In this study, the additivity factors of compositions to density and glass transition point (Tg) in a xLi2O-(1-x)[(1-y)TeO2-yZnO] (0<x<20, 0<y<20) glass system were analyzed by using mixture design, and the change of ionic conductivity with density and Tg was discussed. As a method for predicting the relation between glass structure and ionic conductivity, density was measured by the Archimedes method. The glass transition point was analyzed to predict the relation between ionic conductivity and the bonding energy between alkali ions and non-bridge oxygen (NBO). The relation equations showing the additivity factor of each composition to the two properties are as follows: Density(g/cm3) = 2.441x1 ＋ 5.559x2 ＋ 4.863x3 Tg(˚C) = 319x1 ＋ 247x2 ＋ 609x3 － 1950x1x3 (x1 : fraction of Li2O, x2 : fraction of TeO2, x3 : fraction of ZnO) The density decreased as Li2O content increased. This was attributed to change of the TeO2 structure. From this structural result, the electric conductivity of the glass samples was predicted following the ionic conduction mechanism. Finally, it is expected that electric conductivity will increase as the activation energy for ion movement decreases.

휴대전화 개발의 기획 단계에서 가장 중요한 고려사항 중 하나는 제품의 전략과 목적에 맞는 적절한 형태인자의 선정이며 현재까지는 주로 직관적이고 정성적인 방법을 사용하고 있다. 본 연구에서는 형태인자 선정의 체계적이고, 합리적 방안을 제시하고자, 감성 형용사를 이용하는 평가 방법론을 제안하였다. 우선 공리설계를 사용하여 개념적 형태인자를 검증하고, 검증된 형태인자의 설계파라미터에 감성형용사를 그룹핑 한다. 그 후 디자이너에게 선정된 형태인자와 그룹화된 감성형용사를 제시하면, 디자이너는 예비 디자인을 수행하고, 그 디자인은 설문조사를 통해 평가 및 분석된다. 이와 같은 일련의 프로세스의 적용결과, 공리설계와 감성공학(감성형용사)의 결합으로 제품의 목적에 적합한 형태인자 디자인을 선정할 수 있었으며 향후 휴대전화 개발에 있어 형태인자 이외의 중요 인자의 선정에도 확대 적용할 수 있는 가능성을 확인할 수 있었다.

A design methodology for parametric design optimization of washing machine door is presented. We develop a motion simulator and a robotic door to simulate the various motion of washing machine doors. The motion of the washing machine door is related to hinge parameters. Springs and dampers are usually used in the hinge of washing machine door for controlling motion of the door. A physical simulator of the door motion is used for finding candidate parameters of the hinge and a robotic door whose motion is controlled algorithmically is used for consumer tests. Through the consumer evaluation on the robotic motion, the optimized parameters are determined. We find the optimal parameters as a function of angle and angular velocity of the door.

For the safe design of steel-concrete composite structure, usable yield strength of steels are limited in most of design standard. However, this limitation sometimes cause the uneconomical design for some kind of members such as slender columns which was affected by elastic buckling load. For the economical design for slender columns, parametric study of RCFT (Rectangular CFT) with high-strength steel is conducted, especially investigating the limitation of yield strength of high-strength steels. Using ABAQUS, finite element analysis program, the finite element model was constructed and calibrated with experimental study for RCFT with high strength steel which have yield strength up to 680MPa. Investigated design parameters are yield strength of steel, compressive strength of concrete, steel thickness and slenderness ratio. The effect of desgn parameters were compared with design standard, KBC-09. From the parametric study with 54 models and previous test specimens, RCFT can be safely design with higher yield strength of steels than currently limited by KBC for large range of slenderness ratio.

An electric motor is the one of the most important parts in robot systems, which mainly drives the wheel of mobile robots or the joint of manipulators. According to the requirement of motor performance, the controller type and parameters vary. For the wheel driving motors, a speed tracking controller is used, while a position tracking controller is required for the joint driving motors. Moreover, if the mechanical parameters are changed or a different motor is used, we might have to tune again the controller parameters. However, for the beginners who are not familiar about the controller design, it is hard to design pertinently. In this paper, we develop a nominal robust controller model for the velocity tracking of wheel driving motors and the position tracking of joint driving motors based on the disturbance observer (DOB) which can reject disturbances, modeling errors, and dynamic parameter variations, and propose the methodology for the determining the least control parameters. The proposed control system enables the beginners to easily construct a controller for the newly designed robot system. The purpose of this paper is not to develop a new controller theory, but to increase the user-friendliness. Finally, simulation and experimental verification have performed through the actual wheel and joint driving motors.

보로 인한 상류부분 유속의 감소로 인해 보의 직상류 부분에 토사물이 퇴적되며 홍수시 수위가 증가하는 원인이 되어 치수 안정성을 저해하고 토사물의 퇴적과 함께 오염 물질도 같이 퇴적되어 수질 악화를 야기할 수 있다. 이러한 보의 단점을 개선하기 위해 본 연구에서 경사형, 슬롯형, 역쐐기 천공형 유사배제 래버린스 보를 제안하였다. 각각의 제안된 보의 수리학적 설계인자 도출을 위해 FLOW-3D를 이용하여 수치실험을 수행하였다. 역쐐기 천공형 래버린스 보의 경우 천공의 영향인자인 단면적, 천공갯수, 직경, 천공높이를 변화시키면서 동일 유량조건에서 수치실험을 수행하였다. 천공의 단면적은 월류고가 기존의 일반형 래버린스 보의 월류 수심보다 보다 10 % 이하로 감소하는 경우에는 수심유지효과가 확보되는 것으로 판단하여 천공의 지름을 결정하였다. 이 결과를 이용하여 슬롯형 유사배제 래버린스 보의 설계인자도 도출하였으며 수심이 10 %이상 감소하도록 설계하여 홍수시 치수안전성을 증가시킬 수 있도록 하였다. 또한, 유사배제효율을 확인하기 위해 보의 상류부분에 particle 형태의 유사를 유입하여 배제효과를 확인하였으며 유입유사 조건은 수리실험에서 주로 사용하는 주문진 표준사조건(d_50 =0.56 mm, σ_g = 1.48)을 적용하였다. 바닥부에서의 난류로 인한 유사배제율 변화를 확인하기 위해 천공의 간격과 높이를 변경하면서 수치실험을 수행하여 유사배제율이 최대가 되는간격과 높이를 도출하였다. 경사형 유사배제 래버린스 보의 경우에도 동일한 흐름 및 유사조건으로 수치모의를 수행하였으며 바닥의 경사를 변화시키면서 경사에 의한 유사배제율 변화를 분석하여 유사배제율이 최대가 되는 경사를 제시하였다. 본 연구에서 도출된 영향인자를 고려하여 유사배제 래버린스 보를 적용하면 기존 보의 단점인 보의 직상류 부분의 유사 퇴적 문제를 일정부분 해소하고 유사연속성을 증가시켜 생태건강성을 향상시킬 수 있을 것으로 판단되며 유사배제 래버린스 보의 활용성을 높일 수 있을 것이라 기대된다.

The result of a small electrostatic precipitator which is in order to decrease indoor air pollution for optimal efficiency was shown as follows. Although the closer distance between the discharge electrode and dust collecting electrode shows the better throughput efficiency by forming strong electrostatic Field, it does not have profound impact in case of optimal dust collecting area. G.P(gas passage) which is the distance from dust collecting electrode to dust collecting electrode is a crucial factor to decide dust collecting efficiency. The narrower distance of G.P shows the better throughput efficiency whereas it decreases when the distance is too narrow since sparks ensue by increasing the capacity of electrostatic charging system 5 mm regards as optimal efficiency in this experiment. Although the higher voltage shows the higher dust collecting efficiency overall, the experiment was not able to keep performing since the sparks which decrease dust collecting efficiency ensue over 40 kV. The efficient and safe voltage state is considered 3.6 kV in this experiment. The most crucial factor for dust collecting efficiency of an electrostatic precipitator which is in order to decrease indoor air pollution is applied voltage. In addition, optimal raw gas flow rate(2.4 m/sec) is more important factor than the excessive increase of dust collecting area.

최근 세계 각지에서는 선박 통항 수역에 해상교량의 건설 운영, 건설 계획 중에 있어 이 해역을 통항하는 선박에게는 위험요소로 작용하여 해양사고를 유발하고 있다. 이 연구는 미국 및 유럽, 일본을 대상으로 해상교량과 관련한 해양사고 인자 분석을 통하여 해상교량 건설 및 기 설치된 해상교량의 안전한 선박통항을 위하여 필요한 환경 요소가 무엇이며 이 환경 요소가 어떻게 설정되어야 하는지에 대하여 분석하였다. 해상교량과 관련한 해양사고 관련 인자는 선박운항자의 실수 이외에 주경간폭, 통항하는 선박크기, 직선거리, 선박교통량 등이 관련하고 있는 것으로 조사되었다. 해양사고 분석을 통한 최소 해상교량 주경간폭은 300m 이상이며, 선박크기가 150m 이상의 선박이 통항하는 해역에서는 주경간폭이 500m 이상이 필요한 것으로 분석되었다. 또한 해상교량 진입 직전 직선거리는 최소한 5L이상이 필요하며 8L(L:선박의 길이) 이상의 확보를 통하여 해양사고를 최소화하여야 할 것이다.

Through this research of the analysis on the frequency flood discharges regarding basin property factors, a linear regression system was introduced, and as a result, the item with the highest correlation with the frequency flood discharges from Nakdong river basin is the basin area, and the second highest is the average width of basin and the river length. The following results were obtained after looking at the multi correlation between the flood discharge and the collected basin property factors using the data from the established river maintenance master plan of the one hundred twenty-five rivers in the Nakdong river basin. The result of analysis on multi- variate correlation between the flood discharges and the most basic data in determining the flood discharges as basin area, river length, basin slope, river slope, average width of basin, shape factor and probability precipitation showed more than 0.9 of correlation in terms of the multi correlation coefficient and more than 0.85 for the determination coefficient. The model which induced a regression system through multi correlation analysis using basin property factors is concluded to be a good reference in estimating the design flood discharge of unmeasured basin.

A demand of marine outfall system has been much increased for the effective disposal of the wastewater due to population and industrial development at the coastal areas. The outfall system discharges primary or secondary treated effluent into the coastline, or at the deep water, or between these two. The discharge is carried out by constructing a pipeline on the sea bed with a diffuser or with a tunnel, risers and appropriate. The effluent, which has a density similar to that of fresh water, rises to the sea surface forming plume or jet, together with entraining the surrounding salt water and becomes very dilute. Thus there have been growing interests about plume behaviour around the outfall system. Plume or jet discharged from single-port or multi-port diffuser might cause certain impacts on coastal environment. Near field mixing characteristics of discharged water field using CORMIX model have been studied for effective outfall design various conditions on ambient current, depth, flow rate, effluent concentration, diffuser specification, port specification etc.. This kind of analysis is necessary to deal with water quality problems caused by the ocean discharge. The analyzed result was applied to the Pusan Jungang effluent outfall system plan.