• The Journal of Advanced Prosthodontics
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• 제5권2호
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• pp.153-160
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• 2013

PURPOSE. This in vitro study intended to investigate the mechanical and thermal characteristics of Valplast, and of polymethyl methacrylate denture base resin in which different esthetic fibers (E-glass, nylon 6 or nylon 6.6) were added. MATERIALS AND METHODS. Five groups were formed: control (PMMA), PMMA-E glass, PMMA-nylon 6, PMMA-nylon 6.6 and Valplast resin. For the transverse strength test the specimens were prepared in accordance with ANSI/ADA specification No.12, and for the impact test ASTM D-256 standard were used. With the intent to evaluate the properties of transverse strength, the three-point bending (n=7) test instrument (Lloyd NK5, Lloyd Instruments Ltd, Fareham Hampshire, UK) was used at 5 mm/min. A Dynatup 9250 HV (Instron, UK) device was employed for the impact strength (n=7). All of the resin samples were tested by using thermo-mechanical analysis (Shimadzu TMA 50, Shimadzu, Japan). The data were analyzed by Kruskal-Wallis and Tukey tests for pairwise comparisons of the groups at the 0.05 level of significance. RESULTS. In all mechanical tests, the highest values were observed in Valplast group (transverse strength: $117.22{\pm}37.80$ MPa, maximum deflection: $27.55{\pm}1.48$ mm, impact strength: $0.76{\pm}0.03$ kN). Upon examining the thermo-mechanical analysis data, it was seen that the E value of the control sample was 8.08 MPa, higher than that of the all other samples. CONCLUSION. Although Valplast denture material has good mechanical strength, its elastic modulus is not high enough to meet the standard of PMMA materials.

• International Journal of Naval Architecture and Ocean Engineering
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• 제6권3호
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• pp.507-528
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• 2014

In the ship and offshore structure design, age-related problems such as corrosion damage, local denting, and fatigue damage are important factors to be considered in building a reliable structure as they have a significant influence on the residual structural capacity. In shipping, corrosion addition methods are widely adopted in structural design to prevent structural capacity degradation. The present study focuses on the historical trend of corrosion addition rules for ship structural design and investigates their effects on the ultimate strength performance such as hull girder and stiffened panel of double hull oil tankers. Three types of rules based on corrosion addition models, namely historic corrosion rules (pre-CSR), Common Structural Rules (CSR), and harmonised Common Structural Rules (CSR-H) are considered and compared with two other corrosion models namely UGS model, suggested by the Union of Greek Shipowners (UGS), and Time-Dependent Corrosion Wastage Model (TDCWM). To identify the general trend in the effects of corrosion damage on the ultimate longitudinal strength performance, the corrosion addition rules are applied to four representative sizes of double hull oil tankers namely Panamax, Aframax, Suezmax, and VLCC. The results are helpful in understanding the trend of corrosion additions for tanker structures.

• 한국농공학회논문집
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• 제53권2호
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• pp.1-8
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• 2011

In this study, In order to evaluate reliable of MODIS GPP, the MODIS GPP and Flux tower measured GPP were compared to evaluate the use of method on 8 days composite MODIS GPP. The 2008 Flux data ($CO_2$ Flux and air temperature) measured in Seolmacheon watershed ($8.48\;km^2$) were used. The Flux tower GPP was estimated as the sum of $CO_2$ Flux and $R_{ec}$ (ecosystem respiration) by Lloyd and Taylor method (1994). The summer Monsoon period from June to August mostly contributed the underestimation of MODIS GPP by cloud contamination on MODIS pixels. The 2008 MODIS GPP and Flux tower GPP of the watershed were $1133.2\;g/m^2/year$ and $1464.3\;g/m^2/year$ respectively and the determination coefficient ($R^2$) after correction of cloud-originated errors was 0.74 (0.63 before correction). Even though effect of Cloud-Originated Errors was eliminated, Solar radiation and Temperature are affected at GPP. Measurement of correct GPP is difficult. But, If errors of MODIS GPP analyze on Cloud Moonsoon Climate in korea and eliminated effect of Cloud-Originated Errors, MODIS GPP will be considered GPP increasing of 9 %. There, Our results indicate that MODIS GPP show reliable and useful data except for summer period in Moonsoon Climate.

• 한국실내디자인학회논문집
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• 제25권2호
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• pp.163-174
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• 2016

The purpose of this study is to reveal the space composition of fireplace and common features of both Prairie and Usonian House found within Wingspread House. This house is the last and largest Prairie house and zoned house built in a Usonian period. However, this house is not an independent work, but rather Wright's evolutionary experiments of fireplace from his early works and his pursuit of Usonian ideal. This paper can be summarized as follows: 1) Living room has been transformed to allow spatial continuity towards exterior view and access and between neighboring rooms by removing doors and inglenook. At the Wingspread house Wright has introduced a freestanding fireplace in a living room with higher and prominent roof structure, therefore the space became a focal point as well as the central space of the entire house. 2) Wingspread and Coonley house have gallery space in common, but they have different settings in the living room composition. Also the living room and gallery space of Wingspread and Usonian houses have prospect and refuge principle by expansion and compression. 3) Wingspread house is a successful combination of Prairie and Usonian style to meet client's requirements in space composition and Wright's technology and economical experiments. This study is intended to reevaluate the significance of this house bridging his two great residential periods.

• 한국실내디자인학회논문집
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• 제5호
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• pp.45-52
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• 1995

Frank Lloyd Wright, a master of the 20th Century Ar-chitecture, contributed tremendously in creating a wholly new form of American architecture called Prairie Style. His idea behind the development of the building structur-al system, organic relationships between inner and outer space, horizontal vertical lines, and idea of extending and expanding interior spaces came from nature. He had completed over 390 projects throughout his life and 90% of those projects were residential design. The most typical characteristic shared by many of his residential design was that each design element, whether it is functional or aesthetical, has close relationship to or-ganic nature, human scale, theoretical floor plants, and maximum emphasis on horizontal lines in respect to na-ture. His concept of "flow of spaces" reformed common the-ory of room next to room in a enclosed space. His sense of "wall" was no longer the side of a box. Careful selec-tion of finishing materials, colors, and natural images en-hance the design as well. F.L. Wright was an artist, designer, and architect who believed the exterior space should have direct relationship to the interior space. His architectural philosophy was not only to design exterior of architecture but also to ful-fill his space through the careful development of interior elements such as furniture, and lighting fixture. Even the patterns for leaded glass windows were designed to have unified appearance from outside to inside of the house. The objective of this study was to analyze floor plans, spatial organizations, and interior design elements of the houses which represent the best of F.L. Wright's design principles and philosophy behind Prairie Style. The meth-od used to collect informations for this study was based on books, articles, journals, and actual site visits. actual site visits.

• 한국잡초학회지
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• 제17권3호
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• pp.269-280
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• 1997

말레이지아 Selangor지역(地域)의 부식질 경지토양(耕地土壤)의 토심(土深) 0-25cm에 매립(埋立)되어있는 잡초종자(雜草種子)들의 종류(種類)와 분포특성(分布特性)을 조사분석(調査分析)하였으며, 이를 지상(地上)에 자라고 있는 잡초식생조사결과(雜草植生調査結果)와 관련시켜 고찰한 결과는 다음과 같이 요약(要約)된다. 1. 경지토양(耕地土壤)에 매립(埋立)되어 있는 잡초종자(雜草種子)는 14과(科)에 속하는 45종(種)의 잡초(雜草)가 식별되었으며, 그중 24종(種)이 광엽잡초(廣葉雜草)이었고, 화본과(禾本科) 12종(種), 사초과(莎草科) 9종(種)으로 지상(地上)에 자라고 있던 19과(科) 31종(種)과는 다소 달랐다. 2. 매립종자수(埋立種子數)는 $8.14{\times}10^7$/ha 토심(土深)25cm 수준이었으며, 초종별(草種別)로 매립종자수(埋立種子數)에 큰 차이(差異)를 보였는데 매립종자수(埋立種子數)에서 광엽잡초(廣葉雜草) 53.2%, 화본과잡초(禾本科雜草)31.2%, 사초과잡초(莎草科雜草) 15.6%로 구성(構成)되어 있었다. 3. 매립종자수(埋立種子數)(종자수(種子數)ha 토심(土深) 25cm)가 많은 10 순위(順位) 초종(草種)은 Cleome rutidesperma($2.347{\times}10^7$), Heteropogon contortus($5.64{\times}10^6$), Paspalum commersonii(4$4.64{\times}10^6$, Amaranthus gracilis ($3.60{\times}10^6$), Bracharia reptans($3.30{\times}10^6$), Fimbrysylis miliacea($2.64{\times}10^6$), Eleusine indica ($2.32{\times}10^6$, Murdannia nudiflora($2.08{\times}10^6$, Ageratum conyzoides($1.92{\times}10^6$), 및 Mimosa pudica($1.92{\times}10^6$)이었다. 4. 매립종자수(埋立種子數)의 토심별(土深別) 분포(分布)는 표토(表土) 0-10cm에 69%, 10-15cm에 17.9%, 15-20cm에 8.6%, 20-25cm에 4.0%로서 표층(表層)에 현저히 많이 분포(分布)하였다. 5. 토중(土中) 매립종자수면(埋立種子數面)에서의 우점종(優點種)은 지면생육중(地面生育中)의 우점도(優點度)와 달라서 매립종자수(埋立種子數)가 제일 많은 C. rutidesperma는 지상(地上)에서 우점도(優點度) 6순위(順位) 이었고 지상(地上)에서 우점도(優點度) 2, 4순위(順位)이었던 M. nudiflora와 A. conyzoides가 매립종자수(埋立種子數)에서 각각 8, 9순위(順位)이었으며 그 밖에는 우점도(優點度) 10순위내(順位內)에서 서로 관련되지 않았다. 6. 매립종자(埋立種子)들의 지리적(地理的) 위치분포(位置分布)에 관하여 분산/평균비(分散)/平均比), Lloyd의 평균군집도(平均群集度), Lloyd의 집중성(集中性) 분석(分析)을 한 결과 평균군집도(平均群集度)가 Cyperus iria 등 5초종(草種)은 1.244수준인데 대하여 Cleome rutidosperma는 9,607.7이었고, 우점도(優點度)는 Aeschynomene indica의 5.1 에서 Bracharia reptans의 188.5까지 초종별(草種別)로 다양한 차이(差異)를 보였다.

• Journal of information and communication convergence engineering
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• 제12권4호
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• pp.215-220
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• 2014

We consider quantization optimized for distributed estimation, where a set of sensors at different sites collect measurements on the parameter of interest, quantize them, and transmit the quantized data to a fusion node, which then estimates the parameter. Here, we propose an iterative quantizer design algorithm with a weighted distance rule that allows us to reduce a system-wide metric such as the estimation error by constructing quantization partitions with their optimal weights. We show that the search for the weights, the most expensive computational step in the algorithm, can be conducted in a sequential manner without deviating from convergence, leading to a significant reduction in design complexity. Our experments demonstrate that the proposed algorithm achieves improved performance over traditional quantizer designs. The benefit of the proposed technique is further illustrated by the experiments providing similar estimation performance with much lower complexity as compared to the recently published novel algorithms.

• 한국해양공학회지
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• 제20권1호
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• pp.16-19
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• 2006

With the fast growth of the shipbuilding industry, the number of lifting lugs used every year has reached onehundred. This paper is aimed at examining the cause of cracking in the hopper top plate, due to block lifting. First of all, we have investigated the fracture surface in the occurrence position of the crack of the hopper top plate, using the scanning electron microscope. In this study, we have evaluated the structural strength for COT super block under present lifting conditions. For this purpose, the equivalent stresses have been calculated by linear elastic analysis, using the finite element program ABAQUS.

• 한국해양공학회지
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• 제23권2호
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• pp.87-91
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• 2009

The welding distortion of a hull structure in the shipbuilding industry is inevitable at each assembly stage. The geometric inaccuracy caused by welding distortion tends to preclude the introduction of automation and mechanization and requires additional man-hours for adjustment work during the following assembly stage. To overcome this problem, a distortion control method should be applied. For this purpose, it is necessary to develop an accurate prediction method that can explicitly account for the influence of various factors on the welding distortion. The validity of this prediction method must also be clarified through experiments. For the purpose of reducing the weld-induced bending deflection, this paper proposes the plastic counter-deforming method (PCDM), which uses line heating as the optimum distortion control method. The validity of this method was substantiated by a number of numerical simulations and actual measurements.

• 한국의류학회지
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• 제21권1호
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• pp.46-57
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• 1997

본 연구의 목적은 두가지 인조섬유 산업, 즉 합성섬유 산업(SITC 266)과 재생섬유 산업(SITC 267)에 있어서, 산업내 무역의 결정요인을 조사하는데 있다. 20개의 주요 인조섬유 수출 국가들을 대상으로 1977, 1982, 1987년의 세 시기에 거힉 자료가 수집되었다. 국제무역 유형을 알아보기 위해 산업내 무역 모델이 사용되었고 종속 변인으로 Grubel-Lloyd지수가 사용되었다. 산업내 무역 을 결정하는 독립변인으로는 국가특성 변인, 국가간 변인, 산업특성 변인의 세 종류가 쓰였다. 국가 특성 변인에는 시장규모, 일인당 소득, 자본-노동 비율 변인들이 사용되었고, 국가간 변인으로는 국가간 거리, 인접국경, 공통언어, 동일 경제블럭 변인들이 사용되었다. 산업특성 변인에는 규모의 경제와 제품차별성 변인들이 쓰였다. 자료의 분석을 위해서는 비선형자승 방법이 이용되었다. 본 연구의 결과, 일인당 소득과 자본-노동의 비율 변인들은 인조섬유의 산업내 무역에 중요하지 않은 것으로 나타났다. 그러나, 시장규모, 국가간 거리, 인접국경, 규모의 경제, 제품차별성 변인들은 모든 시기에 걸켜 산업내 무역에 유의한 영향을 미치는 것으로 나타났다. 또한, 공통언어 사용과 동일 경제블럭 변인들도 대부분의 시기에 인조섬유의 산업내 무역에 유의한 영향을 미치는 것으로 나타났다.