• 복식문화연구
• /
• 제29권6호
• /
• pp.904-921
• /
• 2021

The aim of this study was to develop a body type suitable for adult men aged from their 20s to their 40s and to present a method of drafting related patterns. To this end, the somatic surface pattern data from previous studies were used. The research method involved drafting torso patterns for each type by setting and distributing the ease to the somatic surface pattern. Appearance evaluation was performed with virtual clothing. Then, the torso pattern for each body type was completed and presented as a draft method. SPSS was used for data analysis in this study. The research results are as follows. Types 1, 2, and 3 were set to 7%, 6%, 5%; 7%, 6%, 4%; and 6.5%, 7%, and 6% for chest, waist, and hip circumference measurements, respectively. The ratio of front to back was 50%:50%, 50%:50%, and 50%:50% of the spare for each body part for Type 1; 70%:30%, 50%:50%, and 60%:40% for Type 2, and 60%:40%, 70%:30%, and 60%:40% for Type 3. A tight-fit torso pattern for each body type suitable for adult males in their 20s to 40s was drafted, which was modified and supplemented through the evaluation of the first and second virtual wear. Considering the practicality of this approach, for generalization of the patterns, the items of the pattern were converted into a drafting method and presented as a draft method.

• Journal of Biosystems Engineering
• /
• 제41권4호
• /
• pp.288-293
• /
• 2016

Purpose: The purpose of this study was to investigate the key factors in designing a three-wheeled two-row soybean reaper (riding type) that is suitable for soybean production, and ensure worker safety by proposing optimal work conditions for the prototype of the designed machine in relation to the slope of the road. Methods: A three-wheeled two-row soybean reaper (riding type) was designed and its prototype was fabricated based on the local soybean-production approach. This approach was considered to be closely related to the prototype-designing of the cutter and the wheel driving system of the reaper. Load distribution on the wheels of the prototype, its minimum turning radius, static lateral overturning angle, tilt angle during driving, and The working and rear overturning (back flip) angle were measured. Based on the gathered information, investigations were conducted regarding optimal work conditions for the prototype. The investigations took into account driving stability and worker safety. Results: The minimum ground clearance of the prototype was 0.5 m. The blade height of the prototype was adjusted such that the cutter was operated in line with the height of the ridges. The load distribution on the prototype's wheels was found to be 1 (front wheel: F): 1.35 (rear-left wheel: RL): 1.43 (rear-right wheel: RR). With the ratio of load distribution between the RL and RR wheels being 1: 1.05, the left-to-right lateral loads were found to be well-balanced. The minimum turning radius of the prototype was 2.0 m. Such a small turning radius was considered to be beneficial for cutting work on small-scale fields. The sliding of the prototype started at $25^{\circ}$, and its lateral overturning started at $39.3^{\circ}$. Further, the critical slope angle for the worker to drive the prototype in the direction of the contour line on an incline was found to be $12.8^{\circ}$, and the safe angle of slope for the cutting was measured to be less than $6^{\circ}$. The critical angle of slope that allowed for work was found to be $10^{\circ}$, at which point the prototype would overturn backward when given impact forces of 1,060 N on its front wheel. Conclusions: It was determined that farmers using the prototype would be able to work safely in most soybean production areas, provided that they complied with safe working conditions during driving and cutting.

• 한국정보통신학회논문지
• /
• 제17권10호
• /
• pp.2245-2251
• /
• 2013

본 논문에서는 사각형 패치가 종단에 장하된 소형 직렬 급전 다이폴 쌍(series-fed dipole pair; SDP) 안테나를 제안하였다. SDP 안테나의 폭을 줄이기 위해 두 다이폴 소자의 두 팔의 종단과 접지면의 양끝에 사각형 패치가 추가되었다. 사각형 패치의 길이와 폭에 따른 입력 반사계수와 같은 안테나 성능의 변화를 분석하였다. 1.7-2.7 GHz 대역에서 동작하는 최적화된 소형 SDP 안테나를 설계하여 FR4 기판 상에 제작하였다. 제작된 안테나의 폭은 기존의 SDP 안테나와 비교하여 14.3% 줄었다. 제작된 SDP 안테나를 측정한 결과, VSWR이 2 이하인 임피던스 대역폭은 48.7%(1.68-2.76 GHz), 이득은 5.6-6.0 dBi으로 기존 SDP 안테나와 유사하며 전후방비는 0.7-7.4 dB 향상되었다.

• 전기전자학회논문지
• /
• 제24권2호
• /
• pp.536-542
• /
• 2020

본 논문에서는 광대역 지향성 방사패턴을 가지는 자연에서 영감을 얻은 새싹 모양 안테나를 제안한다. 모션감지 센서 응용을 위해 넓은 빔폭을 가지는 새싹 모양의 기울어진 방사체를 설계하였다. 확장된 잘려진 접지면을 반사기로 작용하도록 하여 지향성 방사패턴을 가지도록 하였다. 평형 방사체를 급전하기 위하여 우수한 진폭 및 위상 평형도를 가지는 광대역 발룬을 활용하였다. 제안된 안테나는 8.5에서 14.5 GHz의 넓은 주파수 대역폭과 넓은 빔폭을 가졌으며, 방사 효율은 90% 정도이었다. 측정된 이득은 4에서 5dBi이며, 전후방비는 10~20dB이었다. 제안된 안테나는 광대역 넓은 빔폭과 지향성 방사패턴을 요구하는 이미징 센서, 위상 배열 시스템 및 레이더 등에 활용될 수 있음을 보였다.

• Journal of Biosystems Engineering
• /
• 제41권3호
• /
• pp.201-207
• /
• 2016

Purpose: A water-spraying type automatic glochids removal system for cactus (Opuntia humifusa) stem was developed, and its performance was evaluated. The system was developed to reduce intensive human labor in removing glochids from cactus stem skin without inducing damage prior to further processing into value-added products. Methods: The developed system consists of conveyor and water-spraying systems. The conveyor system delivers cactus stems through water-spraying compartments and finally to a collecting box. In order to remove the glochids, rotating nozzles spray water over all areas (i.e., front and back faces and sides) of the cactus skin under controlled water pressure. Operating conditions such as conveyor speed, water pressure, angle of water-spraying nozzles, distance between conveyor belt and rotating nozzles, and angle of cactus flipping slide were adopted from our previous study and applied on the system design and manufacturing. The performance of glochids removal was evaluated by counting the number of glochids on the cactus stem before and after processing on the system. Results: The developed system performed efficiently and effectively under the pre-studied operating conditions except for the angle of cactus flipping slide. The new system had a glochids removal ratio of 94.1% without damaging the cactus skin. Considering the original number (approximately 30-60) of glochids, the remaining number was low (1-4), and most of them were found at the side edge of the cactus stem. This system can remove glochids from 360 cactus stems in 1 hr regardless of cactus size. Conclusions: The performance of the new system in glochids removal without damaging cactus skin is superior to any other existing device (i.e., brush type, rubber-friction type, and agitation type). The system is expected to be applied in cactus (O. humifusa) processing facilities.

• 한국산업융합학회 논문집
• /
• 제24권5호
• /
• pp.597-608
• /
• 2021

The control head components used in small military vessels are designed to be domestically produced, prototypes, structural analysis, and casting methods are designed and cast. The control head assembly consists of a lever, an aluminum outside cover, Middle, front gear cover, back gear cover, and a zinc worm gear. In order to reverse the design of each component, 3D scanning device was used, 3D modeling was performed by CATIA, and prototype productions were carried out by 3D printer. In order to reduce the cost of components, gating system is used by gravity casting method. The SRG ratio of 1:0.9:0.6 was set by applying non-pressurized gating system to aluminum parts, 1:2.2:2.0 and pressurized gating system to zinc parts, and the shapes of sprue, runner and gate were designed. The results of porosity were also confirmed by casting analysis in order to determine whether the appropriate gating system can be designed. The results showed that all parts started solidification after filling completely. ANSYS was used for structural analysis, and the results confirmed that all five components had a safety factor of 15 more. All castings are free of defects in appearance, and CT results show only very small porosity. ZnDC1 zinc alloy worm gear has a tensile strength of 285 MPa and an elongation of 8%. The tensile strength of the four components of A356 aluminum alloy is about 137-162 MPa and the elongation is 4.8-6.5%.

• 한국의류산업학회지
• /
• 제10권5호
• /
• pp.652-659
• /
• 2008

This study was designed to testify the possibility and devise the method to manipulate the 3D body scan data to produce rounded-belt pattern adaptable to hip-type variation of women in their 20's. The results of this research were as follows : Firstly, based on drop-value distribution of hip and waist girth, 151 subjects were classified into three hip-types; Type 1 (15.23%) was 'cylinder type', showing lowest drop-value, Type 2 (69.54%) was 'average type' and Type3 (15.23%) was 'hourglass type' showing highest drop-value. Secondly, using CAD program, design lines for round shape belt were set on the surface of 3D scan data of representative subject of each type. And divided 3D surfaces were flattened onto the plane by the internal tools of CAD program. The measure, 'lifting value of round belt pattern', implying the level of curve ratio of pattern was higher in back than front. This result might be linked to the fact that the hip part is more protruded than the abdomen part. And the measures also showed highest values in Type 3(hourglass type) and lowest in Type 1(cylinder type), meaning that the pattern of Type 3 showed more rounded shape than that of Type 1. This finding implied that round belt for body type having high drop-value should be shaped more curved. Thirdly, difference ratios of outline length and area between 3D curves(body surface) and 2D plane(pattern) were 4.5% and 1.3%, respectively. This result demonstrated and solidified the feasibility of designing digital garment pattern from 3D body scan data.

• 대한전자공학회논문지TC
• /
• 제39권5호
• /
• pp.251-258
• /
• 2002

본 논문에서는 기존외 야기-우다 안테나 배열이론을 마이크로스트립 안테나에 접목시킨 X밴드용 다이폴 급전 평면배열 안테나를 설계하고 제작하였다. 그리고 넓은 대역폭을 갖는 무선통신 시스팀에 쉽게 적용시킬수 있는 다이폴 급전 평면배열 안테나의 설계 절차에 대하여 기술하였다. 또한 FDTD 수치해석법을 이용하여 안테나의 복사특성, 반사손실과 대역폭을 개선시켰으며 제작을 통해 평면형 안테나 해석의 타당성을 입증하였다. 제작한 결과, 10GHz의 중심주파수에서 안테나의 이득은 4.9dBi이고 대역폭은 약 40%, 전후방비는 16dB, E면과 H면의 반 전력 빔폭은 각각 117°와 156°이다. VSWR<2를 기준으로 했을 때, 7.4GHz∼11.88GHZ의 주파수 범위에서 측정결과와 이론적인 결과가 비교적 잘 일치하였다.

• Nuclear Engineering and Technology
• /
• 제37권1호
• /
• pp.91-100
• /
• 2005

Kyung-hee Thorium Fuel (KTF), a heterogeneous thorium-based seed and blanket design concept for pressurized light water reactors, is being studied as an alternative to enhance proliferation resistance and fuel cycle economics of PWRs. The proliferation resistance characteristics of the KTF assembly design were evaluated through parametric studies using neutronic performance indices such as Bare Critical Mass (BCM), Spontaneous Neutron Source rate (SNS), Thermal Generation rate (TG), and Radio-Toxicity. Also, Fissile Economic Index (FEI), a new index for gauging fuel cycle economy, was suggested and applied to optimize the KTF design. A core loaded with optimized KTF assemblies with a seed-to-blanket ratio of 1: 1 was tested at the Korea Next Generation Reactor (KNGR), ARP-1400. Core design characteristics for cycle length, power distribution, and power peaking were evaluated by HELIOS and MASTER code systems for nine reload cycles. The core calculation results show that the KTF assembly design has nearly the same neutronic performance as those of a conventional $UO_2$ fuel assembly. However, the power peaking factor is relatively higher than that of conventional PWRs as the maximum Fq is 2.69 at the M$9^{th}$ equilibrium cycle while the design limit is 2.58. In order to assess the economic potential of a heterogeneous thorium fuel core, the front-end fuel cycle costs as well as the spent fuel disposal costs were compared with those of a reference PWR fueled with $UO_2$. In the case of comprising back-end fuel cycle cost, the fuel cycle cost of APR-1400 with a KTF assembly is 4.99 mills/KWe-yr, which is lower than that (5.23 mills/KWe-yr) of a conventional PWR. Proliferation resistance potential, BCM, SNS, and TG of a heterogeneous thorium-fueled core are much higher than those of the $UO_2$ core. The once-through fuel cycle application of heterogeneous thorium fuel assemblies demonstrated good competitiveness relative to $UO_2$ in terms of economics.

• 한국전자파학회논문지
• /
• 제29권6호
• /
• pp.473-476
• /
• 2018

본 논문에서는 VHF 대역 능동 위상 배열안테나를 구현하기 위한 $2{\times}2$ 부배열 안테나 설계에 대해 연구하였다. 야기-우다 안테나가 복사소자로 적용되었으며, 복사소자의 투사기 굵기 및 도파기 길이 등을 최적화하여 대역폭 확장 및 소형화를 달성하였다. 또한, 그리드 반사기를 사용하여 전후방비를 개선하였고, 무게와 바람저항을 감소시켰다. 제작된 $2{\times}2$ 부배열 안테나는 목표대역($0.98{\sim}1.02f_c$)을 충분히 만족하며, 10.61 dBi의 최대 이득 및 26 dB 이상의 양호한 전후방비 특성을 가진다.