• 한국생산제조학회지
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• 제6권4호
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• pp.130-137
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• 1997

The demand for wire-cut EDM is increasing rapidly in the die and tool making industry. In this study machining characteristics such as machining rate, surface roughness, hand drum form and hardness of machined material are investigated experimentally under the conditions varing pulse on time, pulse off time, peak voltage, wire tension after fixing other conditions in SKD 11 and brass and brass workpiece. It was found that various operating conditions had significant influences on machining characteristics. But the hardness of workpiece was uneffected by operating conditions. Also it was obtained experimentally that brass workpeice had better machinability than SKD 11 one.dition according to the current(Ip) in an electric spark machine : 1) Electrode is utilized Cu and Graphite. 2) Work piece is used the material of carbon steel. The condition of experiment is : 1) Current is varied 0.7(A) to 50(A) and the time of electric discharging to work piece in each time is 30(min) to 60(min). 2) After the upper side of work piece was measured in radius(5$\mu$m) of stylus analyzed the surface roughness to ade the table and graph of Rmax by yielding data. 3) Electro wear ratio is : \circled1Cooper was measured ex-machining and post-machining by the electronic balance. \circled2The ex-machining of graphite measured by it, the post-machining was found the data from volume $\times$specific gravity and analyzed to made its table and graph on ground the data. 4) In order to keep the accuracy of voltage affected to the work piece was equipped with the A.V. R and the memory scope was sticked to the electric spark machine. 5) In order to preserve the precision of current, to get rid of the noise occured by internal resistance of electric spark machine and to force injecting for the discharge fluid , it made the fixed table for a work piece to minimize the work error by means of one's failure during the electric discharging.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2002년도 춘계종합학술대회
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• pp.205-208
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• 2002

국제-국내간의 해저 광케이블을 설치할 때, 해양조사는 사전 정확한 해저지질 및 수심상태를 파악한다. 그리고 안전한 경로를 선정 및 해저 광케이블 매설을 위해서 용이한 위치론 확보하는 작업이다. 또한, PLGR는 광케이블 루트상의 해저 면의 해양 오염 물질(로프, 와이어, 그물)을 사전에 제거하여 광케이블의 해저면 안착을 용이하게 한다. 더불어서 Plough 및 ROV 매설 작업 시 매설작업 성능 향상 및 매설장비의 보호시킬 수 있는 작업이다. 따라서 된 논문은 해저 광케이블 건설 사업에서 해양조사, PLGR 작업을 위해서 선박의 정보를 관리하기 위한 모니터링 시스템에 대해서 논한다. 이를 위해서 GPS, gyrocompass, tension meter 데이터 취득을 위한 시리얼 멀티포트 통신 모듈을 구성, 수신 데이터의 관리 및 운용을 위한 실시간 처리, 그래프 및 인쇄 출력 모듈을 설계 및 구현하였다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1996년도 춘계학술대회 논문집
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• pp.132-136
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• 1996

A Study is a experiment which is figure out to aptimum discharge cutting condition of the surfaceroughness, electric discharging speed and electro wear ratio with Ton Toff and V(voltage) as an input condition according to the current(Ip) in an electric spark machine ; 1)Electrode is utilized Cu(coper) and Graphite. 2)Work piece is used the material of carbon steel. The condition of experiment is; 1)Current is varied 0.7(A) to 50(A). 2)Pulse time(Ton) is varied 3($\mu$s) to 240($\mu$s) and also Toff is varied 7($\mu$s) to 20($\mu$s). 3)The time of electric discharging to work piece in each time is 30(min) to 60(min) 4)After the upper side of work piece was measured in radius (5${\mu}{\textrm}{m}$) of syulus analyzed the surface roughness to made the table and graph of Rmax by yielding data. 5)Electro wear ratio is; \circled1Coper was measured cx-machining and post machining but the electronic baiance. \circled2The ex-machining of graphite measured by it, the post-machining was found the data from volume specific gravity and analyzed to made its table and graph on ground the data 6)In order to keep the accuracy of voltage affected to the work piece was equipped with the A.V.R(Automatic Voltage Regulator). 7)The memory scope was sticked to the electric spark machine. 8)In order to preserve the precision of current, to get rid of the noise occured by internal resistance of electric spark machine and to force injecting for the discharge fluid, it made the fixed table for a work piece to minimize the work error by means of one's failure during the electric discharging According to above results, the surface roughness by the variation of electrodw and current was analyzed to compare KS(Korea Standards) It was decided the optimum condition of electric discharge cutting through analyzing the effect of electric discharge speed and electro wear ratio.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 추계 학술논문 발표대회
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• pp.35-36
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• 2011

Recently, an irregular-shaped super tall building has been increased, aiming toward landmarks of cityscape. However, the complex floor plan derived from an irregular shape requires considerable resources including time, cost, and effort to meet complex structural framework. Based on the motivation, the study proposes a table-form system that is variable slab form appropriate to an irregular shaped floor through improving limitations of an existing table-form system. The variable table-form is expected to reduce construction resources and improve constructability on an irregular floor plan of super tall buildings as well.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.425-428
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• 1997

Effectiveness of corrective machining algorithm is verified experimentally in this paper by performing corrective lapping work to single side and double sides hydrostatic tables. Lapping is applied as machining method. Machining information is calculated from measured motion errors by applying the algorithm, without information on rail profile. It is possible to acquire 0.13pm of linear motion error, 1.40arcsec of angular motion error in the case of single side table, and 0.07pm of linear motion error, 1.42arcsec of angular motion error in the case of double sides table. The experiment is performed by the unskilled person after he experienced a little of preliminary machining. Experimental results show that corrective machining algorithm is very effective, and anyone can improve the accuracy of hydrostatic table by using the algorithm.

• 산업경영시스템학회지
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• 제34권1호
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• pp.97-102
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• 2011

This study was performed to design and develop an ergonomic equipment for strawberry sorting and packing in agricultural working environments. Potential risk of work related musculo-skeletal disorders associated with farm workers performing strawberry sorting and packing was analyzed through interviews, field surveys, work measurement, and working posture evaluation. For the evaluation of working posture, we used REBA, OWAS, and RULA assessment methods to identify multi-factorial risk factors. Based on the result of comprehensive assessment, a new concept of multi-level rotating table for strawberry sorting and packing was proposed to modify awkward working postures and improve the effectiveness of the farm work. Finally, the characteristics and effectiveness of new equipment was discussed in terms of improvements in productivity, safety, and subjective ratings of farm workers. The results of analysis showed that working conditions improved significantly.

• 한국조사연구학회지:조사연구
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• 제12권1호
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• pp.65-88
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• 2011

본 연구는 패널조사에 기초한 다중상태 생명표 모형을 활용하여 우리나라 중고령층의 근로와 은퇴 그리고 사망으로 이어지는 생애과정을 분석하고 있다. 또한 기존의 생명표 분석이 성별 차이만을 고려하였음에 비해 본 연구는 교육수준을 추가적으로 고려하여 생명표를 작성함으로써 근로 및 은퇴 생애과정에서 관측되는 사회계층별 이질성을 추가적으로 고려하고자 하였다. 분석 결과는 근로 및 은퇴 생애과정이 성별 그리고 교육수준별로 매우 이질적인 패턴을 보이고 있음을 보여 주었다. 성별 차이와 관련하여 여성은 남성에 비해 생존기간이 길지만 취업 기대여명이 낮음과 동시에 미취업 기대여명이 높게 나타남으로써 전체 생존 기간에서 미취업 기간이 차지하는 비중이 매우 높은 모습을 보여 주었다. 교육수준별 차이와 관련한 분석 결과는 전반적으로 취업 기대여명에서는 뚜렷한 차이가 관측되지 않는 반면, 미취업 기대여명에서의 격차가 유의미하게 나타남으로써 교육수준별 근로생애 차이는 대체로 미취업 기대여명에서의 차이임을 보여 주었다. 보다 구체적으로, 교육수준이 낮은 개인들은 교육수준이 높은 개인들과 유사한 수준의 취업 기대여명을 갖고 있지만, 미취업 기대여명이 유의미하게 낮음으로 인해 생존 기간의 보다 큰 비중을 노동시장에서 체류하고 있음을 보여 주었다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제13권4호
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• pp.315-323
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• 2013

Vessel Traffic Service (VTS) is being used at ports and in coastal areas of the world for preventing accidents and improving efficiency of the vessels at sea on the basis of "IMO RESOLUTION A.857 (20) on Guidelines for Vessel Traffic Services". Currently, VTS plays an important role in the prevention of maritime accidents, as ships are required to participate in the system. Ships are diversified and traffic situations in ports and coastal areas have become more complicated than before. The role of VTS operator (VTSO) has been enlarged because of these reasons, and VTSO is required to be clearly aware of maritime situations and take decisions in emergency situations. In this paper, we propose a prediction table to improve the work of VTSO through the Cognitive Work Analysis (CWA), which analyzes the VTS work very systematically. The required data were collected through interviews and observations of 14 VTSOs. The prediction tool supports decision-making in terms of a proactive measure for the prevention of maritime accidents.

• 환경위생공학
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• 제18권4호
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• pp.52-63
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• 2003

This paper investigated Taxi drivers physical subjective symptoms and what factors were interviewed caused the symptoms. The 600 owning taxi-drivers in Seoul during four months from August 1st, 2003 to November 30th, 2003. 1. The average age of the owning taxi-drivers was generally quite high 54 years old. It was very high index compared with the Todai Health Index(THI) and Cornell Medical Index(CMI) of health check tables. 2. According to the age in THI health check table, the complains of mental subjective symptom by reason of age was high among 31 to 40 years old. People who belonged that age group showed high fabrication(L), digestion(C) and aggressiveness(F). The results showed the complains of mental subjective symptom. All items except tiredness(I), melancholia(N), and hypersensitivity(P) were commonly reported by people in their sixties. On the other hand, melancholia(N) and hypersensitivity(P), people in their forties were investigated highly. Statistically, the items of heartㆍblood stream(C) and digestion(D) systems were similar between the two ages, but anger(Q) was different. (p<0.05) 3. From the complains of mental and physical subjective symptoms about work satisfaction on the THI health check table, all items except eyeㆍskin trouble(B) showed strong dissatisfaction. From the complains of mental and physical subjective symptoms about work satisfaction on the CMI health check table, the items of respiratory system(B), digestion(D), nervous system(G), miscellaneous(K), inadequancy(M), and anger(Q) showed similar results. Otherwise, heartㆍblood stream(C) showed statistically different. 4. From the complains of mental and physical subjective symptoms on salary satisfaction in the THI health check table, in the case of people receiving around 1 million won, the complains of physical symptoms showed high among all items except for the respiratory(A) and digestion(C) systems. The eyeㆍskin trouble(B) item showed statistical similarity. The complains of mental and physical subjective symptoms according to a salary degree on the CMI health check table was completely different from the above results. In people received around 1~1.5million won, all items except anxiety(O) showed high. The hypersensitivity(P) item showed statistically different.

• 한국산림과학회지
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• 제76권4호
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• pp.348-356
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• 1987

산악지(山岳地) 임도설계(林道設計)의 시간(時間)과 인력(人力)을 절약하는 방법의 일환으로 토량(土量)을 간편하게 산출(産出)하는 방법(方法)을 강구하였다. 이 방법(方法)을 적용하는 이론적(理論的) 배경(背景)으로 0선측량법(線測量法)의 도입(導入)과 2/3 절토노폭개념(切土路幅槪念) 및 절토량(切土量) = 성토량(盛土量) 개념도입(槪念導入)의 타당성을 제시하고 이와같은 원리(原理)들을 산악지림도시공(山岳地林道施工)에 적용한다는 전제하에 삼각함수법을 적용하여 토량환산표(土量換算表)를 표(表) 3과 4와 같이 제작하였다. 표(表) 3은 노폭(路幅)을 0.5m 괄약으로 구분(區分)하여 시공지 경사도별로 절토량(切土量)을 추정(推定)한 것이고, 표(表) 4는 현지(現地)에서 절토폭(切土幅)을 측정하여 절토량(切土量)을 산출(算出)하는데 적용하는 환산계수표(換算係數表)이다. 동표(同表) 등을 적용하면 토량계산(土量計算)을 위한 현지측량(現地測量)과 내업시간(內業時間)은 단축시킬 수 있을 것이다.