• Journal of Radiation Industry
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• v.7 no.1
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• pp.7-14
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• 2013

In this study, we investigated the applicability of the photostimulated luminescence (PSL), thermoluminescence (TL) and electron spin resonance (ESR) methods for various foods. The analysed samples consist of 11 items including dried fruits (6 items) and mushrooms (5 items). To compare between non-irradiated and irradiated food, all samples were irradiated with $^{60}Co$ gamma-ray source. In PSL study, the photon counts of all the unirradiated sample were identified negative (lower than 700). The photon counts irradiated (1, 5, 10 kGy) dried date-palm, dried jujube and mushrooms (Auricularia auricula, Phellinus linteus and Sarcodon aspratus) showed positive (higher than 5,000) and the results for the other samples were negative or intermediate (>700 and >5,000). In TL analysis most of items can be applicable to detect irradiated foods because of showing TL ratio above 0.1. The glow curves by TL method were estimated in the range of $150{\sim}250^{\circ}C$ in irradiated samples. In ESR measurements, the intensity of ESR signal (single-line) increased as the dose of irradiation increased. In particular, the specific ESR signals of irradiation-induced radical were detected in dried papaya, dried date-palm, dried banana, dried pineapple and S. aspratus. According to the results, PSL, TL and ESR methods were successfully applied to detect the irradiated foods. It is concluded that PSL, TL and ESR methods are suitable for detection of irradiated samples and a combined method is recommendable for enhancing the reliability of detection results.

• Journal of the Korean Geotechnical Society
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• v.26 no.7
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• pp.17-24
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• 2010

Load Resistance Factor Design method is used increasingly in geotechnical design world widely and resistance factors for drilled shafts are suggested by AASHTO. However, these resistance factors are determined for intact rock conditions; by comparison, most of bedrocks in Korea have weathered condition, so that applying the AASHTO resistance factors is not reasonable. Thus, this study suggests the proper resistance factors for design of drilled shaft in Korea. The 22 cases of pile load test data from 8 sites were chosen and reliability-based approach is used to analyze the data. Reliability analysis was performed by First Order Second Moment Method (FOSM) applying 4 bearing capacity equations. As a result, when the Factor of Safety (FOS) was selected as 3.0, the target reliability indexes (${\beta}_c$) were evaluated as 2.01~2.30. Resistance factors and load factors are determined from optimization based on above results. The resistance factors ranged between 0.48 and 0.56 and load factors for dead load and live load are evaluated as approximately 1.25 and 1.75 respectively. However, when the target reliabilities are considered as 3.0, the resistance factors are evaluated as approximately 50% of the results when the target reliability index was 2.0.

• Journal of Venture Innovation
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• v.7 no.2
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• pp.143-152
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• 2024

Recently, as a lot of software with AI functions has been developed, the number of software products with various prediction functions is increasing, and as a result, the importance of software quality has increased. In particular, as consideration for functional safety of products with AI functions increases, software quality management is being conducted at a national level. In particular, the GS Quality Certification System is a quality certification system for software products that is being implemented at the national level, and the GS Certification System is also researching quality evaluation methods for AI products. In this study, we attempt to present an evaluation model that satisfies the basic conditions of software quality based on international standards among the various quality evaluation models presented to verify software reliability. Considering the software quality characteristics of the artificial intelligence sector, we study quality evaluation models, diagnose quality, and predict failures. .In this study, we propose an international standard model for artificial intelligence based on the software reliability growth model, present an evaluation model, and present a method for quality diagnosis through the model. In this respect, this study is considered to be important in that it can predict failures in advance and find failures in advance to prevent risks by predicting the failure time that will occur in software in the future. In particular, it is believed that predicting failures will be important in various safety-related software.

• Journal of the Korea Concrete Institute
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• v.23 no.4
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• pp.495-501
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• 2011

The load combinations in current KCI Design Code are determined with reference to those in ACI 318-05, which adopts the LRFD (load and resistance factor design) format. The load and resistance factors in LRFD format should be determined to meet the required levels of reliability index or probability of failure for various predetermined failure modes, which are also based on the statistical data reflecting locality and contemporary situation. However, the current KCI Design Code has been written utilizing foreign data, because of insufficiency in accrued data in Korea. This study considered the current safety levels of KCI Code based on published domestic data to evaluate appropriateness of the current KCI regulations. Based on the calibrated reliability index of the existing Code, the new resistance factors are suggested. The results presented in this paper can be considered as a basic research for establishment of unique design format for future Korean Codes.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.8
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• pp.759-765
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• 2016

The PTO (Power Take-Off) shaft for aircraft, with welded construction using multiple thin membranes, was developed in the 1950s to improve the elasticity of the part. As it is lightweight, stable at high speeds, and has good flexibility, it is used in most of the fighter aircraft. It connects the AMAD (aircraft mounted accessory drive) gearbox with the EMAD (engine mounted accessory drive) gearbox and transmits the rotational power between them. It operates in the high speed range of 10,000-18,000 rpm. In this study, the safety of the PTO shaft made of Ti alloy was investigated using finite element analysis, and the ability to transmit power was demonstrated through a high-cycle fatigue test conducted in a laboratory. Further, the life of the ball joints of the aircraft under high-cycle fatigue test conditions was predicted, and the wear characteristics were analyzed.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.364-367
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• 2008

Earthwork is very equipment-intensive task and researches related to automated excavation have been conducted. There is an issue to secure the safety for an automated excavating system. Therefore, this paper focuses on how to improve safety for semi- or fully-automated backhoe excavation. The primary objective of this research is to develop object detection algorithm for automated safety system in excavation work. In order to satisfy the research objective, a diverse sensing technologies are investigated and analysed in terms of functions, durability, and reliability and verified its performance by several tests. The authors developed the objects detecting algorithm for user interface program using laser sensor. The results of this study would be the basis for developing the automated object detection system.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.6
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• pp.88-94
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• 2015

Large-scale petrochemical and power plants has increased demanting wireless technology for continuous monitoring. However, the current USN technologies, such as ZigBee and Bluetooth, are lackof reliability and security. Therefore, there is a strong need to apply a new wireless technology standard of the ISA. In this study, a petrochemicalplant safety management system based on the ISA wireless transmitter isdeveloped. ISA100.11a communication module and LTE communication module equippedwith an explosion-proof wireless transmitter are developed. A petrochemicalplant safety management system is built based on the IoT technologies. Thedeveloped system is verified through a wide range of testing and thus, on-siteapplicability is proved.

• Special Issue of the Society of Naval Architects of Korea
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• 2009.09a
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• pp.107-114
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• 2009

In the recent large block are used to build the ship to improve productivity. For this reason, two or more floating cranes that are connected in parallel is the trend. Typically, when working with floating crane load safety factor is considered. Even in the parallel operation, load safety factor is calculated similar to working alone. For this reason, operations do not guarantee the reliability or excessive safety factor applied. Therefore, the subdivided cases for calculating the safety factor are defined when parallel connected floating cranes are operated. Based on those cases, the operation standard is made about procedure using parallel connected floating cranes. And to verify this, dynamics simulation was performed for verification using the dynamics simulation program.

• Journal of the Korean Institute of Gas
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• v.26 no.5
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• pp.10-15
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• 2022

Currently, some urban gas companies are conducting their own gas AMI meter verification projects, along with the demonstration of gas AMI (Advanced Metering Infrastructure) meters under the supervision of the government. There are many positive factors such as remote meter reading and ensuring user gas safety through AMI meter installation, but on the other hand, there are also many problems such as battery discharge, expensive price, and decreased reliability of remote meter data. This study sought various improvements in gas AMI meters along with prevention of serious civil disasters by preemptively eliminating structural safety problems and potential risks from gas leakage due to the expansion of gas AMI meters, and it is expected that this study will contribute to the government's policy to advance gas AMI.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.2
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• pp.55-62
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• 2012

Convergence of information technology (IT) and medical devices enables people to measure health-related information ubiquitously, such as measuring blood glucose at home and checking cardiac signals during exercise and it allows us to access to medical care anywhere and anytime. Nowadays, the market for U-healthcare medical devices is growing rapidly, but guidelines for the evaluation of safety and effectiveness of such devices remain to be formulated. We performed a study on the development of safety and performance evaluation method for portable, hand-held, U-healthcare medical devices. We reviewed current guidelines and standards for home-health devices from the Korea Food and Drug Administration (KFDA) and related international committees such as the ISO/IEEE and CE. We summarized the test methods and items for the evaluation of safety and performance related to U-healthcare medical devices from the above guidelines and standards. We defined requirements for a U-healthcare medical device to demonstrate good performance. In conclusion, we propose an evaluation method for U-healthcare medical devices, which will help improve the safety and reliability of these devices.