• Journal of Electrical Engineering and Technology
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• v.11 no.5
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• pp.1441-1448
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• 2016

• Journal of the Korean Society for Precision Engineering
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• v.25 no.5
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• pp.60-68
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• 2008

The tool overhang length affects tool deflection and chatter that should be reduced for machined surface quality, productivity and long tool lift. The shortest tool setting algorithm that uses a safe space is proposed and applied with simulation software in NC machining. The safe space in the coordinate fixed in the tool is computed by the virtual machining system that simulates NC machining by stock model, tool model and NC code. The optimal tool assembly that has largest diameter and shortest length is possible using the safe space. This algorithm has been applied over fifty companies for safe and rigid tool setting. The collision accident between holder and stock was reduced from 3 to 0 a year and the productivity was incensed about 15% by using faster feed rate acceptable for shorten tool length.

• Journal of the Korea Society of Computer and Information
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• v.20 no.1
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• pp.127-135
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• 2015

In this paper, we propose and implement an application that recommends safe paths for outdoor leisure activity of women based on Space Syntax theory. Compared to general navigation systems which focuses on the shortest time or the shortest distance, the proposed application makes safe paths the first priority. It generates path recommendation with regard to accessibility of travel time and correlation of regions and considers various risk factors for searching for the safest path. Concludingly, the employed Space Syntax algorithm enables the women users to select their own customized paths.

• Publications of The Korean Astronomical Society
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• v.22 no.4
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• pp.211-217
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• 2007

We have been making dual dome enclosures which are useful to track artificial space objects at SSNT (Space Science and Technology Lab.) Kyung Hee University. We verified the safety of the dome enclosures using basic design and structure analyses before manufacturing them, and then performed an optimization analysis for economic and safe systems. The dome enclosure has a fully-open type structure to smoothly operate a telescope made in the style of altazimuth mount with very fast tracking. It is also designed to be safe against extreme weather conditions. The general structure of the observatory system consists of the dual dome enclosures at the top of a container. For the structural analyses, we consider the following two methods: (1) gravitational sustain analysis - how the structure supporting the dome withstand the weight of the dome, and (2) wind load analysis that considers the effect of the wind velocity at the region where the observatory is located. The result of overall deformation is found to be less than 0.551mm and the result of equivalent stress is found to be 20.293Mpa, indicating that the dual dome system is reasonably designed. This means structurally to be safe.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2010-2015
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• 2003

In this paper, a design and control of the safe arm with passive compliant joints(PCJ) is presented. Each PCJ has a magneto- rheological damper and maximum 6 springs. Compliance analysis in Cartesian space is performed with the compliance ellipsoid; this analysis shows a map between compliance in the joint space and compliance in Cartesian space. Vibration control of the arm using an input shaping technique is also presented; the results of a simulation and an experiment prove that a fast motion of the safe arm without residual vibration can be performed.

• International Journal of Aeronautical and Space Sciences
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• v.6 no.1
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• pp.77-88
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• 2005

KOMPSAT-2 is the second Korean earth observation satellite after KOMPSAT-l: the 1 meter GSD cartographic capability and planning to launch at the end of 2005 by ROKOT launch vehicle. The dedicated AOCS operational modes are designed for KOMPSAT-2 based on KOMPSAT-l experience All of AOCS operational modes requires gyro information. To compensate this drawback, Power Safe Mode is designed and implemented. Successfully AOCS on-board software is developed and extensively verified through a nonlinear simulation process. The simulation results of Power Safe Mode and Science Fine Submode are provided to demonstrate its functionality as well as its performance.

• Journal of the Korean housing association
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• v.8 no.3
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• pp.197-207
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• 1997

This study is about the improvement of housing environment through the research and analysis on how district-level roads are used and what the residents want about housing environment. The results are as follows: 1. As a result of the research on space usage, we could get the conclusion that street furniture occupies much space in the district-level roads, and the main causes of the space usage problems are from cars. 2. Because much space is used for parking, the district-level roads supposed to be the place for the pleasant and safe housing is changing into the main cause of the housing problems. Therefore we should find how to prevent the housing environment from being deteriorated through pridicting the traffic generation of future residential area. 3. Most residents park their cars near their houses in the district-level roads. In order to solve this problem, we have to secure the parking space and guarantee the safe traffic by designing the road space efficiently in spite of the inconvenience.

• Journal of the Korean housing association
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• v.27 no.3
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• pp.39-46
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• 2016

On account of the increasing crime rates annually and the consequent rising anxiety, safety has become an important topic in the aspect of environmental formation to provide decent lives to urban dwellers. As a result, great emphasis has been placed in the importance of Crime Prevention through Environmental Design (CPTED), a design method which utilizes physical environmental design to prevent crime. The definition of CPTED encompasses the technological level of crime prevention as well as comprehensive environmental design which takes into consideration fear or terror in view of human recognition and emotion. However, the current application method of CPTED in Korea is still limited to the technical supplementation of facilities, such as CCTV and streetlight, and fragmental modification like village mural paintings. Moreover, the guideline for CPTED in Korea is only a theoretical adaptation of foreign books and does not offer sufficient studies for a practical design method that will improve the life of city dwellers. The purpose of this study is to examine design methods for safe environment construction in accordance with the changing concept of CPTED by understanding the characteristic of space and analyzing the how the methods of light are expressed. This study aims to provide basic material which will serve as a guideline in creating a safe environment in the future.

• The Journal of Korea Robotics Society
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• v.17 no.1
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• pp.76-85
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• 2022

One of the most fundamental challenges when designing controllers for dynamic systems is the adjustment of controller parameters. Usually the system model is used to get the initial controller, but eventually the controller parameters must be manually adjusted in the real system to achieve the best performance. To avoid this manual tuning step, data-driven methods such as machine learning were used. Recently, reinforcement learning became one alternative of this problem to be considered as an agent learns policies in large state space with trial-and-error Markov Decision Process (MDP) which is widely used in the field of robotics. However, on initial training step, as an agent tries to explore to the new state space with random action and acts directly on the controller parameters in real systems, MDP can lead the system safety-critical system failures. Therefore, the issue of 'safe exploration' became important. In this paper we meet 'safe exploration' condition with Control Barrier Function (CBF) which converts direct constraints on the state space to the implicit constraint of the control inputs. Given an initial low-performance controller, it automatically optimizes the parameters of the control law while ensuring safety by the CBF so that the agent can learn how to predict and control unknown and often stochastic environments. Simulation results on a quadrotor UAV indicate that the proposed method can safely optimize controller parameters quickly and automatically.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.9
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• pp.77-88
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• 2019

This study started with the aim of creating a parenting environment for raising children as a solution to the problem of low fertility. Communal housing is a type of housing where professional childcare environment and lives of family with children can be achieved in community space. It is an environment that supports the development of the child and life of family. However, there is no guidance system for planning such an environment. Therefore, this study aims to develop a pattern language for communal housing of families with children. The research method comes in two steps. First, the documents that provided pattern language and design guidelines about the environment of child and families with children were analyzed. Second, experts specialized in child education, women and family, environmental design were interviewed. As a result of analysis of characteristics of derived pattern language, convenience, safe feeling, comfortability in residential unit, movement, safe feeling, convenience in intermediate space convenience, safe feeling, control in community space were high. The pattern language of this study grafted the items that have proven to be important over a long period of time and the environmental design concepts for families with children in the community space. So it enabled differentiation from existing pattern language or design guidelines.