Water utilities are making various efforts to reduce water losses from water networks, and an essential part of them is to recognize the moment when a pipe burst occurs during operation quickly. Several physics-based methods and data-driven analysis are applied using real-time flow and pressure data measured through a SCADA system or smart meters, and methodologies based on machining learning are currently widely studied. Water utilities should apply various approaches together to increase pipe burst detection. The most intuitive and explainable water balance method and its procedure were presented in this study, and the applicability and detection performance were evaluated by applying this approach to water supply pipelines. Based on these results, water utilities can establish a mass balance-based pipe burst detection system, give a guideline for installing new flow meters, and set the detection parameters with expected performance. The performance of the water balance analysis method is affected by the water network operation conditions, the characteristics of the installed flow meter, and event data, so there is a limit to the general use of the results in all sites. Therefore, water utilities should accumulate experience by applying the water balance method in more fields.

Measuring the concentration of corrosion products or nuclear fission products (FPs) in molten salts is crucial for pyroprocessing and molten salt reactors. Electrochemical analysis methods that can be performed in situ offer significant advantages for monitoring the concentration of corrosion products or FPs in molten salts. A microelectrode is an electrode with a length of several tens of micrometers on one side. The use of a microelectrode for electrochemical analysis has several advantages due to its small size, including rapidly reaching the limiting current regardless of the scan rate, immediate attainment of the limiting current upon applying an overpotential for instant monitoring within milliseconds, accurate measurement even in low convection systems, a small iR drop resulting from low flowing current and high signal accuracy, and high current density resulting in a high signal-tonoise ratio (SNR). Among various methods for making microelectrodes, techniques involving cutting a thin wire or using capillaries (such as the dual-bore capillary and pulled glass capillary methods) require precise manual skills and experience. Therefore, the results may vary depending on the maker’s skill level, and it can be difficult to control the electrode’s area, thickness, and surface uniformly. Recent research has focused on using semiconductor processes to fabricate microelectrodes, where CVD, metal sputtering, photolithography, and etching processes work together to deposit, refine, and shape the required material on a silicon wafer to create microelectrodes. However, the durability of microelectrodes produced this way is still low (usable for about 15-30 minutes), and there is no clear research on the degradation mechanism over time. To verify the proper operation of the fabricated microelectrodes, cyclic voltammetry (CV) is performed at various scan rates (from 10 mVs-1 to 2 Vs-1), and chronoamperometry (CA) is also examined to confirm whether the electrodes rapidly reach a steady-state current. After confirming their proper operation, CV is continuously measured until the microelectrodes are destroyed in a LiCl-KCl solution containing a small amount of FPs (Sm 340 mM) at 450°C. By observing changes in the electrical signal of the microelectrodes over time, the durability is evaluated, and the mechanism of performance degradation of the electrode is discovered. The experiment is then repeated by gradually increasing the temperature by 30°C from 450°C up to 600°C to observe the changes with temperature. This study provides basic information for future microelectrode experiments, and by diagnosing the cause of destruction, a more durable microelectrode structure can be manufactured.

Timely detection of nuclear activity is important for the management and supervision of nuclear materials, and inspections on North Korea as a method of safety measures for this monitoring system seem to be a not far future in the rapidly changing North Korea relationship. However, a simpler and more reliable monitoring device is required since the inspection period is limited and the possibility of revisiting is unclear. The seal is a simple but easily used security device for monitoring forgery and falsification in the IAEA. IAEA presents matters related to 1) project engineering, 2) remote monitoring, and 3) seal development as the three major tasks of the Department of safeguards and Division of Technical Support. The importance of development, modernization, and application of new seal devices is emphasized, and advanced sealing and identification system development is in progress at many research institutes such as JRC, ISCN, and JAEA. Since the existing seal devices used by IAEA and KINAC can only be confirmed through on-site inspections for damage, it is difficult to respond immediately in the event of similar situations such as theft of nuclear materials and loss of continuity of knowledge. Unlike facilities that comply with the requirements for safety measures, such as domestic nuclear facilities, in the case of facilities subject to denuclearization, it is very likely that various hazardous environments will exist that make it difficult to apply safety measures. Hence, a real-time seal device has developed through prior research due to the high possibility of situations in which Continuity of Knowledge (COK) is not maintained, such as damage, malfunction, and power loss of sealing and monitoring equipment. Through previous studies, the real-time seal device was loaded with server-based operating software and improved its performance by utilizing feedback from real users (KINAC) after use. In this study, the effectiveness of the previously developed sealing system was verified through performance evaluation, and the authentication of the equipment was secured through environmental tests.

The Cu2ZnSn(SxSe1-x)4 (CZTSSe) absorbers are promising thin film solar cells (TFSCs) materials, to replace existing Cu(In,Ga)Se2 (CIGS) and CdTe photovoltaic technology. However, the best reported efficiency for a CZTSSe device, of 13.6 %, is still too low for commercial use. Recently, partially replacing the Zn2+ element with a Cd2+element has attracting attention as one of the promising strategies for improving the photovoltaic characteristics of the CZTSSe TFSCs. Cd2+ elements are known to improve the grain size of the CZTSSe absorber thin films and improve optoelectronic properties by suppressing potential defects, causing short-circuit current (Jsc) loss. In this study, the structural, compositional, and morphological characteristics of CZTSSe and CZCTSSe thin films were investigated using X-ray diffraction (XRD), X-ray fluorescence spectrometer (XRF), and Field-emission scanning electron microscopy (FE-SEM), respectively. The FE-SEM images revealed that the grain size improved with increasing Cd2+ alloying in the CZTSSe thin films. Moreover, there was a slight decrease in small grain distribution as well as voids near the CZTSSe/Mo interface after Cd2+ alloying. The solar cells prepared using the most promising CZTSSe absorber thin films with Cd2+ alloying (8 min. 30 sec.) exhibited a power conversion efficiency (PCE) of 9.33 %, Jsc of 34.0 mA/cm2, and fill factor (FF) of 62.7 %, respectively.

본 논문은 지상파 기반의 측위·항법·시각(PNT, Positioning, Navigation, and Timing) 서비스의 대표격인 eLoran(enhance LOng RAnge Navigation) 시스템의 시각동기 성능 모니터링 시스템의 설계에 관한 것으로서, GNSS(Global Navigation Satellite System)의 신호 취약성에 따른 시각동기시스템의 한계에 대해 설명하고, 이에 대한 백업시스템으로 대표적 지상파항법시스템인 eLoran 시스템의 시각동기 성능모니터링 시스템에 대해 중점적으로 다룬다. eLoran 시스템을 이용한 시각동기 서비스 및 이에 대한 성능감시를 위한 보정기준국(dLoran, differential Loran) 관점에서의 시각동기 성능모니터링 시스템의 구성과 그 요구성능에 대해 설명한다. 또한 eLoran 테스트베드 환경 내 시각동기 모니터링 시스템의 장기 시범운영을 통해서, eLoran 시각동기서비스의 성능을 분석한다. 시각동기 성능모니터링 시스템을 이용한 성능 분석결과 보정 전 43.71 ns, 보정 후 22.52 ns (rms)의 시각정밀도를 나타내었으며, 이를 통해서 정밀시각 동기원으로 eLoran 서비스가 충분히 GPS 백업 시각동기시스템으로 활용이 가능함을 확인할 수 있었다.

Many companies make considerable efforts in implementing supply chain management systems to increase their competitiveness. In particular, there are significant investments in their ICT (Information and Communication Technology) and supply chain. However, considerable diversity exists in how well firms have been able to assimilate ICT and leverage the business value of it. In addition, studies on supply chains, particularly Real Time Enterprise (RTE) competence, which is cited for rapid information sharing and dynamic capabilities for each role in the supply chain, are insufficient. The purpose of this paper is to explore and evaluate effect of ICT utilization capabilities, including ‘ICT internal cooperative capabilities’ and ‘ICT operational flexibility capabilities’, on RTE capabilities (flexibility, visibility and prediction) and supply chain performance. To validate the research model proposed in the study, survey was conducted on companies using ICT along the supply chain of manufacturing industries. 216 data were used, SPSS and AMOS were used for the analysis methods. Study results showed that ICT internal collaboration capabilities affect agility, one of RTE capabilities, but not visibility and prediction, and ICT operational flexibility capabilities have affected all three RTE capacities. And, RTE capabilities had a huge impact on supply chain performance as expected. In this paper, it has been found that the ICT capabilities in manufacturing are an important factor in improving RTE capabilities that are important in the supply chain and improving the performance of the supply chain.

목적 : 온도가 변색렌즈의 성능에 미치는 영향이 있는지 확인하여 변색렌즈 공급자와 수요자를 위한 기초 자료를 제시하고자 한다. 방법 : 굴절률 1.56과 1.60의 변색렌즈 12종을 대상으로 하였다. 온도 조절 유지 장치를 이용하여 20ﾟC, 30ﾟC, 40ﾟC, 50ﾟC 온도에서 1분에서 5분간 자외선을 조사한 후 농도를 측정하였다. 농도 분석은 변색과정을 카메라를 이용하여 동영상으로 촬영한 후 포토샵 프로그램(Adobe Photoshop CS5)을 이용하여 중앙부분의 명도를 측정하였다. 결과 : 20ﾟC 환경에서 1분간 자외선을 조사한 결과 69%, 76%(2분), 78%(3분), 78%(4분), 79%(5분)로 나타났고, 50ﾟC에서 1분간 자외선을 조사한 결과 44%, 46%(2분), 46%(3분), 48%(4분), 50%(5분)로 나타났다. 1.56은 20ﾟC 환경에서 1분간 자외선을 조사한 결과 73%, 81%(2분), 84%(3분), 84%(4분), 85%(5분)로 나타나 온도 20ﾟC에서 가장 농도가 높게 나타났고, 온도 50ﾟC에서 41%(1분), 43%(2분), 43%(3분), 44%(44분), 47%(5분)로 나타났다. 1.60 은 20ﾟC에서 1분간 자외선을 조사한 결과 79%, 84%(2분), 85%(3분), 85%(4분), 85%(5분%)로 역시 온도 20ﾟC 에서 가장 높게 나타났고, 온도 50ﾟC에서 41%(1분), 41%(2분), 43%(3분), 43%(4분), 45%(5분)로 나타났다. 20ﾟC 환경에서 코팅방식으로 제조된 변색렌즈는 79%의 농도를 보였고, 모노머방식은 76%의 농도를 보였다. 30ﾟC에서 코팅방식은 74%, 모노머 방식은 72%, 40ﾟC에서 코팅방식은 68%, 모노머방식은 66%, 40ﾟC에서 코팅방식은 68%, 모노머방식은 66%, 50ﾟC에서 코팅방식은 52%, 모노머방식은 48%의 농도를 보였다. 결론 : 동일한 시간 동안 자외선을 조사했을 때 온도가 증가할수록 변색의 농도는 감소하고, 1.56과 1.60 굴절률 모두에서 20ﾟC로부터 온도가 증가할수록 변색 농도가 감소하며, 모노머방식으로 제조된 변색렌즈보다 코팅방식으로 제조된 변색렌즈가 동일한 온도에서 더욱 진하게 변하는 것을 알 수 있었다.

Due to dramatic changes in the trend of corporate management in economics, labor and government, companies are being asked to adapt creative and innovative organizational culture in order to keep sustainability. Under the circumstances, flexible working hour becomes one of very effective method for organization culture improvement. Recently, M company has introduced the new policy of working hours that employees can choose a couple of different time options depending on their personal situations. And it turns out to be very effective to work & life balance, increasing organizational vitality, improving efficiency of business and productivity, recruitment of core human resources, and prevention of deviation; both team and personal performance levels has significantly improved. Therefore, it is highly recommended to adapt flexible working policies for companies seeking for a long term, sustainable corporate vision.

The Air-shiter is a new product possible ventilation at the same time cooling or heating with combined refrigerator and heat recovery ventilator. And a key device of this system is the air shifter. The air shifter device is to convert the outdoor air, room air, supply air and exhaust air flow. Therefore, an experimental study has been carried out to investigate the operating performance for this system. The results, it is possible to ventilate at the same time of heating by outside air above 30℃ in summer. and of heating by outside air within 3℃ in winter. The indoor discharge temperature is over 40℃, and the coefficient of performance is 3.4 in winter.

Due to dramatic changes in the trend of corporate management (economic, labor, government), companies are being asked to adapt creative and innovative organizational culture in order to keep sustainability. Under the circumstances, flexible working hour becomes one of very effective method for org culture improvement. Recently, M company has introduced the new policy of working hours that employees can choose a couple of different time options depending on their personal situations. And it turns out to be very effective(work & life balance, increasing organizational vitality, improving efficiency of business and productivity, Recruitment of core human resources, Prevention of deviation); both team and personal performance levels has significantly improved. Therefore, it is highly recommended to adapt flexible working policies for companies seeking for a long term, sustainable corporate vision.

A self-powered time-temperature indicator (TTI) was optimized to enhance the performance of the TTI by modifying a biofuel cell using different immobilization, redox mediators, and status of electrode. The performance of the TTI was measured by output voltage of the TTI. The enzymes and combinations of lacasse mediators (HBT (1-hydroxybenzotriazole), Rupy (Bis-(bipyridine)-(5-aminophenanthroline) ruthenium bis (hexafluorophosphate)), MB (Methylene blue), SDP (4,4- sulfonyldiphenol)) and glucose oxidase mediators (FA (Ferroceneboxaldehyde), DBQ(2,5-dihydroxybenzoquinone), HQS (8-hydroxyquinoline-5sulfonic acid hydrate), FHFP (Ferrocenium hexafluorophosphate)) were immobilized with stabilizers (pyrrole) on a glassy carbon electrode by electrodeposition by applying a square wave, cross-linking and physical immobilization. MWCNTs were used to modify glassy carbon electrodes. MWCNTs coated electrodes produced higher output voltage than uncoated electrodes. The optimum and stable performance of the self-powered TTI was that the output voltage of 64 mV and duration time was 3hr at 25°C, when the combination of Rupy, MB for laccase mediators and HQS, FHFP for glucose oxidase mediators were immobilized on MWCNTs coated electrodes by applying a square wave method. In the application, the concentrations of enzyme and glucose were adjusted to prolong the shelf-life of TTI at much lower output voltage.

국가차원의 슈퍼컴퓨팅 성능수요 예측은 슈퍼컴퓨터를 활용하는 계산과학분야 의 연구자나 연구개발 인프라를 구축⋅운영하고 있는 전문기관, 과학기술 인프라구축을 주도 할 정부기관에 있어서 매우 중요한 정보이다. 본 연구는 그동안 진행되었던 슈퍼컴퓨터 성능관련 예측활동 분석을 통해 과학기술 역량 에 영향을 미치는 요인들을 도출하고 이를 슈퍼컴퓨터 기술진보 추세에 적용한 복합 예측모 형을 제안하였다. 횡단면분석에서는 슈퍼컴퓨팅 성능에 영향을 미칠 것으로 판단되는 GDP, GERD, 연구원수, SCI논문수를 고려한 다중회귀분석을 수행하였다. 그리고 횡단면분석 결과 에 Top500 자료의 성능(Rmax)값을 이용한 시계열분석을 통해 도출된 기간별 기술진보율을 곱하여 슈퍼컴퓨터의 성능을 예측하였다. 제안된 예측모형을 바탕으로 세계 슈퍼컴퓨터 500위의 시계열자료를 이용하여 한국이 2016년에 보유해야 할 슈퍼컴퓨터 성능규모를 예측하였다. 횡단면분석과 기술진보율을 적 용하여 2016년 한국의 슈퍼컴퓨팅 성능수요를 예측해본 결과 현재의 추세를 이용할 경우 15～30PF 정도, 목표 국가수준의 추세를 이용할 때 20～40PF 정도의 컴퓨팅 역량이 필요할 것으로 예측되었다. 이 결과는 단순 회귀분석을 적용한 결과인 9.6PF와 횡단면분석을 적용 한 결과인 2.5PF와 큰 차이를 나타내었다.

본 논문에서는 물성이 균일하지 않은 반무한 고체영역의 탄성파속도 분포를 재구성하기 위한 시간영역 Gauss-Newton 전체파형 역해석 기법을 소개한다. 반무한 영역을 유한 계산영역으로 치환하기 위하여 유한영역의 경계에 수치적 파동흡수 경계조건인 perfectly-matched-layers(PMLs)를 도입하였다. 이 역해석 문제는 PML을 경계로 하는 영역에서의 탄성파동방정식을 구속조건으로 하는 최적화 문제로 성립되며, 표면에서 측정된 변위응답과 혼합유한요소법에 의해 계산된 응답간의 차이를 최소화함으로써 미지의 탄성파속도 분포를 결정한다. 이 과정에서 Gauss-Newton-Krylov 최적화 알고리즘과 정규화기법을 사용하여 탄성파속도의 분포를 반복적으로 업데이트하였다. 1차원 수치예제들을 통해 Gauss-Newton 역해석으로 부터 재구성된 탄성파속도의 분포가 목표값에 충분히 근사함을 보였으며, Fletcher Reeves 최적화 알고리즘을 사용한 기존의 역해석 결과에 비해 수렴율이 현저히 개선되고 계산 소요시간이 단축됨을 확인할 수 있었다.

단시간 근로자에 대한 수요가 증가함에 따라 기업에서는 단시간 근로자에 대한 관심이 높아지고 있다. 단시간 근로자를 활용하는 것은 기업의 노동비용 절감과 인력운영의 유연성을 높일 수 있다는 장점이있는 반면, 인력관리 비용의 증가와 업무 생산성 유지의 애로가 있다는 단점이 제기되고 있다. 따라서 이들의 업무성과를 지속적으로 유지하기 위해서는 직무만족과 조직몰입을 유지하는 것이 중요하다는 주장이 제기되고 있다. 본 연구의 목적은 단시간 근로자의 직무만족과 조