• Steel and Composite Structures
• /
• 제45권4호
• /
• pp.579-590
• /
• 2022

One of the biggest problems in structural steel calculation is the design of structures using the lowest possible material weight, making this a slow and costly process. To achieve this objective, several optimization methods have been developed and tested. Nevertheless, a method that performs very efficiently when applied to different problems is not yet available. Based on this assumption, this work proposes a hybrid metaheuristic algorithm for geometric and dimensional optimization of space trusses, called Simulated Squirrel Search Algorithm, which consists of an association of the well-established neighborhood shifting algorithm (Simulated Annealing) with a recently developed promising population algorithm (Squirrel Search Algorithm, or SSA). In this study, two models are tried, being respectively, a classical model from the literature (25-bar space truss) and a roof system composed of space trusses. The structures are subjected to resistance and displacement constraints. A penalty function using Fuzzy Logic (FL) is investigated. Comparative analyses are performed between the Squirrel Search Algorithm (SSSA) and other optimization methods present in the literature. The results obtained indicate that the proposed method can be competitive with other heuristics.

• 전자공학회논문지D
• /
• 제35D권11호
• /
• pp.31-37
• /
• 1998

감쇠기와 위상 변환기로 구성된 진폭/위상 조정 회로는 위상/이득 상호 결합 현상을 일으켜서 최적 동작점을 찾는 데에는 많은 조정 시간이 필요하다. 본 논문에서는 입력신호의 진폭과 위상을 제어하여 출력하는 벡터 감쇠기를 설계하였다. 종전의 벡터 감쇠기는 감쇠기의 위상 변화 특성을 무시하였으나, 본 논문의 벡터 감쇠기는 감쇠기의 위상 변화 특성을 보상하였다. 이 벡터 감쇠기는 0°/180° 위상 변환기, 저위상 변화 감쇠기등으로 이루어지는데, 0°/180° 위상 변환기는 중심주파수 881MHz에서 0°/179.9° 위상 변환 특성을 얻었고, 저위상 변화 감쇠기는 감쇠량이 25dB일 때 위상 변화가 3.6° 이내, 입출력 반사 특성이 -20dB이하를 얻었다. 구현된 벡터 감쇠기는 출력 신호 공간의 직교 좌표 평면을 정확히 표현할 수 있음을 확인하였다.

• 한국실내디자인학회논문집
• /
• 제27권3호
• /
• pp.126-135
• /
• 2018

In the 1960s, rapid urbanization and industrialization created the social atmosphere of individualism in Korea. Individualism has weakened social ties, led to the breakdown of communities, and caused various social problems. So, the paradigm is shifting to a shared society and there are moves to seek ways to solve social problems through community. As part of the initiative, the value and importance of common space in multi-unit dwelling, the typical Korean housing type, is increasing. Thus, the purpose of this study is to identify the trends of domestic research about common space, to assess the current state of domestic academic world and explore the future plans of the common space. The content analysis method was mainly used and statistics were additionally used to analyze 172 preceding research. As a result, research on common spaces showed a steady increase to the current time. And research was being diversified in the field of publishing journals, research contents, research methods and facilities. Until now, most studies have focused on improvement of plan and the quality of common space by identifying the attitude survey, space planning, and the actual situation. Thus many more studies about proper way to operate and manage common space need to be conducted. it is considered that the common space will develop more efficiently. The study is expected to be used as groundwork for the development of the common space and serve as concrete data to show future development directions.

• 한국실내디자인학회논문집
• /
• 제26호
• /
• pp.104-111
• /
• 2001

This study deals with the expressive characteristics of Installation Art and their applicability to environmental design, and as such, aims to specify a artistic methods from the contemporary art. What Installation Art is search of in their works is "the state of relationships" which is "to replace the concept of form with that of structure, and the concept of space with that of the environment" that is, the terms of relations in the overall environment of time and space. Installation Art essentially relies on a multiplicity of forms and attitudes leading to projects which positively make use of "spatial-temporal process" to reaffirm and "problematise" their open-endedness manifest in complex contextuality and shifting temporality. This study presents a new interpretation of spatial-temporal dimension, site-specificity, and intermedia art that we find in Installation Art and tries to combine that new artistic insight a with environmental design to provide a basis for integrated art. This study places a great emphasis on the interdisciplinary approaches to the environment we inhabit, which I hope will contribute to generating a greater number of creative possibilities for environmental design.

• 한국터널지하공간학회 논문집
• /
• 제11권2호
• /
• pp.151-162
• /
• 2009

본 연구에서는 터널 설계구간의 대부분을 차지하는 미시추 구간의 지반 등급 분류를 정량적으로 수행할 수 있는 새로운 접근방법을 제안한다. 본 제안방법은 시추공에서 얻은 직접조사 결과와 시추구간의 전기 비저항 탐사결과를 이용해 인공 신경망을 학습시카고, 학습된 인공 신경망은 미시추 구간의 암반분류 등급을 추론하는데 적용된다. 지반등급 추론은 미시추 구간 영역에서 움직이는 격자형 창(window)의 중심점에서 이루어 지며 창내 귀속된 전기 비저항들은 추론을 위한 참고자료로 시용된다. 인공 신경망 학습은 최선 RPROP(Resilient backpropagation) 인공 신경망 학습 알고리즘과 early-stopping 기법을 이용하여 수행되었다. 본 연구에서는 실제 시추조사가 이루어진 터널현장에 제안기법을 적용하여 미시추 구간의 지반 등급을 추론하였으며, 전통적인 지구통계학적 크리깅(kriging) 기법에 의한 결과와도 상호 비교하였다. 결과적으로 본 연구를 통해 학습된 인공 신경망은 전통 크리깅 방법에 비해 매우 구체적이고 현실적인 예측결과를 제공하였다 또한, 인공 신경망 추론으로부터 얻어진 터널 종단 방향의 RMR과 Q-값의 분포에서는 전기 비저항 탐사로부터 추정된 취약지반 구간의 위치와 잘 일치하였으며, 두 값 상호간의 관계도 선행 연구 결과와 부합하였다.

• 한국실내디자인학회논문집
• /
• 제23권3호
• /
• pp.125-133
• /
• 2014

While shifting from modern society to post-industrial society, social structure is changing from the period which pursues material affluence to that which pursues psychological abundance. Formation of various values along with pursuit of psychological abundance has made the illusion of standardization, massification, and popularization meaningless. Different from functionality oriented approach in the past, today's design requires diversified, multiple and integrated thinking and way in fast-changing social phenomena and stream, and lets human loose from the restriction of time and space thanks to technological development. It appears as new and various attempts along with paradigm shift of the wholle society, however the existing physical and actual things gradually transit to non-physical and non-actual things. Tendency of dematerialization has spread as far as esthetic and environmental genre on the basis of social and philosophical base along with change of consumption culture, and has displayed complex and de-genre aspect. Paradigm shift has expanded the range of communication by changing to user's independent awareness and sensitive concept, among them, light displays various changes of space by taking the role of new medium. Particularly, the light as the media expression beyond the phenomenon of light of traditional concept acts as an essential element to stimulate sensitivity and for experience as an immaterial element which shows this change of space most dramatically. This research aimed at recognizing space in complex dimension, exploring the relation between the light and space through media expression displayed in the realization of immateriality, expanding the meaning of light, and recognizing it as the possibility of creative and future-oriented light space creation which responds to technological development and social change.

• 한국주거학회논문집
• /
• 제21권1호
• /
• pp.53-65
• /
• 2010

Apartment buildings represent the most typical patterns of housing in Korea. The present plans are very different from the previous ones when they appeared for the first time. Although apartment unit plans has changed drastically, they can be classified into several categories. Apartment unit plans reflects the demands of living activities and space dimensions of unit plans have the characteristics of diachronic continuity and carry the values of living culture. Thus this study aims to provide the statistical dimensional data of each room that can be actually used for the design of unit plans by sub-grouping typical unit plans. The statistical data of this study showed that apartment unit plans are shifting from 2bay/3room type to 3bay/3room type in 1990s. It is very peculiar that the typical unit plan of $60\;m^2$ area becomes to resemble that of $85\;m^2$ area. The space arrangement of typical unit plans of both $60\;m^2$ and $85\;m^2$ area is almost identical while only their space dimensions differ slightly. As the mean/mode/median values of space dimensions in a typical unit plan are converging into a range of narrow margin, space dimensions of typical unit plan are contended to be strictly regular. The statistical numeric data of various space dimensions provided in this paper can be applied practically to the design of apartment unit plans for low income class people who are disprivileged in the society.

• 융합신호처리학회논문지
• /
• 제10권2호
• /
• pp.127-131
• /
• 2009

디지털 도파관 모델은 파동 방정식의 일반해를 이용하여 진행파를 표현하고 이 진행파의 파동이동을 지연 라인으로 나타낸다. 일반적인 도파관 모델에서의 단일 지연은 샘플링 시간 간격을 의미하지만, 공간 기준 도파관 모델의 단일 지연은 샘플링된 공간의 거리를 의미한다. 이러한 차이점으로 인해 파동의 이동 거리를 직접적으로 조절할 수 있는 공간기준 도파관 모델이 비브라토 음과 같이 피치가 변하는 음을 합성할 수 있다고 알려져 있다. 본 논문에서는 지연라인의 길이의 비로서 피치가 변하는 음을 합성할 수 있는 시간 기준 디지털 도파관 모델을 제안하고 기존의 공간 기준 도파관 모델과의 성능을 비교하였다.

• 한국해양공학회:학술대회논문집
• /
• 한국해양공학회 2004년도 학술대회지
• /
• pp.204-209
• /
• 2004

This paper describes dynamic manipulability analysis of robotic arms moving in viscous fluid. The Manipulability is a functionality of manipulator system in a given configuration and under the limits of joint ability with respect to the tasks required to bt performed. To investigate the manipulability of underwater robotic arms, a modeling and analysis method are presented. The dynamic equation of motion of underwater manipulator is derived from the Lagrange - Euler equation considering with the hydraulic forces caused by added mass, buoyancy and hydraulic drag. The hydraulic drag term in the equation: is established as analytical form using Denavit - Hartenberg (D-H) link coordination of manipulator. Two analytical approaches based on Manipulability Ellipsoid are presented to visualize the manipulability of robotic arm moving in viscous fluid. The one is scaled ellipsoid which transforms the boundary of joint torque to acceleration boundary of end-effector by normalizing the torque in joint space while the other is shifted ellipsoid which depicts total acceleration boundary of end-effector by shifting the ellipsoid in work space. An analysis example of 2-link manipulator with proposed analysis scheme is presented to validate the method.

• 대한전자공학회논문지SD
• /
• 제41권6호
• /
• pp.43-51
• /
• 2004

본 논문에서는 입력패턴을 triple rail-coding 방식으로 표현한 후 입력의 직렬연결 방법으로 기호치환을 수행하는 광 병렬 변형부호화자리수 가산 시스템을 제안하였다. Triple rail-coding 방식으로 변형부호화자리수 입력을 표현할 때 중복연산 결과가 나오는 입력들은 동일한 패턴으로 전처리하여 기호치환과정의 규칙수를 줄였고, 광 구현시 공간 이동된 입력패턴을 직렬로 연결하여 광을 통과시킴으로써 공간 이동 연산, NOR 연산, 그리고 문턱치 연산과정이 필요 없는 광 가산기를 구현하였다.