• 한국군사과학기술학회지
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• 제19권3호
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• pp.311-318
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• 2016

This paper shows storage life estimation of next IR(infrared) flare material through accelerated degradation tests. Three temperature conditions for the accelerated degradation tests are 55, 65 and $75^{\circ}C$. Six performances of IR flare material are burning time, IR peak/continuous Intensity, total energy of near/mid-IR and color ratio, and they were measured after the tests. Storage life of the IR flare material was estimated through both analyzing the degradation data of those performances and applying distribution-based degradation models to the data. Over 30 years of storage life at $20^{\circ}C$ is estimated in terms of IR peak intensity with reliability 0.99 and confidence level 99 %. Additionally, 10 years of storage period at $21^{\circ}C$ would be equivalent to 68 days of accelerated test at $65^{\circ}C$ from the activation energy in Arrhenius model.

• 천문학회지
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• 제28권1호
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• pp.77-87
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• 1995

An attempt has been made to analyze time series of $H_\alpha,\;H_\beta,\;and\; H_\gamma$ line profiles taken from a 3B/X6.1 flare which occurred on Oct. 27, 1991 in an active region, NOAA 6891. A total of 22 sets of $H_\alpha,\;H_\beta,\;and\; H_\gamma$ taken with a low and non-uniform time resolution of 10-40 seconds were scanned by PDS with absolute intensity calibration to derive the physical characteristics of the material in the flare chromosphere. Our . results are as follows: (1) The lower Balmer lines observed during the flare activity are broadened by Stark effect. (2) At the peak of the flare activity, the electron temperature of the Balmer line emitting region reaches up to 35000K and its geometrical thickness increases to a scale of $10^4km$, suggesting that high energy particles penetrate deep into the photospheric level.

• 한국군사과학기술학회지
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• 제18권3호
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• pp.267-274
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• 2015

It is necessary to both analyze root-cause of non-conformance of effective illumination time to the specification, and estimate the storage lifetime for 81 mm illuminating projectile stockpiled over 10 years. In this paper, aging mechanism of magnesium flare material due to long-term storage was supposed, and two-stage tests, pre-test and main test based on accelerated degradation tests were performed. Field storage environment of moistureproof was set up, and illumination times in the accelerated degradation tests for temperatures 60 and $70^{\circ}C$ were measured. Then, storage reliability of the projectile was estimated through analyzing the measured data and applying distribution-based degradation models to the data. The $B_{10}$ life by which 10 % of a population of the projectiles will have failed at storage temperature of $25^{\circ}C$ was estimated about 7 years.

• 한국의류학회지
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• 제19권4호
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• pp.628-636
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• 1995

The purpose of this study was to investigate the general distribution trend of drapery according to the material of flare skirt and the body size. 100% polyester and 100% rayon fabrics were chosen to compare the effect on the material type. The results from this study were as follows. (1) Both materials generally had similar trend of drapery (2) The difference of material influenced the shape and the amount of drapery. The amount of drapery in polyester was more than the one in rayon. (3) Rody size didn't significantly influence the shape of grapery. So it is concluded that material type is more important variable than the body size for the drapery.

• Korean Chemical Engineering Research
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• 제52권5호
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• pp.613-619
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• 2014

화학 공장에서 플레어 시스템은 공장의 안전에 지대한 영향을 주는 아주 중요한 요소이다. 만약, 플레어 시스템이 필요보다 작게 설계 된다면, 위급 상황 발생 시 끔찍한 사고를 유발할 수 있다. 반면, 플레어 시스템이 필요보다 크게 설계하게 된다면 공장을 건설하는데 드는 비용의 증가를 피할 수가 없게 된다. 따라서, 산업계에서는 적절한 플레어 시스템의 설계를 위해 정확한 플레어 배출량을 예측하고자 오랫동안 노력해왔다. 미국석유협회에서는 플레어 배출량 계산을 위한 가이드라인을 제시하였고, 많은 설계 회사들은 정상상태 열 및 물질 수지식을 이용한 방법을 개발하여 플레어 배출량을 예측해 왔다. 하지만, 이러한 방법들은 많은 보수적인 가정들 하에 플레어 배출량을 계산하여 필요보다 크게 설계, 막대한 비용을 초래할 수 있다. 본 연구에서는 기존 방법들이 가지는 문제들을 해결하기 위해 공정제어가 포함된 동적 모사를 통해 플레어 배출량을 계산하는 새로운 절차를 제시하였고, 이 절차에 따라 에탄 분리탑의 배출량을 성공적으로 예측함으로써 절차의 효용성을 증명하였다.

• 패션비즈니스
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• 제18권6호
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• pp.38-56
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• 2014

This study compared the flared skirts on 3D simulation and in real to show diverse forms in women's clothing depending on the body's gait and motion. By finding the problems, we suggested the possible methods for utilizing the 3D simulation in the clothing industry. First, the 3D simulation of flared skirts showed similar forms of appearance according to the flare length and volume. However, virtually formed drape shape was even in size and spacing, whereas it was not even in real. Second, according to the results of appearance test on the length and flare volume at $90^{\circ}$ and $180^{\circ}$, both real and 3D simulation skirts were evaluated to have outstanding appearances regardless of the skirt length. However, as the flares volume increased, the skirts with longer length were evaluated to have superior appearances compared to the skirts of shorter length. Third, it showed higher resemblance between the real and virtual simulation, when the skirt had less flare and as the skirt length shortened. However, it showed greater difference between the real and virtual simulation when flare volume and length increased. The length and volume of the skirt and the physical properties of the material are predicted to be different between the real and virtual simulation. However, they usually are similar in forms, so it is believed possible to use for predicting the design's silhouette or the feel when it is worn. This method can be applied on internet shopping malls, which can possibly reduce unnecessary time and expenses.

• Journal of Advanced Research in Ocean Engineering
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• 제4권4호
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• pp.195-203
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• 2018

The wave impact on ships could cause local damage to the ship's hull, which has been a concerning issue during the ship design process. In recent years, local structural damages of ships caused by slamming loads have been reported by accident; therefore, it is necessary to study the local slamming pressure loads and structural response assessment. In the present study, slamming loads around the ship's bow region in the presence of regular wave have been simulated by RANS equations discretized with a cell-centered finite volume method (FVM) in conjunction with the $k-{\Box}$ turbulence model. The dynamic structural response has been calculated using an explicit FE method. By adding the slamming pressure load of each time step to the finite element model, establishing the reasonable boundary conditions, and considering the material strain-rate effects, the dynamic response prediction of the bow flare structure has been achieved. The results and insights of this study will be helpful to design a container ship that is resistant enough to withstand bow flare slamming loads.

• 한국의상디자인학회지
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• 제15권2호
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• pp.77-89
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• 2013

This study investigated the formation of silhouette and hemline shape of knit flare skirts according to the properties of knit material through virtual clothing with a 3D virtual clothing system called i-Designer of Technoa, thus building a database of the property data of knit material to reduce the number of sample making steps repeated and implemented several times in the process of clothes making. The results would help to estimate a silhouette in advance, offer assistance to the development of original knit wear, and explore ways to provide basic data for the development of the knit industry of the nation. The investigator made 12 kinds of experimental clothes to the angles(width of skirt: $90^{\circ}$ and $180^{\circ}$), gauge(7G, 12G, and 15G), and grain directions(wale and bias direction) of experimental clothes for virtual clothing. The dynamic characteristics of knit skirt samples according to each gauge were measured with the KES-FB system. Draper shapes were analyzed with the sectional shape data of hemline based on i-Designer. As for the measurements of the sectional shape of hemline and the formation of silhouette, the number of nodes, the average height of node mountains and valleys, and the hemline width right and left and before and after increased at the angle of $180^{\circ}$ than $90^{\circ}$. As gauges multiplied, the number of nodes, and silhouette angle dropping. When considering grain directions, the number of nodes and silhouette index increased in the wale direction at the angle of $90^{\circ}$ with the number of nodes and silhouette angle increasing in the wale direction at the angle of $180^{\circ}$.

• 한국가스학회지
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• 제25권3호
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• pp.1-8
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• 2021

안전밸브의 배출물질을 처리하는 플레어시스템(Flare system) 중 녹아웃드럼(Knockout drum)은 안전에 있어 핵심설비이나 설치기준이 명확하지 않아 사업장 및 규제기관이 수용 가능한 기준 검토가 필요한 실정이었다. 녹아웃드럼의 국내·외 기준과 선행연구 미비점을 조사하여 대량방출 범위, 중간녹아웃드럼 설치위치, 방출물질 조성 영향에 대하여 우선 연구를 수행하였으며, 연구결과 공정모사(Simulation)조건에서 7,500kg/hr 미만의 소량방출은 기·액 분리가 완전하게 되었고 대량 방출은 중간 녹아웃드럼을 추가하였으나 분리효과가 적게 나타났다. 그러나 응축물질 조성을 증가(몰분율 10%)한 경우 대량방출에서 기·액 분리효과가 상승하는 것으로 조사되었으며, 녹아웃드럼을 공정설비에 인접 설치한 것보다는 스택에 인접 설치한 경우에 기·액 분리효과가 더 크게 분석되었다.

• 대한조선학회논문집
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• 제52권5호
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• pp.418-424
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• 2015

This paper is about the bow structure design of the ship-typed and turret moored FPSO which is subjected to the bow-flare slamming load in harsh North Sea environments. Quad 204 FPSO project involves the redevelopment of the existing Schiehallion FPSO which is damaged by impact wave loads. Normally all offshore systems including FPSO are designed to withstand the 100 year storm I.e. the storm that happens once every hundred years at the location where the system is installed. Several incidents have revealed that impact loading is important issue for moored floating production systems. In this paper, the design impact loads are estimated considering the ship owner’s specification, measured data from model tests, requirements of the classification society rules and results of numerical simulation analyses. The impact pressure by numerical analysis is 1.8 times greater than required value by CSR adopted by IACS. Based on the selected design load, plastic design formulae allowing the local material yielding are applied for the initial scantling of the bow structure. To verify the structural integrity, FE analyses are carried out considering the local area subjected to the impact wave loads. Their results such as structural arrangement, design loads and scantlings are shown and discussed. It is found that plastic design formulae in adopting Initial design phase give sufficiently conservative results in terms of structural strength.