• 제목/요약/키워드: Management Operational Ability

검색결과 65건 처리시간 0.028초

Total reference-free displacements for condition assessment of timber railroad bridges using tilt

  • Ozdagli, Ali I.;Gomez, Jose A.;Moreu, Fernando
    • Smart Structures and Systems
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    • 제20권5호
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    • pp.549-562
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    • 2017
  • The US railroad network carries 40% of the nation's total freight. Railroad bridges are the most critical part of the network infrastructure and, therefore, must be properly maintained for the operational safety. Railroad managers inspect bridges by measuring displacements under train crossing events to assess their structural condition and prioritize bridge management and safety decisions accordingly. The displacement of a railroad bridge under train crossings is one parameter of interest to railroad bridge owners, as it quantifies a bridge's ability to perform safely and addresses its serviceability. Railroad bridges with poor track conditions will have amplified displacements under heavy loads due to impacts between the wheels and rail joints. Under these circumstances, vehicle-track-bridge interactions could cause excessive bridge displacements, and hence, unsafe train crossings. If displacements during train crossings could be measured objectively, owners could repair or replace less safe bridges first. However, data on bridge displacements is difficult to collect in the field as a fixed point of reference is required for measurement. Accelerations can be used to estimate dynamic displacements, but to date, the pseudo-static displacements cannot be measured using reference-free sensors. This study proposes a method to estimate total transverse displacements of a railroad bridge under live train loads using acceleration and tilt data at the top of the exterior pile bent of a standard timber trestle, where train derailment due to excessive lateral movement is the main concern. Researchers used real bridge transverse displacement data under train traffic from varying bridge serviceability levels. This study explores the design of a new bridge deck-pier experimental model that simulates the vibrations of railroad bridges under traffic using a shake table for the input of train crossing data collected from the field into a laboratory model of a standard timber railroad pile bent. Reference-free sensors measured both the inclination angle and accelerations of the pile cap. Various readings are used to estimate the total displacements of the bridge using data filtering. The estimated displacements are then compared to the true responses of the model measured with displacement sensors. An average peak error of 10% and a root mean square error average of 5% resulted, concluding that this method can cost-effectively measure the total displacement of railroad bridges without a fixed reference.

불균형 데이터 처리를 통한 머신러닝 기반 TBM 굴진율 이상탐지 개선 (Enhancing machine learning-based anomaly detection for TBM penetration rate with imbalanced data manipulation)

  • 권기범;황병현;박현태;오주영;최항석
    • 한국터널지하공간학회 논문집
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    • 제26권5호
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    • pp.519-532
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    • 2024
  • TBM (tunnel boring machine) 터널 프로젝트의 리스크 관리 측면에서 굴진율 예측은 중요하며, 이를 위한 머신러닝 기반 TBM 굴진율 예측 연구가 지속적으로 진행되어 왔다. 그러나, 기존 연구의 머신러닝 예측 모델은 정상 굴진율과 이상 굴진율 간의 불균형 데이터를 고려하는 데 한계가 있다. 본 연구에서는 데이터 증강 기법을 통해 불균형 데이터를 처리하여 머신러닝 기반 TBM 굴진율 이상탐지 성능을 개선하였다. 먼저, 상관관계 분석을 통해 유사 변수를 제거하여 6가지 입력특성을 선정하였다. 또한, 하위 10%와 상위 10%의 굴진율을 각각 이상 등급으로, 그 외 범위의 굴진율을 정상 등급으로 굴진율 등급을 구분하였다. 기존 학습 데이터와 SMOTE (synthetic minority oversampling technique)를 통해 증강된 학습 데이터를 각각 XGB (extreme gradient boosting)에 적용한 XGB 모델과 XGB-SMOTE 모델을 구축하였다. 굴진율 등급 예측 성능을 비교한 결과, XGB 모델은 정상 굴진율에 대한 예측 성능은 우수하나 이상 굴진율 예측 성능은 상대적으로 낮게 도출되었다. 반면, XGB-SMOTE 모델은 모든 굴진율 등급에서 일관되게 우수한 예측 성능을 보였다. 이는 SMOTE를 통한 이상 굴진율 데이터의 증강이 이상 굴진율을 유발하는 지반조건과 TBM 운영인자 간의 패턴 학습 수준을 향상시켰기 때문으로 판단된다. 결론적으로, 본 연구는 머신러닝 기반 TBM 굴진율 이상탐지 시 데이터 증강 기법을 활용한 불균형 데이터 처리가 효과적임을 보여준다.

한국의 해양예측, 오늘과 내일 (Korean Ocean Forecasting System: Present and Future)

  • 김영호;최병주;이준수;변도성;강기룡;김영규;조양기
    • 한국해양학회지:바다
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    • 제18권2호
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    • pp.89-103
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    • 2013
  • 경제 발전에 따라 레저, 해운, 수산, 국방, 해난사고 등 해양을 이용하는 활동이 증가하면서 해양예보에 대한 수요가 크게 증가하고 있다. 기상에서 해양의 역할이 새롭게 인식되면서 정확한 기상 및 기후변화를 예측하기 위한 해양 예측의 필요성도 증가하고 있다. 사회적인 요구와 관련 기술의 발전에 힘입어 선진국을 중심으로 해양예측시스템이 수립되어 왔다. 이 연구에서는 세계적으로 해양예측시스템을 발전시키고 확산시킨 국제협력프로그램 GODAE(Global Ocean Data Assimilation Experiment)의 진행과정과 기여를 정리하였다. 그리고 현재 해양예측시스템을 운용 중인 미국, 프랑스, 영국, 이탈리아, 노르웨이, 호주, 일본, 중국이 해양예측시스템을 구축하면서 세웠던 목적과 비전, 역사, 연구 동향을 조사하고 각 나라의 해양예측시스템 현황을 비교하였다. 우리보다 앞서 해양예측시스템을 구축하여 사용하고 있는 나라들이 취한 개발 전략의 특징은 다음과 같이 요약해 볼 수 있다. 첫째, 국가적인 역량을 집중하여 성공적인 현업 해양예측시스템을 구축하였다. 둘째, 국제적인 프로그램을 통해 선진 기술을 공유하고 상호 발전시켰다. 셋째, 각 기관의 역할과 고유 목적에 따라 기여분야를 나눠가졌다. 국내에서도 최근 현업 해양예측시스템에 대한 수요가 증대되고 있다. 기상청, 국립해양조사원, 국립수산과학원, 국방과학연구소의 해양예측시스템 개발에 관한 현재 상황과 향후 장기적 계획을 조사하였다. 국지 해양예측 또는 기후예측 모델을 위한 개방경계 초기장 제공이 가능한 광역의 정확도 높은 해양예측시스템을 구축하기 위해서는 국내의 유관 기관 간 협력 관계가 필수적이다. 이를 위해 관련 기관과 연구자들이 함께 참여하는 컨소시엄 형성이 바람직하다. 컨소시엄을 통해 경쟁력 높은 예측 모델과 시스템을 구축할 수 있으며, 제한된 재원을 효율적으로 활용할 수 있고, 연구 개발 인력이 전문분야에 집중할 수 있으며, 중복 투자를 막고 각 기관은 고유 업무에 역량을 집중할 수 있다. 비록 해양예보에 있어 우리나라가 현 단계로는 국제적인 수준에 뒤쳐져 있지만, 각 유관 기관들이 고유 업무를 정립하고 국가적인 역량을 집중하여 현업 해양예측시스템을 공동 개발하면 곧 추격하여 해양예보 분야를 선도할 수 있을 것이다.

모바일게임 기업의 정성적 평가요인에 관한 연구 (A Study on the Qualitative Evaluation Factors for Mobile Game Company)

  • 최석균;황보윤;이도연
    • 벤처창업연구
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    • 제8권3호
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    • pp.125-146
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    • 2013
  • 최근 모바일 게임이 국내 코스닥 게임 기업들의 기업가치 순위를 좌우하기 시작하면서, 그동안 온라인게임 투자에 주력해왔던 벤처캐피털 등 투자 회사들이 모바일게임 및 모바일게임 기업 투자에 큰 관심을 보이고 있다. 아울러 2012년부터 본격화되기 시작한 엔젤투자자들과 엑셀러레이터들 중에서도 모바일게임 기업 투자가 증가하고 있다. 이러한 모바일 게임투자자들에게 가장 중요한 이슈는 모바일게임 기업 혹은 게임콘텐츠를 어떠한 방법으로 평가할 것인가 하는 것이다. 따라서 본 연구는 모바일게임 기업의 평가에 대한 평가기준과 평가항목을 도출하였다. 연구방법은 게임 수요자 및 공급자의 의견을 수렴하기 위하여 게임업계의 공급을 담당하는 개발사 및 경영자 그룹, 수요를 대변하는 게임전문가 및 투자사 그룹을 포함하는 전문가 20인을 선정하여 델파이 기법(Delphi Technique)에 따라 설문조사를 실시함으로써 모바일게임 기업을 평가할 수 있는 경영능력, 개발력, 게임성, 사업성, 운영능력 등의 5개 평가기준과 경영자의 신뢰도 등 20개의 세부 평가요소를 도출하였다. 또한 델파이 설문을 통하여 도출된 정성적인 요소의 중요도를 분석하기 위하여 AHP(Analytic Hierarchy Process) 이론에 근거하여 모바일게임 기업의 평가를 위한 평가요소의 계층분석도를 작성하였으며, 각 요소에 대한 쌍대비교(Pair-wise Comparison)를 통하여 그 중요도를 분석한 결과, 게임의 핵심적 재미(12.2%), 게임의 몰입도(10.3%), 보안 신뢰성(8.9%), 핵심개발자의 개발능력(7.6%) 등의 순으로 나타났다. 본 연구의 의의는 모바일게임 기업의 M&A나 혹은 프로젝트 투자를 진행함에 있어 모바일게임 기업을 평가하는 현실적 평가요소가 무엇이고 어떤 중요도에 의하여 평가할 것인가에 대한 보다 객관적인 방법론을 제시했다는 점이다.

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병원 간호행정 개선을 위한 연구 (A Study for Improvement of Nursing Service Administration)

  • 박정호
    • 대한간호학회지
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    • 제3권1호
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    • pp.13-40
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    • 1972
  • Much has teed changed in the field of hospital administration in the It wake of the rapid development of sciences, techniques ana systematic hospital management. However, we still have a long way to go in organization, in the quality of hospital employees and hospital equipment and facilities, and in financial support in order to achieve proper hospital management. The above factors greatly effect the ability of hospitals to fulfill their obligation in patient care and nursing services. The purpose of this study is to determine the optimal methods of standardization and quality nursing so as to improve present nursing services through investigations and analyses of various problems concerning nursing administration. This study has been undertaken during the six month period from October 1971 to March 1972. The 41 comprehensive hospitals have been selected iron amongst the 139 in the whole country. These have been categorized according-to the specific purposes of their establishment, such as 7 university hospitals, 18 national or public hospitals, 12 religious hospitals and 4 enterprise ones. The following conclusions have been acquired thus far from information obtained through interviews with nursing directors who are in charge of the nursing administration in each hospital, and further investigations concerning the purposes of establishment, the organization, personnel arrangements, working conditions, practices of service, and budgets of the nursing service department. 1. The nursing administration along with its activities in this country has been uncritical1y adopted from that of the developed countries. It is necessary for us to re-establish a new medical and nursing system which is adequate for our social environments through continuous study and research. 2. The survey shows that the 7 university hospitals were chiefly concerned with education, medical care and research; the 18 national or public hospitals with medical care, public health and charity work; the 2 religious hospitals with medical care, charity and missionary works; and the 4 enterprise hospitals with public health, medical care and charity works. In general, the main purposes of the hospitals were those of charity organizations in the pursuit of medical care, education and public benefits. 3. The survey shows that in general hospital facilities rate 64 per cent and medical care 60 per-cent against a 100 per cent optimum basis in accordance with the medical treatment law and approved criteria for training hospitals. In these respects, university hospitals have achieved the highest standards, followed by religious ones, enterprise ones, and national or public ones in that order. 4. The ages of nursing directors range from 30 to 50. The level of education achieved by most of the directors is that of graduation from a nursing technical high school and a three year nursing junior college; a very few have graduated from college or have taken graduate courses. 5. As for the career tenure of nurses in the hospitals: one-third of the nurses, or 38 per cent, have worked less than one year; those in the category of one year to two represent 24 pet cent. This means that a total of 62 per cent of the career nurses have been practicing their profession for less than two years. Career nurses with over 5 years experience number only 16 per cent: therefore the efficiency of nursing services has been rated very low. 6. As for the standard of education of the nurses: 62 per cent of them have taken a three year course of nursing in junior colleges, and 22 per cent in nursing technical high schools. College graduate nurses come up to only 15 per cent; and those with graduate course only 0.4 per cent. This indicates that most of the nurses are front nursing technical high schools and three year nursing junior colleges. Accordingly, it is advisable that nursing services be divided according to their functions, such as professional, technical nurses and nurse's aides. 7. The survey also shows that the purpose of nursing service administration in the hospitals has been regulated in writing in 74 per cent of the hospitals and not regulated in writing in 26 per cent of the hospitals. The general purposes of nursing are as follows: patient care, assistance in medical care and education. The main purpose of these nursing services is to establish proper operational and personnel management which focus on in-service education. 8. The nursing service departments belong to the medical departments in almost 60 per cent of the hospitals. Even though the nursing service department is formally separated, about 24 per cent of the hospitals regard it as a functional unit in the medical department. Only 5 per cent of the hospitals keep the department as a separate one. To the contrary, approximately 12 per cent of the hospitals have not established a nursing service department at all but surbodinate it to the other department. In this respect, it is required that a new hospital organization be made to acknowledge the independent function of the nursing department. In 76 per cent of the hospitals they have advisory committees under the nursing department, such as a dormitory self·regulating committee, an in-service education committee and a nursing procedure and policy committee. 9. Personnel arrangement and working conditions of nurses 1) The ratio of nurses to patients is as follows: In university hospitals, 1 to 2.9 for hospitalized patients and 1 to 4.0 for out-patients; in religious hospitals, 1 to 2.3 for hospitalized patients and 1 to 5.4 for out-patients. Grouped together this indicates that one nurse covers 2.2 hospitalized patients and 4.3 out-patients on a daily basis. The current medical treatment law stipulates that one nurse should care for 2.5 hospitalized patients or 30.0 out-patients. Therefore the statistics indicate that nursing services are being peformed with an insufficient number of nurses to cover out-patients. The current law concerns the minimum number of nurses and disregards the required number of nurses for operation rooms, recovery rooms, delivery rooms, new-born baby rooms, central supply rooms and emergency rooms. Accordingly, tile medical treatment law has been requested to be amended. 2) The ratio of doctors to nurses: In university hospitals, the ratio is 1 to 1.1; in national of public hospitals, 1 to 0.8; in religious hospitals 1 to 0.5; and in private hospitals 1 to 0.7. The average ratio is 1 to 0.8; generally the ideal ratio is 3 to 1. Since the number of doctors working in hospitals has been recently increasing, the nursing services have consequently teen overloaded, sacrificing the services to the patients. 3) The ratio of nurses to clerical staff is 1 to 0.4. However, the ideal ratio is 5 to 1, that is, 1 to 0.2. This means that clerical personnel far outnumber the nursing staff. 4) The ratio of nurses to nurse's-aides; The average 2.5 to 1 indicates that most of the nursing service are delegated to nurse's-aides owing to the shortage of registered nurses. This is the main cause of the deterioration in the quality of nursing services. It is a real problem in the guest for better nursing services that certain hospitals employ a disproportionate number of nurse's-aides in order to meet financial requirements. 5) As for the working conditions, most of hospitals employ a three-shift day with 8 hours of duty each. However, certain hospitals still use two shifts a day. 6) As for the working environment, most of the hospitals lack welfare and hygienic facilities. 7) The salary basis is the highest in the private university hospitals, with enterprise hospitals next and religious hospitals and national or public ones lowest. 8) Method of employment is made through paper screening, and further that the appointment of nurses is conditional upon the favorable opinion of the nursing directors. 9) The unemployment ratio for one year in 1971 averaged 29 per cent. The reasons for unemployment indicate that the highest is because of marriage up to 40 per cent, and next is because of overseas employment. This high unemployment ratio further causes the deterioration of efficiency in nursing services and supplementary activities. The hospital authorities concerned should take this matter into a jeep consideration in order to reduce unemployment. 10) The importance of in-service education is well recognized and established. 1% has been noted that on the-job nurses. training has been most active, with nursing directors taking charge of the orientation programs of newly employed nurses. However, it is most necessary that a comprehensive study be made of instructors, contents and methods of education with a separate section for in-service education. 10. Nursing services'activities 1) Division of services and job descriptions are urgently required. 81 per rent of the hospitals keep written regulations of services in accordance with nursing service manuals. 19 per cent of the hospitals do not keep written regulations. Most of hospitals delegate to the nursing directors or certain supervisors the power of stipulating service regulations. In 21 per cent of the total hospitals they have policy committees, standardization committees and advisory committees to proceed with the stipulation of regulations. 2) Approximately 81 per cent of the hospitals have service channels in which directors, supervisors, head nurses and staff nurses perform their appropriate services according to the service plans and make up the service reports. In approximately 19 per cent of the hospitals the staff perform their nursing services without utilizing the above channels. 3) In the performance of nursing services, a ward manual is considered the most important one to be utilized in about 32 percent of hospitals. 25 per cent of hospitals indicate they use a kardex; 17 per cent use ward-rounding, and others take advantage of work sheets or coordination with other departments through conferences. 4) In about 78 per cent of hospitals they have records which indicate the status of personnel, and in 22 per cent they have not. 5) It has been advised that morale among nurses may be increased, ensuring more efficient services, by their being able to exchange opinions and views with each other. 6) The satisfactory performance of nursing services rely on the following factors to the degree indicated: approximately 32 per cent to the systematic nursing activities and services; 27 per cent to the head nurses ability for nursing diagnosis; 22 per cent to an effective supervisory system; 16 per cent to the hospital facilities and proper supply, and 3 per cent to effective in·service education. This means that nurses, supervisors, head nurses and directors play the most important roles in the performance of nursing services. 11. About 87 per cent of the hospitals do not have separate budgets for their nursing departments, and only 13 per cent of the hospitals have separate budgets. It is recommended that the planning and execution of the nursing administration be delegated to the pertinent administrators in order to bring about improved proved performances and activities in nursing services.

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