• Analytical Science and Technology
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• v.18 no.6
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• pp.475-482
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• 2005

The expression of uncertainty applied to the chemical analysis is highly recommended with increasing demands upon the systematic quality assurance and control(QA/QC) with ISO 17025. For the quantification of quality source, 7 major common sources of uncertainty, normally contributing to the quality of the chemical analysis, were selected from QA/QC literatures of chemical analysis. They were classified into repeatability, drift, uncertainty in standards, linearity of calibration, homogeneity, stability of sample, and matrix effect. And, the quantification of the sources by means of measurement uncertainty was proposed as a prerequisite steps for QA/QC. Examples applied to the quantification procedures of modelling, combination and expression of standard uncertainty for the 7 major common sources were presented as a reference guide for QA/QC in chemical analysis.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.1
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• pp.66-75
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• 2010

With the advances in ubiquitous service infrastructure, healthcare services have drawn attention as one of promising application domains. In ubiquitous healthcare services, patients or care-givers as well as medical personnel are asked to play their roles and, in addition, the information system is supposed to have active roles. In medicine, clinical protocols have been developed and put into practice in order to reduce treatment variances and assure the service quality. In the same token, clinical protocols on ubiquitous service practices are need to be developed which takes into account both the clinical details and the ubiquitous service functionality. This paper introduces a clinical protocol modeling methodology which pays attention to participants and their tasks including contextual information. The proposed method has been successfully applied to a real application domain, OAB(overactive bladder) syndrome patient care to see how it builds a clinical protocol.

• Journal of the Korea Concrete Institute
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• v.18 no.6 s.96
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• pp.811-817
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• 2006

The primary purpose of this study is to estimate the guaranteed strength and construction quality of the combined high flowing concrete which is used in the slurry wall of underground LNG storage tank. The required compressive strength of this type of concrete become generally known as a non economical value because it is applied the high addition factor for variation coefficients and low reduction factor under water concrete. Therefore, after estimation of the construction quality and guaranteed strength in actual site work, this study is to propose a suitable equation to calculate the required compressive strength in order to improve its difference. Application results in actual site work are shown as followings. The optimum nix design proportion is selected that has water-cement ratio 51%, sand-aggregate ratio 48.8%, and replacement ratio 42.6% of lime stone powder by cement weight. Test results of slump flow as construction quality give average 616~634mm. 500mm flowing time and air content are satisfied with specifications in the rage of 6.3 seconds and 4.0% respectively. Results of strength test by standard curing mold show that average compressive strength is 49.9MPa, standard deviation and variation coefficients are low as 1.66MPa and 3.36%. Also test results by cored cylinder show that average compressive strength is 66.4MPa, standard deviation and variation coefficients are low as 3.64MPa and 5.48%. The guaranteed strength ratio between standard curing mold and cored cylinder show 1.23 and 1.32 in the flanks. It is shown that applied addition factor for variation coefficients and reduction factor under water concrete to calculate the required compressive strength is proved very conservative. Therefore, based on these results, it is proposed new equation having variation coefficients 7%, addition factor 1.13 and reduction factor 0.98 under water connote.

• Radiation Oncology Journal
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• v.25 no.4
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• pp.249-260
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• 2007

Purpose: In order to enhance the quality of IMRT as employed in Korea, we developed a remote monitoring system. The feasibility of the system was evaluated by conducting a pilot study. Materials and Methods: The remote monitoring system consisted of a head and neck phantom and a user manual. The phantom contains a target and three OARs (organs at risk) that can be detected on CT images. TLD capsules were inserted at the center of the target and at the OARs. Two film slits for GafchromicEBT film were located on the axial and saggital planes. The user manual contained an IMRT planning guide and instructions for IMRT planning and the delivery process. After the manual and phantom were sent to four institutions, IMRT was planed and delivered. Predicted doses were compared with measured doses. Dose distribution along the two straight lines that intersected at the center of the axial film was measured and compared with the profiles predicted by the plan. Results: The measurements at the target agreed with the predicted dose within a 3% deviation. Doses at the OARs that represented the thyroid glands showed larger deviations (minimum 3.3% and maximum 19.8%). The deviation at OARs that represented the spiral cord was $0.7{\sim}1.4%$. The percentage of dose distributions that showed more than a 5% of deviation on the lines was $7{\sim}27%$ and $7{\sim}14%$ along the horizontal and vertical lines, respectively. Conculsion: Remote monitoring of IMRT using the developed system was feasible. With remote monitoring, the deviation at the target is expected to be small while the deviation at the OARs can be very large. Therefore, a method that is able to investigate the cause of a large deviation needs to be developed. In addition, a more clinically relevant measure for the two-dimensional dose comparison and pass/fail criteria need to be further developed.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.6
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• pp.131-138
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• 2014

The steel structure fabrication plant certification program was enacted as a part of the construction technology management act, article 24-3, to improve the quality of steel construction after the decay falling accident of Seongsu Bridge in 1994. However, the national certification program for structural precast concrete that is a prefabricated construction products produced by casting concrete in plant is not implemented yet. So, to introduce the proper certification system for precast concrete, the quality certification programs of North America, Europe and Japan are surveyed. In North America, the organizations that manage the plant certification programs are PCI, NPCA, CPCI and so on. Sales of precast concrete elements in Europe are governed by the construction products regulation 305/2011. Therefore, CE marking is mandatory from July 2013 for all construction products including precast concrete. In Japan, precast concrete products used in civil engineering are certificated by JIS mark, product certification system and plants for manufacturing precast concrete building elements are audited by Japan Prefabricated Construction Suppliers and Manufacturers Association. Based on these survey studies, in this paper is described an adaptation of precast concrete plant certification to comport with the certification system in Korea.

• International Journal of Highway Engineering
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• v.10 no.3
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• pp.179-188
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• 2008

This study was performed as part of the development of the payment adjustment regulations for ensuring high performance of concrete pavements. The objectives of this study were to develop the reasonable quality measurement approaches for the implementation of the payment adjustment regulations and to propose the methods to determine the quality dependent pay factors. First, by using the statistics the slab thickness measurement data was analyzed and the methods to determine the allowable measurement errors, the proper measurement spacing, and the selection of the measurement location were proposed. In addition, to suggest the reasonable methods to determine the pay factors, by using the data of the slab thickness and concrete flexural strength, the pay factors based on the PWL(Percent Within Limits) method used in the USA were compared with those obtained considering the normal probability distribution and t distribution. Finally, the most appropriate method to determine the pay factors was proposed.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.556-558
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• 2005

SLA(Service Level Agreement)는 최근 들어 IT서비스를 받는 고객들에게 서비스 보장에 대한 명확한 계약과 일정수준 이상의 서비스 관리 제공으로 의무화 추세가 증가되고 있다. 또한 서비스 공급자는 변화하는 고객의 요구사항을 직면하여 SLA의 적용을 통해 서비스 Quality를 높이는데 주력하고 있다. 특히 특정 가입자가 두지점 사이에 교환 설비를 거치지 않고 직접 연결하여 독점적으로 사용할 수 있는 전용회선 서비스는 End-To-End간의 품질보증을 기본 목적으로 하고는 있지만 저렴한 요금의 프레임릴레이 ATM, VPN등 대체서비스로의 이동이 이어지고 있어 고객 측면의 새로운 방안 제시가 필요한 실정이다.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.27-37
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• 2011

Currently, in the course of introducing rolling stocks, RAMS standard and management by system engineering method apply to rolling stock system. Technical elements and results applied in system introduction phase are just used in acquisition stage, and these are not applied to the standard in railway site. Therefore, it is difficult to apply to standardized technology and quality assurance measure. Due to the establishment of the EU, railway operation system is internationalized and the international railway standards are being discussed in various ways. In addition, standardization is expanded from manufacture to operation and maintenance. It is to provide consistent standard in quality, cost calculation of maintenance technology, maintenance technology and quality assurance in case of international railway safety incidents. Therefore, this study is to find technology, quality and cost management model to be used for choosing railway-operation guidance by considering how technologies & quality have changed in system life cycle, compared with estimated standards, based on the technologies & quality-related result in the process of getting new rolling stocks and management guidance for operation & maintenance process.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.42
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• pp.73-85
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• 1997

In the product liability age the demand on quality is extremely high and inspection and test are automated. The process capability indices $C_p, {\;}C_{pk}$ and p control chart widely used to provide unitless measure of process performance and process control. Traditional process capability indices $C_p, {\;}C_{pk}$ do not represent the process variation from target value. The convention p chart for control of fraction nonconforming becomes inadequate when the fraction nonconforming becomes very small such as PPM level production system. This paper proposes process performance measure considering quadratic loss function and cumulative counts control chart for control of PPM level production system.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2004.11a
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• pp.33-35
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• 2004

방사선치료를 위한 고에너지 광자선의 품질관리를 위해 사용하는 TLD의 광자선 선질에 대한 에너지 의존도를 몬테카를로 모사법을 사용하여 평가하였다. IAEA 선량보증사업에 이용되는 LiF TLD 및 홀더를 EGS4기반의 사용자 코드인 DOSIMETER 와 MCNP4C 몬테카를로 코드를 사용하여 기하학구조를 구성하고, Co, 4, 6,10 밑 15 MV 광자선을 시뮬레이션하였다. DOSIMETER계산 결과를 통해 TLD의 에너지 보정인자가 실험 데이터와 일치함을 확인할 수 있었으며, 이와 별도로 캡슐에 의한 교란량도 무시할 수 없음을 발견하였다.