• 한국산학기술학회논문지
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• 제15권9호
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• pp.5419-5424
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• 2014

용접 스캘럽은 작은 사분원 또는 반원 형상의 구멍으로서 용접의 작업성 향상을 위한 목적으로 용접선이 교차하는 위치에 시공된다. 선체 블록의 탑재 단계에서는 수많은 T-bar 조인트 용접이 수행되어야하며, 플랜지-웨브의 교차용접이 완료된 후에 육성용접을 통해 모든 스캘럽을 메공하는데 많은 생산시수가 소요된다. 본 연구에서는 특별한 타입의 CBM(ceramic backing material)을 고안하여 T-bar 조인트 용접 시 플랜지-웨브의 교차용접 지점에 시공되던 스캘럽을 삭제함으로써 논-스캘럽 블록 조인트 용접 공법을 개발하였다. 플랜지간 용접 시 플랜지 이면에 접촉한 웨브의 V 용접개선에 삽입이 용이하도록 CBM을 웨지 형상으로 제작하였고 웨브간 용접 개선의 루트갭에 맞추어 불필요한 부분의 절단이 용이하도록 예비 절단면들을 톱니 형상으로 배치하였다. 조선소의 실제 용접조건에 기초한 일련의 실험을 통하여 개발된 논-스캘럽 용접 공법의 유용성을 확인하였다.

• 자원환경지질
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• 제33권1호
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• pp.77-88
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• 2000

The goal of this study is to assess the spatial distribution of natural slopes and cutting slopes under would-be development. For this goal, a quantitative slope stability analysis method using GIS integrated with a computer program was developed. Through field investigations, the discontinuity parameters were collected such as orientation of discontinuity, persistence, spacing, JRC, JCS, and water depth. The distributions were interpolated from the ordinary kriging method in ARC/INFO GIS after variogram analysis. The layers showing all parameters needed for limit equilibrium analysis were constructed. The final layer using GIS works composed of 162,352 polygons, that is, unit slopes. The rock slope stability analysis program was coded by C++ language. This program can calculate geometrical vectors related to rock block failures using input orientation data and direction and dimension of strength to occur failure. Also, this can calculate shear strength of joints through empirical equations and quantitative factors of safety. This methodology was applied to the study area which is located in Jaecheon city and Danyang-gun of the northeastern Keumsu is about 135$km^2$. As a result, the study area was entirely stable but unstable, that is, factor of safety less than 1.0dominantly at the slopes near Keumsil, Daejangri, Keumsungmyun and Sojugol, Mt. Dongsan, Juksongmyun by the natural slope stability analysis. Assuming the cutting slope showing the same direction immediate, and quantitative analysis of factors of safety for a regional area could be conducted through GIS integrated with a computer program of limit equilibrium.

• 수산해양교육연구
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• 제27권1호
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• pp.49-62
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• 2015

As methods reducing damages by jellyfish which enter the coastal areas of Korea, attaching cutting devices to towing nets of otter trawls or pair trawls and/or using a canvas type of cutting nets of small fishing boats have been widely utilized. In order to reduce shut-down damages of power plants in coastal areas due to the mass influx of marine organisms including jellyfish, a possible improvement of the traveling water screen system and various jellyfish influx blocking devices were suggested in this study. The results could be utilized as an important index for reducing damages by jellyfish bloom which cause on a massive scale in summer in Korea.

• 대한조선학회 특별논문집
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• 대한조선학회 2013년도 특별논문집
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• pp.21-29
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• 2013

For the purpose of supporting Curved Blocks, pipe welding is commonly used on Curved panel. Typically, when it comes to attaching supporting pipe on heavy incurvated surface, it makes much loss in the process of design, cutting, welding. This paper gives proper methods to collecting problems and Core conflicts surrounding Support Pipe by using of TOC (Theory Of Constraints). Therefore drawing two solutions, pipe development program and NC generating from pipe development Data for Plate Cutting machine. It describes a process of erasing loss surrounding Support Pipe with "TOC Thinking process" and development of two programs in this paper.

• 한국정밀공학회지
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• 제9권4호
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• pp.22-35
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• 1992

In highly automated machining centers, intelligent sensor fddeback systems are indispensable on order to monitor their operations, to ensure efficient metal removal, and to initate remedial action in the event of accident. In this study, an on-line tool wear detection system for thrning operations is developed, and experimentally evaluated. The system employs multiple sensors and the signals from these sensors are processed using a multichannel autoegressive (AR) series model. The resulting output from the signal processing block is then fed to a previously tranied artificial neural network (multiayered perceptron) to make a final decision on the state of the cutting tool. To learn the necessary input/output mapping for tool wear detection, the weithts and thresholds of the network are adjusted according to the back propagation (BP) method during off-line training. The results of experimental evaluation show that the system works well over a wide range of cutting conditions, and the ability of the system to detect tool wear is improved due to the generalization, fault-tolearant and self-ofganizing properties of the neural network.

• 한국통신학회논문지
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• 제12권3호
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• pp.267-275
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• 1987

회로망내에 존재하는 절점과 가지를 분할하여 몇 개의 부분회로망으로 나누고 분할절점에서의 전압 및 전류관계식으로부터 회로망방정식을 정식화하여 각 부분회로망 별로 독립적으로 처리함으로서 대형회로망을 효율적으로 해석할 수 있도록 하였다. 본 논문에서 제안한 분할회로망에 대한 방정식은 분할하기 전의 단일회로망에 대한 방정식과 비교할 때 절점의 순서만 재 배열한 결과가 되므로, 종래의 단일회로망에 대한 산법을 그대로 분할법에 적용할 수 있다. 또한, 어드미턴스행렬의 블록대각형구조를 이용한 병렬계산 알고리즘을 제시하였다.

• 패션비즈니스
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• 제26권5호
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• pp.135-152
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• 2022

This study aimed to evaluate the user experience of hearable devices for seniors and suggest possible development directions. A literature review, case study, and in-depth interviews were conducted. Based on the literature review, convenience, accessibility, transmissibility, wearability, aesthetics, and interest were determined as the user experience factors of hearable devices. Then, in-depth interviews were conducted with 12 participants aged 60 or older regarding four devices. Participants tried four different types of wireless earphones which were selected based on a case study: open-type, kernel-type, neckband-type, and earring-type. Regarding convenience, the participants preferred to carry small devices and regarding accessibility, participants responded positively for most product types. For transmissibility and wearability, there were differences depending on whether devices were put on correctly, but the participants preferred products that did not wholly block external sounds. For aesthetics, participants preferred small and cutting-edge designs. Interest was noticeable among those who had not used the devices before, and for stability, the neckband-type was the most preferred. Based on the results we suggest designing small cutting-edge designs and button-type assist devices, not blocking the external sound, providing a participation program, simplifying device functions, and establishing a method that can be combined with and stored in clothes and a delivery method that can signal danger.

• 터널과지하공간
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• 제28권6호
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• pp.692-705
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• 2018

발파를 이용한 터널의 굴착 시 수반되는 가장 큰 문제 중 하나는 발파 시 발생하는 지반진동으로 이를 저감시키기 위한 노력의 일환으로 와이어쏘 장비를 이용하여 터널 심발공 주변에 인공 자유면을 형성하고 이를 통해 파쇄도를 향상시키며 동시에 발파 진동을 저감시키는 기술이 개발되어 오고 있다. 본 연구에서는, 실규모 발파 실험 및 3D-DFPA 해석 기법을 통해 인공 자유면의 구조조건에 따른 진동저감 및 발파 효과에 대한 고찰을 수행하였으며, 이에 더불어 인공 자유면 발파에서의 효율적 설계를 위한 경험적 기준을 제안하였다. 분석 결과, 인공 슬롯 자유면은 홉킨슨 효과에 의한 스폴파괴 유발 및 충격진동의 전파경로 차단 등 발파 진동 저감을 야기하는 것으로 판단되었으며, 인공 자유면이 존재하는 경우, 존재하지 않는 경우에 비해 파쇄체적 및 파쇄효율이 모두 증가하는 경향을 보였다. 이는 인공 자유면이 실제 자유면과 동일한 역할을 수행함에 따라 최소저항선의 감소효과를 야기하는 것으로 판단되었으며, 실험 결과를 토대로 발파 공경 및 최소저항선에 대한 발파 파쇄체적의 상관관계를 도출 및 경험적 설계 기준을 제안하였다. 결론적으로, 인공 자유면 발파를 수행 시 발파 공경 대 최소저항선의 비가 약 5에서 8사이의 값을 갖도록 설계하는 것이 가장 이상적인 표준발파 조건에서의 파쇄효과를 기대할 수 있을 것으로 판단되었다.

• 한국초지조사료학회지
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• 제10권3호
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• pp.152-157
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• 1990

To find out the effect of different patterns of nitrogen and potassium distribution on dry matter yield and botanical composition of temperate pastures, a field experiment was conducted with 6 treatments replicated 3 times in a randomized complete block design. It was lasted from September, 1986 to October, 1989 at the Livestock Experiment Station in Suweon. The results obtained are summarized as follows: 1. In early spring, winter hardiness, growth vigour, cold damage and coverage of grasses with 30% dressing of the total amount of N and K20 fertilizer in spring and at the 4th cutting time respectively were better than those of the other treatments. 2. Average dry matter yield for 3 years with heavy dressing in spring and at the 1st cutting time(l1, 187 kg DM/ha) was much more increased by 9% than that of the equally fertilized treatment(l0,24lkg DM/ha). 3. Changes in the botanical composition showed, in general, the same tendency for all treatments except equal N and K20 distribution. However, grassland vegetation with heavy dressing in spring and at the 1st cutting time was changed into relatively good botanical composition with 76.7% grasses, 22.3% legumes and 1.0% herbs at the end of the experiment. 4. By DM yield and botanical composition treatment 3(40-30-15-0-1570) seemed to be an optimal nitrogen and potassium distribution pattern in a temperate pasture.

• 산업공학
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• 제12권3호
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• pp.395-400
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• 1999

Shipbuilding process is composed of hull construction, in which the structural body of a ship is formed, and outfitting, in which all the non-structural parts such as pipes, derricks, engines, machinery, electrical cable, etc. are manufactured, added and assembled. Hull construction can be classified into parts fabrication, block assembly and hull erection. Among them, the parts fabrication is the first manufacturing stage that produces components or zones needed for block assembly and hull construction. More specifically, the parts fabrication is performed through machining processes including marking, cutting, pressing, and/or forming. When material is entering into the parts fabrication stage, it is important for achieving the total efficiency of production to select one of production division, so-called 'bay,' as well as machine tools on which the part is fabricated. In this paper, given production quantities of parts in the fabrication stage, the problem is to optimally select machine tools and production division, such that the total flow-time is minimized as well as the workload among machines is balanced. Specifically, three mathematical models for flow-time minimization, load balance, and simultaneously considering both objectives, and a numerical example are analyzed and presented.