing systems by type of sole for elderly men. Type H consists of the greatest number of foot length sections using 7 sections of foot length at 235-265 mm, Type A consists of 6 sections of foot length at 240-265 mm and Type V and D consist of 6 sections of foot length at 235-260 mm. The circumference of the top of the foot has 7 sections from C to F; Type H and A consist of C-EEEE and Type V consists of 6 sections of D-F, and Type D consists of 5 sections of D-EEEE. Type H and A include the sections of small circumference of the top of the foot; however, Type V includes the sections of large circumference of the top of the foot and Type D includes the section of small foot length and a large circumference that indicated differences between type. Type H, subtype 1 (the frontal part of the foot is high and the central part of the foot is low) and 2 (the frontal part of the foot is low and the central part of the foot is high) shows the distribution of size appellation in the sections of C-D where the circumference of the top of the foot is smaller than subtype 3 (the frontal part of the foot is low and the central part of the foot is low) that indicated that the size table is suggested with the reflection of size appellation only for Type H of small width and large height. Appellations are classified in accordance with 3-dimensional type in the section less than 240 mm of foot length. Type V show the same distribution of the appellation (including the section of D-EEE) for all the three types, except for a part of the section of 260 mm. The size appellations of subtypes 2 and 3 are distributed in section F, which indicates the formative characteristics of the foot with a large width or height. Type A has differences in appellation distribution between 3-dimensional types; subtype 2 is distributed in the small circumference section and indicates that Type A has the foot shape with a small width and high height. The distribution of size appellation of subtypes 3 and 1 with the section of large circumference suggests that subtype 3 of Type A (the foot shape with the largest width) has no large foot length and subtype 1 has a large foot length. Type D has differences in appellation among three subtypes, but all of them are included in subtype 1 and suggests that the subtype 1 sizing system can be used. The results indicate that a shoe sizing system for elderly men by foot type could improve the suitability of shoes and provide a wider range of size and satisfaction that helps shoe makers produce shoes of various purpose and function for seniors.

본 논문에서는 Pothead를 지지하는데 사용하는 지그의 고유진동수를 일정 범위로 제한하여 Pothead와 공진을 일으키지 않도록 하는 지그의 최적 설계안을 제시한다. 쿤 터커(Kuhn-Thucker) 조건을 적용한 최적기준법(Optimality criteria method)을 사용하여 위상 최적화를 수행하였고, 이 과정에서 유한요소 크기기 최적 형상에 미치는 영향을 검토하였다. 또한 위상 최적화 결과를 바탕으로 실험 계획법(Design of experiments)과 반응 표면법(Response surface method)을 사용하여 형상 및 치수 최적화를 수행하여 비교용 지그에 비해 전체 질량이 30% 감소되는 결과를 얻었다. 마지막으로 최적화된 지그의 내진 해석을 수행한 Pothead의 응답은 Metal Handbook에서 제시된 내진 응답을 만족하고 있다.

We consider the capacitated lot-sizing and scheduling problem for a paper remanufacturing system that produces several types of corrugated cardboards. The problem is to determine the lot sizes as well as the sequence of lots for the objective of minimizin

The purpose of this study was specifically focused on the lower garment sizing system of adolescent apparel, especially on trousers for adolescent boys. Research Method was performed by using the physical measurements of adolescent boys (14～19 years old, n=1,344) based on the ‘he fifth Korean national physical standard reports’ surveyed by SIZEKOREA. The basic materials for this study are obtained from the observations of physical characteristics and classification of physical figures based on the characteristics from waist down. The results from this study are as follows. 1) according to the analyses of physical changes, most items including height, circumference, length, breadth and depth were increased at the age of 14～18 and gradually reduced at the age of 19. 2) The factors which compose the lower body resulted were appeared that the first factor was vertical factor, the second factor was horizontal factor, the third factor was hip length, and the last factor was buttlock-popliteal length. 3) Formalization of physical figures for adolescent boy's lower body analyzed from factors grouped three types. 4) The basic parts that we used to propose the apparel sizing system distinguished by physical figures were Waist Circumference (Omphalion) (every 3cm regular gap) and Hip Circumference (irregular gap). Physical figures assigned 5 to Type T, and 4 to type M. The reference measurement items were divided into 7 items which are correlated with apparel manufacture.

  본 논문에서는 운송비용과 재고유지비용의 합을 최소화하는 것을 목적으로 유한 계획기간 동안의 수요를 충족시키는 동적 랏사이징 문제를 다룬다. 운송비용을 고려하는 기존의 랏사이징 모형들과는 달리 운송 트럭의 대수에 따라 계단형으로 운송비용이 증가하는 경우를 다루고 있다. 이 문제를 선형정수모형으로 모델링하며 그리디 방식의 휴리스틱을 제안한다. 제안된 휴리스틱의 성능을 평가하기 위해 계산실험을 수행하며, 그 결과 매우 짧은 시간 안에 최적해에 가까운 해를

This lecture introduces new press, adapter and control concepts to size multi-level sintered components. The essential thing here is that the advantages of the multi-plate technology have been applied to the sizing adapter concept. Thus, the new concept meets the demands for a modern P/M manufacture and offers sufficient potential to size any future, complex sintered components such as synchronizer hubs, oil pump wheels and VCT parts with highest precision. Furthermore, it outlines a new flexible concept for the parts transfer, including feeding, orientation and lubrication while responding to the high demands on process stability and short change-over times.