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.

Considering the non-linear behavior of structure and soil when evaluating a nuclear power plant's seismic safety under a beyond-design basis earthquake is essential. In order to obtain the nonlinear response of a nuclear power plant structure, a time-domain SSI analysis method that considers the nonlinearity of soil and structure and the nonlinear Soil-Structure Interaction (SSI) effect is necessary. The Boundary Reaction Method (BRM) is a time-domain SSI analysis method. The BRM can be applied effectively with a Perfectly Matched Layer (PML), which is an effective energy absorbing boundary condition. The BRM has a characteristic that the magnitude of the response in far-field soil increases as the boundary interface of the effective seismic load moves outward. In addition, the PML has poor absorption performance of low-frequency waves. For this reason, the accuracy of the low-frequency response may be degraded when analyzing the combination of the BRM and the PML. In this study, the accuracy of the analysis response was improved by adjusting the PML input parameters to improve this problem. The accuracy of the response was evaluated by using the analysis response using KIESSI-3D, a frequency domain SSI analysis program, as a reference solution. As a result of the analysis applying the optimal PML parameter, the average error rate of the acceleration response spectrum for 9 degrees of freedom of the structure was 3.40%, which was highly similar to the reference result. In addition, time-domain nonlinear SSI analysis was performed with the soil's nonlinearity to show this study's applicability. As a result of nonlinear SSI analysis, plastic deformation was concentrated in the soil around the foundation. The analysis results found that the analysis method combining BRM and PML can be effectively applied to the seismic response analysis of nuclear power plant structures.

Pacific herring, Clupea pallasii, a keystone species with significant ecological and commercial importance, is declining globally throughout much of its range. While traditional fishing equipment methods remain limited, new sensitive and rapid detection methods should be developed to monitor fisheries resources. To monitor the presence and quantity of C. pallasii from environmental DNA (eDNA) extracted from seawater samples, a pair of primers and a TaqMan® probe specific to this fish based on mitochondrial cytochrome b (COB) sequences were designed for the real-time PCR (qPCR) assay. The combination of our molecular markers showed high specificity in the qPCR assay, which affirmed the success of presenting a positive signal only in the C. pallasii specimens. The markers also showed a high sensitivity for detecting C. pallasii genomic DNA in the range of 1 pg~100 ng rxn-1 and its DNA plasmid containing COB amplicon in the range of 1~100,000 copies rxn-1, which produced linear standard calibration curves (r2=0.99). We performed a qPCR assay for environmental water samples obtained from 29 sampling stations in the southeastern coastal regions of South Korea using molecular markers. The assay successfully detected the C. pallasii eDNA from 14 stations (48.2%), with the highest mean concentration in Jinhae Bay with a value of 76.09±18.39 pg L-1 (246.20±58.58 copies L-1). Our preliminary application of molecular monitoring of C. pallasii will provide essential information for efficient ecological control and management of this valuable fisheries resource.

This study was carried out to study the effect of supplementary nitrogen fertilization application time according to regrowth date on growth date on growth characteristics, feed value, and productivity of Italian ryegrass (Lolium multiflorum Lam.; IRG) from 2019 to 2021 in Cheonan region. In order to determine the regrowth time, IRG was cut from experimental plots 3cm above soil level and the time when 1cm grew was judged as the regrowth time. The regrowth dates were February 15th and February 12th in 2020 and 2021 respectively. The experimental design was a randomized block design with three replications. The treatments were no fertilizer, immediately after the regrowth period, after 10 days of the regrowth period, and after 25 days of the regrowth period. Dry matter yield of IRG was significantly influenced by the supplementary N-fertilization application time. Dry matter yield was reduced for the delayed application time. The dry matter yield of immediately after the regrowth period was approximately 34.8 % higher than that no fertilizer application. In delaying the supplementary N-fertilization application time resulted in increased crude protein content. However, no significant statistical difference was neutral detergent fiber and acid detergent fiber(p>0.05). After wintering, productivity of IRG reduced for the delayed application time. Therefore, it is essential to application N-fertilizer immediately after the regrowth period for high productivity of IRG.

본 연구는 선박용 공기압축기의 상태기반보전 시스템에 필요한 이상치 탐지 알고리즘 적용에 대한 실험적 연구로서 고장모사 실험을 통해 시계열 전류 센서 데이터를 이용한 이상탐지 적용 가능성을 확인하였다. 고장 유형 10개에 대해 실험실 규모의 고장 모사 실험을 수행하여 정상 운전데이터와 고장 데이터를 구축하였다. 실험 결과 구축된 이상탐지 모델은 시계열 데이터의 주기에 변화를 유발하는 이상은 잘 탐지하는 반면 미세한 부하 변동에 대한 탐지 성능은 떨어졌다. 또한 오토인코더를 이용한 시계열 이상탐지 모델은 입력 시 퀀스의 길이와 초모수 조정에 따라 이상 탐지 성능이 상이한 것으로 나타났다.

본 연구는 수수 × 수단그라스 바이오에탄올 생산을 위한 적정 수확 시기 및 수확 후 재생과정에서 요구되는 적정 질소 시비 수준을 파악하기 위해 수행되었다. 포장 실험은 2017부터 2018년까지 실시했으며, 시험구 배치는 난괴법(RCBD)으로 여름 수확 후 질소 추비 수준을 달리하여(0, 50, 100, 150 kg N/ha; 0N, 50N, 100N, 150N) 처리하였다. 재생과정에서 canopy height은 2017년 여름 수확 후(DAT, day after summer harvest treatment) DAT23에서 DAT48로 경과함에 따라 약 3.0배, 2018년 DAT26에서 DAT48로 경과함에 따라 약 2.9배 신장하였다. 엽록소 함량은 재생과정 초기 질소 무처리구와 질소처리구간 유의한 차이가 나타났으나, DAT48 이후 처리 간 차이는 없었다. 여름 수확은 2017년 파종 후 61일 뒤, 2018년 파종 후 83일 뒤 각각 이루어졌으며 건물수량은 8.6Mg/ha, 11.0Mg/ha로 차이를 보였다. 생육시기별 2차 수확의 건물수량은 2017년의 경우 생육이 진전됨에 따라 꾸준히 증가하였으며, 2018년에는 DAT76까지 증가하였다. 2017년 DAT107에서 무처리구(9.0Mg/ha)에 비해 질소 처리구(12.3Mg/ha)에서 1.4배 높았으며, 무처리의 수량이 낮았던 2018년 DAT113에서는 무처리구(2.3Mg/ha)에 비해 질소 처리구 (5.6Mg/ha)로 2.5배 높았다. 수확물의 바이오에탄올 품질을 나타내는 바이오에탄올 수율(TEP)는 생육 후기 cellulose와 hemicellulose 비율 감소로 일부 줄어들었으나, 전체적인 TEP변화는 생육시기나 추비수준과 관계없이 5% 이내로 큰 차이는 없었다. 총 바이오에탄올 수량(total TEY)은 2017년 DAT107에서 7,944L/ha, 2018년 DAT76에서 7,163L/ha로 추정되었다. 따라서 TEY를 높이려면 수확물의 단위면적당 건물중을 증가시키는 재배방법이 필요하다. 여름 수확 후 충분한 재생을 위해서 필요한 질소 추비 수준은 100kg N/ha 이상이었으며, 2차 수확은 여름 수확 실시 후 2개월 이상 경과 한 이후 실시해야 한다.

Reliability analysis of the components frequently starts with the data that manufacturer provides. If enough failure data are collected from the field operations, the reliability should be recomputed and updated on the basis of the field failure data. However, when the failure time record for a component contains only a few observations, all statistical methodologies are limited. In this case, where the failure records for multiple number of identical components are available, a valid alternative is combining all the data from each component into one data set with enough sample size and utilizing the useful information in the censored data. The ROK Navy has been operating multiple Patrol Killer Guided missiles (PKGs) for several years. The Korea Multi-Function Control Console (KMFCC) is one of key components in PKG combat system. The maintenance record for the KMFCC contains less than ten failure observations and a censored datum. This paper proposes a Bayesian approach with a Dirichlet mixture model to estimate failure time density for KMFCC. Trends test for each component record indicated that null hypothesis, that failure occurrence is renewal process, is not rejected. Since the KMFCCs have been functioning under different operating environment, the failure time distribution may be a composition of a number of unknown distributions, i.e. a mixture distribution, rather than a single distribution. The Dirichlet mixture model was coded as probabilistic programming in Python using PyMC3. Then Markov Chain Monte Carlo (MCMC) sampling technique employed in PyMC3 probabilistically estimated the parameters’ posterior distribution through the Dirichlet mixture model. The simulation results revealed that the mixture models provide superior fits to the combined data set over single models.

공기 분위기하 UO2의 독특한 산화거동을 모사하기 위해 기존 Crackling Core Model (CCM)을 개선하였다. UO2가 U3O8으로 전환될 때 시간-전환율 곡선에서 나타나는 실험적 sigmoid 거동을 근사하게 재현할 수 있도록 모델 개선에 파편화 효과로 인한 반응 표면적 증대 및 결정립 가변 전환시간 개념을 고려하였다. UO2는 U3O7을 거쳐 U3O8으로 전환되며 최종 결정립 산화 소요 시간은 초기 결정립 산화 소요 시간의 10배에 해당한다는 가정을 도입했을 때, 개선된 모델은 599 - 674 K에서의 UO2 구 형 입자의 실험적 산화거동과 근사한 계산결과를 나타내었으며 핵종성장모델(Nucleation and Growth Model) 및 자촉매반응모델(AutoCatalytic Reaction Model)과 비교할 때 가장 작은 오차를 보여주었다. 개선된 모델을 통해 U3O8으로의 100% 전환시 계산된 활성화에너지값은 57.6 kJ·mol-1로 자촉매반응모델로 계산된 값인 48.6 kJ·mol-1보다 크며, 외삽에 의해 결정된 실험값에 더 근사함이 밝혀졌다.

본 연구에서는 가변 통기성 스마트 의류의 제작을 위해 필요한 형상기억합금 액추에이터의 작동 조건을 파악하였다. 의복의 개방, 폐쇄와 같은 양방향 작동 시 형태 변형 시에만 전력을 소모하는 저전력 소모 액추에이터 개발을 위해 복수 채널의 일방향 형상기억합금을 이용하여 스위치로 작동되는 액추에이터를 설계하였으며 가장 효율적으로 작동할 수 있는 와이어의 직경과 전압인가 단위시간을 도출하였다. 선행연구 결과 도출된 양방향 작동이 가능한 일방향 형상기억합금의 직경 범위 내에서 Arduino 스위치를 제작하여 3.7V 전압인가 시 변화량을 분석한 결과 0.4Φ의 액추에이터가 가장 적합한 것으로 나타났다. 0.4Φ 형상기억합금와이어를 사용한 양방향작동 액추에이터의 개방, 폐쇄에 필요한 최적전압인가 시간을 도출하기 위해 액추에이터의 최대개방, 최소폐쇄 도달 전압인가 시간으로부터 50ms씩 감소, 증가 시키며 냉각 후 액추에이터의 내경을 비교하는 방식으로 측정한 결과 개방 동작에 필요한 최적 전압인가 단위시간은 4,100ms로 나타났다. 각 채널간의 발열에 의한 간섭을 최소화하기 위한 양방향간 작동 시 필요 딜레이 분석을 위해 상온에서 형상기억합금에 최적 전압입가 시간인 4.1초 동안 전원을 공급하고 가열 후 냉각까지의 과정을 열화상카메라로 촬영하여 형상기억합금 와이의 온도가 냉각시의 상변태온 이하로 하강하는 시점을 파악한 결과, 액추에이터의 양방향간 작동 딜레이는 1.8초 이상이 확보되어야 함을 파악할 수 있었다.

PURPOSES:The objective of this study is to ascertain the curing period of cementless cold central plant recycled asphalt base-layer, using mechanical analyses and specimen quality tests on the field.METHODS :Cold central plant recycled asphalt base-layer mixture was produced in the plant from reclaimed asphalt, natural aggregate, filler for the cold mix, and the modified emulsion AP using asphalt mix design and plant mix design. In order to examine the applicability of the curing period during the field test, the international standards for the possibility of core extraction and the degree of compaction and LFWD deflection were analyzed. Moreover, Marshall stability test, porosity test, and indirect tensile strength test were performed on the specimens of asphalt mix and plant mix design.RESULTS :The plant production process and compaction method of cementless cold central plant recycled asphalt base-layer were established, and the applicability of the optical moisture content for producing the mixture was verified through the field test. In addition, it was determined that the core extraction method of the conventional international curing standard was insufficient to ensure performance, and the LFWD test demonstrated that the deflection converges after a two-day curing. However, the back-calculation analysis reveals that a three-day curing is satisfactory, resulting in a general level of performance of dense asphalt base-layer. Moreover, from the result of the specimen quality test of the asphalt mix design and plant mix design according to the curing period, it was determined that the qualities satisfied both domestic and international standards, after a two-day curing. However, it was determined that the strength and stiffness after three-day curing are higher than those after a two-day curing by approximately 3.5 % and 20 %, respectively.CONCLUSIONS:A three-day curing period is proposed for the cementless cold central plant recycled asphalt base-layer; this curing period can be demonstrated to retain the modulus of asphalt-base layer in the field and ensure stable quality characteristics.

This neurological damage accelerates the infection reaction of cells and apoptosis at the time of reperfusion after ischemia occurs. BCL-2/BCL-2 allogeneic begeminum has a function of suppressing the apoptosis of cells, and thus it is inferred that the susceptibility of cells to apoptosis is determined by the amount of allogeneic begeminum present which is determined based on the amount of BAX. Ischemia was induced in SD mice by occluding the common carotid artery for 5 minutes, after which blood was re-perfused. NEES was applied to acupuncture points, at 12, 24, and 48 hours post-ischemia on the joksamri, Hapgok. Protein expression was investigated through BAX antibody immuno-reactive cells in the cerebral nerve cells and Western blotting. The results were as follows: In the present study as well, as a result of observation of the change in the number of the BAX reaction cells after the inducement of GI, there was the aspect of most of the BAX reaction cells being observed in the corpus striatum area of the GI group 24 hours after the inducement of ischemia. This revealed the same results as those of previous studies in which the change in the number of BAX reaction cells occurred in all areas while ischemia was in progress. The change in the expression of BAX protein after 24 hours showed that there was a very significant reduction in the NEES group compared to the GI group (p<.01). As a result, a greatest amount of change in the number of BAX immunoreactive cells related to apoptosis 24 hours after ischemia appeared in the NEES group. This study that ischemia increases the expression of BAX that induces apoptosis. Thus, it is determined that ischemia is the main cause of the apoptosis of neurons, and this study reveals that low frequency needle electrode electrical stimulation has the effect of blocking the apoptosis of neurons by reducing protein related to the apoptosis of cells that has increased after ischemia has occurred.

This study explains an agricultural mobile commerce case using Oauth Based Real-Time Information Sharing Technique according to the growth of the agricultural e-commerce market. Considering the characteristics of the agricultural market, it can confirm differential values with the existing agricultural mobile commerce market according to the functions and characteristics of its technique. We compare variables for introducing agricultural mobile commerce with the existing mobile commerce. Trust through information sharing with real-timefarming diaries, suitability and perceived ease of use variables are positively influenced, but influence on completeness and authority of information variables are relatively insufficient. Through this, we explained differential values of agricultural mobile commerce and suggested an applicable business model.

This study introduces the methods to apply and develop the integrated Cost of Quality (COQ) and Time-Driven Activity-Based Costing (TDABC) model for seeking not only quality improvement but also reduction of overhead cost. Inefficient and uneconomical COQ activities can be identified by using time driver which also maximizes the quality improvement for Prevention-Appraisal- Failure (PAF) quality costs. In contrast, reduction of the indirect cost of unused capacity resource using Quality Cost Capacity Ratio (QCCR) of TDABC minimizes overhead cost for COQ activities. In addition, linkage between Overall Equipment Effective (OEE) and Time Driver develops the integrated system of Total Productive Maintenance (TPM) and TDABC model. Lean OEE maximizes when an Unused Time (UT) of TDABC that are TPM losses and lean wastes reduces whereas the TPM Cost Capacity Ratio (TCCR) of TDABC minimizes indirect cost for non-value added TPM activities. Numerical examples are derived to better understand the proposed COQ/TDABC model and TPM/TDABC model from this paper. From the proposed model, process mapping and time driver of TDABC are known to lessen indirect cost from general ledger of comprehensive income statement with a better quality innovation and improvement of equipment.

This study shows an application method of Micro Grid integrating Solar Energy Seasonal Storage (SESS) based on the analysis of time-variant load characteristics of electric railway. Micro Grid includes various renewable energy generation plants as like wind farm, photovoltaic, small hydro, fuel cell, etc. and some energy storage systems to meet the balance between generation production and demand. The essential concept of this paper is the connection and integration between electric railway and Micro Grid including SESS which is able to control power system frequency. This new concept for power system stabilization would be tested in an independent Micro Grid site and some detail application methods would be evaluated for the commercialization.

목적 : 지역사회에 거주하는 정신분열증 환자에게 시간관리 어플리케이션의 적용이 삶의 질에 미치는 영향을 분석하여 작업치료 중재의 임상적 효과를 검증하고자 한다. 연구방법 : 연구 참여자는 만 42세 여성 정신분열증 환자로 2011년 8월 1일부터 9월 23일까지 중재가 이루어졌다. 중재 과정은 처음 1주는 초기평가와 함께 생활시간조사를 분석하였으며, 활동 중에서 의미가 있는 활동과 의미가 없는 활 동으로 분류하였다. 의미가 없는 활동 대신에 생활시간에 본인이 수행하기를 원하는 활동으로 재배치하였다. 그 이후 1주는 어플리케이션 사용법에 대하여 교육하였으며, 중재는 3주간 이루어졌다. 중재가 끝나고 바로 재평가를 실시하 였으며, 추가로 2주 후에는 추적 연구가 이루어졌다. 결과 : S-QOL 점수는 초기 평가에서 45.36점이었으나 중재 후 재평가에서 66.34점으로 향상되었고, 추적 연구에서 60.98점으로 분석되어 중재 후 보다는 감소하였지만 중재 전보다는 증가하였다. 결론 : 시간관리 어플리케이션을 적용한 결과 대상자의 작업 균형이 향상되어 삶의 질이 높아졌다. 따라서 지역사회에 거 주하는 정신분열증 환자들에게 작업치료 중재방법으로 시간관리 어플리케이션이 고려되어야 할 것이다.