• Pediatric Infection and Vaccine
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• 제31권1호
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• pp.102-112
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• 2024

목적: 우리나라 강원도 내 어린이집, 유치원, 초중고(공교육) 교육시설과 사교육시설을 포함한 교육시설 관련 COVID-19 감염병 집단사례의 역학적 특성과 위험요인을 파악하고자 한다. 방법: 연구기간은 2020년 12월 10일부터 2021년 9월 23일까지 질병관리청 질병보건통합관리시스템에 신고된 강원도 내 코로나19 확진자 5,318명 중 교육시설 관련 집단감염으로 분류된 19개의 교육시설 관련 확진자 407명을 대상으로 조사하였다. 결과: 교육시설 관련 확진자는 19개의 교육시설 총 407명으로 19세 이하는 204명(50.1%) 이었다. 선행 전파자는 가족이 155명(38.1%), 교사125명(30.7%)이었다. 이차감염자가 확진자로부터 노출된 장소는 집이 139명(34.2%)으로 가장 높았다. 총 19개 집단에서 9개 집단의 근원 환자(추정)는 교사로 확인되었다. 교사가 선행 감염원인 경우의 평균 발병률(2.4%)이 학생이 근원 환자(추정)인 집단의 평균 발병률(1.5%)보다 높았다. 또한 교육시설 내 위험도 종합평가 점수가 높은 사교육시설에서 발병률과 2차 발병률이 높았다. 결론: 본 연구에서 교육시설보다는 가정에서의 전파가 더 큰 것이 확인되었고, 교육시설 내 위험도 종합평가점수가 높은 교육시설에서는 교내 발병률이 가정내 발병률보다 높았고, 공교육 시설보다 사교육시설의 위험도 점수가 높은 곳이 많았으며, 교사들이 근원 환자(추정)인 사례가 많았다. 이러한 결과를 근거로 학생들과 더불어 교사들의 방역 수칙 이행에 대한 감시의 강화가 필요하겠다. 또한 지속적인 교육 당국의 모니터링을 통해 감염병 범유행 상황에서 감염으로부터 안전한 환경에서 교육이 이행될 수 있도록 지속적으로 노력해야 할 필요가 있다.

• 대한지리학회지
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• 제42권1호
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• pp.41-62
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• 2007

본 논문은 수도권 집중, 다른 말로 수도권/비수도권 격차의 정도 변화를 제도-정치적 차원의 변인으로부터 해명하고자 하였다. 제도와 그 이면의 사회 내 제 세력 분포의 변화를 지역격차의 변이와 연관짓기 위하여 조절이론의 접근방법을 취하였다. 1980년대는 권위주의 정부 특유의 중앙집권적 권력을 통해, 강력한 조항의 수도권 과밀규제 제도를 갖추고 있었으나, 구체적인 집행이 적절히 이루어지지 않았다. 이는 당시 국가기구의 구조적 선택의 결과로서, 수도권 집중을 완화시키지 못했다. 민주화 과정을 통해 지역이 자신의 발언권을 갖게 되자, 국가기구는 자본의 이해와 지역의 이해를 조정하는 위치에 서게 되었고, 이는 구체적인 수도권 과밀규제 및 지방 성장 정책으로 나타났다. 그리고 1980년대 말에서 외환위기 이전까지 수도권 집중은 뚜렷이 완화되었다. 이러한 변화는 지역의 등장에 힘입은 공간적 조절양식의 변화로 해석되었다. 외환위기는 자본의 역량을 강화시켰고, 국가기구는 자본의 요구에 보다 민감하게 되었다. 자본의 지속적인 수도권 과밀규제 완화 주장을 통해, 수도권 규제는 완화되었고 그 만큼 수도권과 비수도 권간의 격차는 다시 확대되었다.

• 대한교통학회지
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• 제12권1호
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• pp.137-149
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• 1994

The objective of study is to evaluate the effect of speed control hump on traffic operation and accidents. Three sites were investigated for the change of traffic accidents before and after the hump installation. Vehicle speeds approaching the hump were also analyzed. The study revealed that not only the number of traffic accidents but also the accident severity were significantly reduced by the installation of hump. Further, different types of traffic accidents with lower severity were observed after the hump installation. For the effect of speed reduction by hump, it was found that the speeds observed at 15m upstream of hump were in the range of 36~50 percent of approaching speeds which were not affected by (ie, without) the hump. Economic analysis of hump installation showed the benefit-cost ratio of 4.3 and 11.2 at two sites. Further analysis revealed that the benefit by the accident reduction exceeds the cost by speed reduction and installation capital if AADT is below 43,150 vehicles on two lane highways. It is recommended from the study that humps should be considered on two lane highways of high accident locations for excessive speeds to reduce traffic accidents and severity.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2001년도 춘계학술대회 논문집
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• pp.217-220
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• 2001

In the shearing process the burr or rollover must be minimized in order to improve the quality of product. The burr size can be minimized by control of several process parameters. But removal of all burrs are impossible. Most mechanical type deburring methods (vibrating bowls, rotating barrels, shot blasting, for example.) will remove large burrs, other methods use chemical (electro-chemical deburring) or heat (thermal energy deburring). The electro-chemical deburring process removes burrs by the deplating method. Electro-chemical deburring equipment is requires a small capital investment than other methods(mechanical or thermal methods). Electro-chemical deburring method need to many parameters for control such as a time, voltage and concentration of electrolyte. In this paper shows relations of these parameters by experiment.

• 한국IT서비스학회지
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• 제12권3호
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• pp.165-178
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• 2013

The interest in economics and efficiency of IT investment is growing as the amount of overall governmental IT investment steadily increase. Accordingly, there is a strong need to determine whether the expenditure incurs effectively for IT investment and to accurately analyze the economics of IT investment, In this perspective, this study discusses the prior researches on concepts regarding the analysis of IT investment management framework as proposed from academic and professional perspectives in advanced countries' government sectors. Thereafter, an adoption of IT investment management (ITIM) framework has been considered so as to enhance the performance of ICT initiative projects in the public sector. In the suggested IT investment management framework, we suggest economics and efficiency of public IT investment should be improved by integrating ICT project selection and control as well as evaluation stage into single governance framework.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.577-583
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• 2007

In railway business plan, operations require a strategic and sustained level of planned investment to ensure assets are fit for purpose over the whole of their planned life. Therefore it is essential that operator can confidently plan and predict capital investment requirements over a number of years. This research addresses that how the London Underground apply a systematic risk based approach to their health and safety planning and investment decision making. Through this case study, we investigate the elements of management system that includes arrangements for the ongoing identification of hazards, assessment of risks and the implementation necessary control measures. Risk based business planning processes are also addressed.

• 대한산업공학회지
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• 제34권3호
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• pp.296-307
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• 2008

A semiconductor production system has sophisticated manufacturing operations and needs high capital investment for its expensive equipment, which warrants efficient real-time flow control for wafers. In the bay, we consider material handling equipment that can handle multiple carriers of wafers. The dispatching logic first determines the transportation time of each carrier to its destination by each unit of transportation equipment and uses this information to determine the destination machine and target carrier. When there is no available buffer space at the machine tool, the logic allows carriers to stay at the buffer of a machine tool and determine the delay time, which is used to determine the destination of carriers in URL. A simulation study shows this dispatching logic performs better than the procedure currently in use to reduce the mean flow time and average WIP of wafers and increase efficiency of material handling equipment.

• 품질경영학회지
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• 제19권1호
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• pp.170-187
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• 1991

Investments in factory automation do not guarantee productivity enhancement. Much unknown losses may exist in all aspects of production resources such as in material, manpower, machine, etc. Total productivity in korean firms has decreased in recent years. Labor and capital productivity index fall to 0.82 point and 0.73 point, respectively. Investment in FA has Increased rapidly. Tangible fixed assets per capita increased 64% during the past Three years. But, this high-technology oriented systems such as NC, robotics, CAD/CAM, FMS, etc. are often out of keeping with the old production process control, and thus do not result in satisfactory performance. This review paper concerned with these problems and suggests some future directions for production control and development strategy of korean firm's.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.205-210
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• 2004

The PRT(Personal Rapid Transit) system has been being researched and examined to efficiently provide high quality services to passengers against the traffic congestion of the capital region. With concept that PRT differentiated from GRT(Group Rapid Transit), PRT generally is a tracked vehicle system operating with unmanned. The embedded software of PRT Automated Control system generally is comprised of the central software, stations software and vehicle software. The controllers of these software interface to each other using its RF communication antennas. In this paper, each embedded software of the PRT system should be applied to an incremental and systematic test approach technique in the design and implementation phase, because the reliability and safety of the PRT system should be assured

• 한국정밀공학회지
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• 제14권3호
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• pp.156-165
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• 1997

In the practical control systems, the dynamic range of actuatiors is limited(or saturated) when actuators are driven by sufficiently large signals. This gives rise to a nonlinearity as a result of actuator saturation. For example, the upper limit is imposed on productive capability by available factory space and capital equipment. Other examples of those kinds of actuator saturations are a maximum torque of the actua- ting motors and a throttle position in an aircraft speed control A saturating actuator may lead not only to a large overshoot during start-up and shut-down, but also to deterioration of the performance due to the uncertainties. That is, the speed of response is decreased and, possibly, the system output may not follow the lalrge reference inputs. The large-overshoot may be accompanied by rest wind-up(or called by integra- tor wind-up) which comes from controllers with integral action in saturation operation regions. Eventually, as the overshoot increases, the system has a limit cycle or becomes oscillatorily unstable. Due to these cir- cumstances, many studies are focused on the stability and robustness of the nonlinear systems with satu- rating actuator in the time-domain as well as in the frequency-domain.