• Structural Engineering and Mechanics
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• 제82권5호
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• pp.557-569
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• 2022

The retrofit of existing structures in high seismic zones is a crucial issue in the earthquake engineering field. The interest of the research community is particularly high for the structures that do not respect current seismic codes and present structural deficiencies such as poor detailing and lack of capacity design provisions. A reinforced concrete (RC) school building is used as case study to show the influence of different knowledge levels on the seismic retrofitting cost assessment. The safety assessment of the case study building highlights deficiencies under both vertical and seismic loads. By considering all the possible knowledge levels defined by the Italian such as by the European codes in order to derive the mechanical properties of the school building constitutive materials, the retrofit operations are designed to achieve different seismic safety thresholds. The retrofit structural costs are calculated and summed up to the costs for in-situ in tests. The paper shows how for the case study building the major costs spent for a large number of in-situ tests allows to save a consistent amount of money for retrofit operations. The hypothesis of demolition and reconstruction of the building is also compared in terms of costs with all the analyzed retrofit options.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.639-640
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• 2015

Traditional construction planning based on historical data and heuristic adjustment can no longer incorporate all the operational details and guarantee the expected performance. The variation between the expected and the actual production leads to cost overruns or delay. Although predicting reliable productivity on construction site is getting more important, the difficulty of this increases. In this regard, this paper suggested to develop BIM-integrated simulation framework. This framework could predict productivity dynamics by considering factors affecting on construction productivity at operational phase. We developed the following processes; 1) enabling a BIM model to produce input data for simulation; 2) developing the construction operation simulation; 3) running simulation using BIM data and obtaining productivity results. The BIM-integrated simulation framework was tested with structural steel erection model because steel erection work is one of the most critical process influencing on the whole construction budget and duration. We could improve to predict more dynamic productivity from this framework, and this reliable productivity helps construction managers to optimize resource allocation, increase schedule reliability, save storage cost, and reduce material loss.

• 국제학술발표논문집
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• The 5th International Conference on Construction Engineering and Project Management
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• pp.517-520
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• 2013

In construction operation, the temporary structure is used to support designed facilities or to provide work spaces for construction activities. Since the structure is used only during the construction operation, the operation may be given insufficient attention. The contractor is likely to try to save cost on the material and labor cost. This contractor's behavior frequently leads to construction accidents. In order to prevent accidents from the failure, the operation should be carefully monitored for identifying the effect of dynamics in the surrounding site area. Otherwise, any unexpected adversary effect could result in a very costly construction failure. This study presents the feasibility of the ubiquitous sensor network (USN) technology in collecting construction data during the construction operation of earth retaining walls. The study is based on the result at the Construction System Integration Laboratory (CSIL) at the Pusan National University. A USN-based system has been developed for monitoring the behavior of the temporary structure of earth retaining walls. The data collected from the sensors were used to understand the behavior of the temporary structure. The result of this study will be used in increasing the safety during the construction operation of retaining walls.

• Asian Pacific Journal of Cancer Prevention
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• 제14권3호
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• pp.2059-2065
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• 2013

This goal of this research was to evaluate the cost-effectiveness of the National Cancer Screening Program (NCSP) for breast cancer in the Republic of Korea from a government expenditure perspective. In 2002-2003 (baseline), a total of 8,724,860 women aged 40 years or over were invited to attend breast cancer screening by the NCSP. Those who attended were identified using the NCSP database, and women were divided into two groups, women who attended screening at baseline (screened group) and those who did not (non-screened group). Breast cancer diagnosis in both groups at baseline, and during 5-year follow-up was identified using the Korean Central Cancer Registry. The effectiveness of the NCSP for breast cancer was estimated by comparing 5-year survival and life years saved (LYS) between the screened and the unscreened groups, measured using mortality data from the Korean National Health Insurance Corporation and the National Health Statistical Office. Direct screening costs, indirect screening costs, and productivity costs were considered in different combinations in the model. When all three of these costs were considered together, the incremental cost to save one life year of a breast cancer patient was 42,305,000 Korean Won (KW) (1 USD=1,088 KW) for the screened group compared to the non-screened group. In sensitivity analyses, reducing the false-positive rate of the screening program by half was the most cost-effective (incremental cost-effectiveness ratio, ICER=30,110,852 KW/LYS) strategy. When the upper age limit for screening was set at 70 years, it became more cost-effective (ICER=39,641,823 KW/LYS) than when no upper age limit was set. The NCSP for breast cancer in Korea seems to be accepted as cost-effective as ICER estimates were around the Gross Domestic Product. However, cost-effectiveness could be further improved by increasing the sensitivity of breast cancer screening and by setting appropriate age limits.

• 보건행정학회지
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• 제22권1호
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• pp.29-48
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• 2012

The purpose of this study is to analyze medical expenses by decedents in their last year of life and compare them with those by survivors during the year 2008. This study is conducted firstly in Korea, except some studies focusing on medical cost of decedents from specific diseases. To study this, national health insurance(NHI) claims data was used with medicaid claims data. The study group(decedents) was selected from the insurance entitlement file who were dropped out from January to December of 2008. The control group(survivors) was selected from the entitlement file by stratified sampling with keeping age-sex composition of the study group. The medical expenses of decedents during one year before death were measured and compared with those of survivors by sex and age. And the medical expenses were analyzed by causes of death, and also the expenses were examined by each item of medical services. On average, the medical expense amounted to 11 million Korean Won per decedent during their last year of life in 2008. The medical expense per decedent was 9.3 higher than that of survivor. The death-related expense of under the age 35 was about 16 million Won, compared with 4 million Won in the case of over the age 95, in average. The death-related expense is higher in younger ages. This means that more medical resources are put in to save life in younger ages. Total death-related expenditure took 8.3 percent in total NHI expenditures. Of the death-related medical expenses, the largest one was injection-related cost which shares twenty five percent, and the second largest one was hospitalization charges, and then the third one was surgery cost. The results of this study suggested that we should pay attention to the medical expenses in the last of year of life when we study health care expenditure in Korea. In addition, we have to deliberate health care policy to cope with medical expenditures before death in more efficient way.

• 한국구조물진단유지관리공학회 논문집
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• 제23권2호
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• pp.10-19
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• 2019

염해에 콘크리트 구조물은 사용기간의 증가에 따라 내구성에 문제가 발생하므로 보수를 포함한 유지관리가 필수적이다. 일반적으로 결정론적인 방법으로 내구수명이 결정되고 이에 따라 유지관리비가 평가되고 있으나, 확률론적 유지관리 기법을 고려할 경우 연속적인 보수비용이 평가되므로 합리적인 유지관리가 가능하다. 기존의 확률론적 유지관리 기법에서는 정규분포만 고려되었으나, 본 연구에서는 초기 내구수명 및 보수에 따른 수명-확률함수에 로그함수를 고려할 수 있도록 개선되었으며, OPC 및 GGBFS를 사용한 콘크리트에 대하여 보수비용을 평가하였다. 로그 함수를 가지는 수명-확률함수는 중앙값 이전보다 이후에 미치는 영향이 지배적이므로 초기 내구수명 분포에 유리하며 전반적으로 낮은 보수비용을 도출할 수 있다. GGBFS를 사용한 콘크리트는 OPC 콘크리트 비하여 높은 내구수명과 낮은 보수횟수를 통하여 30% 수준으로 보수비가 감소하였다. 본 연구에서 도출된 확률론적 유지관기 기법은 정규분포 뿐 아니라 로그분포를 가지는 수명-확률함수를 초기 및 다양한 보수시기에 적용할 수 있는 장점을 가지고 있으며, 더욱 합리적인 보수비용을 도출할 수 있다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.1335-1341
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• 2011

Conserving clean air and removing contaminants and particular matters accumulated in the ventilation system of the subway stations are key issue for green railway environment. There is no national guideline or industrial regulations to sustain clean duct and ventilation system, which requires rapid reformation of cleaning procedure and system. In fact, accumulated various particular matters and dusts can occur secondary air contamination and become a primary health harm factor for subway passengers. This study investigates various duct cleaning technologies and trends. In additon, effective cleaning method with an automated robot device is proposed. In particular, current dust cleaning technologies and duct cleaning robots are analyzed based on their functions and feasibilities. The proposed design of automated device is expected to save the operating cost of subway HVAC system and sustain clean air environment.

• Restorative Dentistry and Endodontics
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• 제38권1호
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• pp.48-51
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• 2013

The autogenous tooth transplantation is an alternative treatment replacing a missing tooth when a suitable donor tooth is available. It is also a successful treatment option to save significant amount of time and cost comparing implants or conventional prosthetics. These cases, which required single tooth extraction due to deep caries and severe periodontal disease, could have good results by transplanting non-functional but sound donor tooth to the extraction site.

• 조명전기설비학회논문지
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• 제27권1호
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• pp.61-67
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• 2013

The turnout point system is installed to separate the main rail track from other tracks in rail load stations. It is also important to set up the switch point system to change the direction of the turnout point, to lead and change the direction of tracks. The switch point system can be negatively affected by heavy snow during winter seasons which can cause critical safety problems. Furthermore, the maintenance and repair of the conventional system is prohibitively expensive due to its complexity and high probability of failure. In this paper, an efficient switch point system is proposed which simplifies the equipment structure and lowers the cost for maintenance and repair, while improving safety and performance of the rail road system.

• 한국군사과학기술학회지
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• 제16권2호
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• pp.138-145
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• 2013

Airworthiness certification is a government certification for the military aircraft to safely attain, sustain and terminate flight and It is a mandatory process of qualifying the flight safety within the operational boundaries of a military aircraft. To save the manhour, time and cost for applying all the airworthiness certification criteria to the aircraft equipped with flight control switching mechanism development program, an identification of the risk and systematic assessment of risk is analysed. Airworthiness redesign actions so called software switching mechanism for the modified aircraft in the flight technology and electric system area are suggested to reduce the risk hazard index.