본 연구에서는 동명대학교 조선해양시뮬레이션센터의 Real-time 조종 및 작업 시뮬레이터를 활용한 해양구조물 설치 작업 시뮬 레이션을 통해 대상의 동적 특성 및 물리적 현상을 작업, 조종 사이의 상호 영향과 함께 분석한다. 8개의 계류삭에 의해 계류되는 반잠수 식 시추선의 설치 작업 시뮬레이션이 실제 현장에서의 작업과 유사한 시나리오로 수행되었고, 시추선의 위치 제어를 위한 예인선 4척와 계류삭의 Hook-up 작업을 위한 해양플랜트 지원 선박 1척이 운용되었다. 설치 작업이 수행되는 동안 대상들의 운동과 이동 경로, 계류삭 및 예인줄에 가해지는 장력 등을 실시간으로 확인하였으며, 이를 작업 과정별로 구분하여 분석하였다. 작업과 조종 시뮬레이션이 동시에 수행된 본 연구로부터 특정 환경 외력하에서 설치되는 해양구조물과 이를 위해 운용되는 선박들의 작업 절차에 따른 세부적인 거동 및 작업·조종 간의 상호 영향을 확인하였고, 이는 해상 상태 등을 고려한 해양구조물 설치 작업의 수행 가능 여부를 판단하기 위한 근거로 활용될 수 있음을 제시하였다.

현재의 해양산업의 기술은 스마트 선박 및 자율운항선박 등의 개발과 같은 자율화 및 지능화와 환경규제의 강화에 맞추어 선 박의 운항 효율성을 개선하는 친환경 선박을 위한 기술이 함께 개발되고 있다. 이러한 흐름에 맞추어, 세계각국에서는 선박의 안전운항을 보장하는 선에서 선박운항효율을 극대화하기 위해 다양한 방식으로 노력하고 있다. 본 연구에서는, 현존하는 선박운항효율 개선 기술이 운항 당시의 기상환경, 선박조종 등의 선박운항상태를 실시간으로 반영하지 못하는 문제를 개선하기 위해, 선박에서 수집한 선박운항데 이터를 활용하여 실시간 선박운항효율 분석모델을 개발하고자 한다. 본 연구의 실시간 선박운항효율 분석모델은 연료소모를 기준으로 판 단한 선박운항효율과 당시의 선박운항상태를 감안하여 판단한 선박운항효율을 비교하여, 식별된 선박운항효율의 타당성을 확인할 수 있 는 모델이다. 분석의 주요 내용은 대상선박의 선정과 선박운항데이터의 수집, 선박운항효율 특성과 선박운항상태 특성의 구분, 그리고 이 를 활용한 분류모델의 개발을 포함한다. 연구의 결과는 기존의 선박운항효율과 항해 당시 선박운항상태를 감안한 운항효율을 제시하여 선박 운항자의 의사결정을 지원하여 운항효율을 개선하고자 한다.

PURPOSES : The initial smoothness of concrete pavement surfaces must be secured to ensure better driving performance and user comfort. The roughness was measured after hardening the concrete pavement in Korea. When the initial roughness is poor, relatively large-scale repair works, such as milling or reconstruction must be performed. Hence, a method to measure the roughness of the concrete pavements in realtime during construction and immediately correct the abnormal roughness was developed in this study. METHODS : The profile of a concrete pavement section was measured at a construction site using sensors that were attached to the tinning equipment of the paver. The measured data included outliers and noise caused by the sensor and vibration of the paving equipment, respectively, which were further calibrated. Consequently, the calibrated data were input into the ProVAL program to calculate the roughness based on the international roughness index (IRI). Additionally, the profile of the section was re-measured using another method to verify the reliability of the calculated IRI. RESULTS : The profile data measured at the concrete pavement construction site were calibrated using methods, such as overlapped boxplot outlier removal and low-pass filtering. The outlier data from the global positioning system (GPS), which was installed to identify the construction distance, was also calibrated. The IRI was calculated using the ProVAL program by matching the measured profile and GPS data, and applying the moving average method. The calculated IRI was compared to that measured using another method, and the difference was within the tolerance. CONCLUSIONS : A method to measure the roughness of the concrete pavements in real time during construction was developed in this study. Hence, the performance of concrete pavements can be improved by enhancing the roughness of the pavement considerably using the aforementioned method.

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.

Different materials have been shown to "catalyze" carbon nanotube (CNT) growth in chemical vapor deposition (CVD) when they become nano-sized particles. Catalysts, which act as a kind of "seed" for CNT growth, show two types of behavior in the CVD method; precipitation of carbon atoms from the eutectic alloy forming a kind of alloy with carbon; the fact that the catalyst remains as a solid phase and forms a carbon surface layer during the CVD process. This study examines the relationship between the iron-group and non-iron-group catalyst types and the catalyst concentration and growth time of CVD-based CNT growth via emphasizing growth mechanisms. The novelty of this work is to compare and evaluate the effects of catalyst type, concentration, and growth time, which are three critical CVD parameters, on the final nanotube morphology. It was utilized five different catalysts ( Fe2O3, Fe3O4, Nb2O5, Au, and Pt), three different growth durations (3, 5, and 7 min), and three different catalyst concentrations (2, 4, and 6 wt%) to explore the morphological differences on CNT synthesis by CVD under the same process parameters. The results demonstrated that catalyst type is the most influential parameter in CVD-based CNT synthesis, while catalyst concentration and growth time are indispensable elements for the uniformity and small diameter in the final morphology.

In the case of a die-casting process, defects that are difficult to confirm by visual inspection, such as shrinkage bubbles, may occur due to an error in maintaining a vacuum state. Since these casting defects are discovered during post-processing operations such as heat treatment or finishing work, they cannot be taken in advance at the casting time, which can cause a large number of defects. In this study, we propose an approach that can predict the occurrence of casting defects by defect type using machine learning technology based on casting parameter data collected from equipment in the die casting process in real time. Die-casting parameter data can basically be collected through the casting equipment controller. In order to perform classification analysis for predicting defects by defect type, labeling of casting parameters must be performed. In this study, first, the defective data set is separated by performing the primary clustering based on the total defect rate obtained during the post-processing. Second, the secondary cluster analysis is performed using the defect rate by type for the separated defect data set, and the labeling task is performed by defect type using the cluster analysis result. Finally, a classification learning model is created by collecting the entire labeled data set, and a real-time monitoring system for defect prediction using LabView and Python was implemented. When a defect is predicted, notification is performed so that the operator can cope with it, such as displaying on the monitoring screen and alarm notification.

타임루프는 등장 인물에게 반복되는 시간의 주기를 경험하게 하는 장치로, 주기적 시간에서의 반복적 실패 를 통해서 문제를 파악하고 해결하는 과정이 드러나 있는 것이 특징이다. 본 논문에서는 타임루프 장치를 통한 반복이 게임의 전개와 플레이어의 경험에 어떤 작용을 하는지 알아보기 위해 게임 ‘12 Minutes’을 중심 으로 게임요소와 스토리텔링을 살펴보았다. 이를 위해 게임에서 타임루프로 인지되는 인터랙션이 무엇이고, 그 안에서 플레이어 캐릭터와 플레이어의 위치, 게임의 목표와 분기점이 어떻게 변화하는지 분석하였다. 그 결과, 다음과 같은 사실을 알게 되었다. 첫째, 타임루핑 게임에서 반복적 인터랙션은 오브젝트와 플레이어, 캐릭터 사이에 일어나는데, 루핑을 알고 있는 존재는 플레이어 캐릭터와 플레이어로 타임루핑은 플레이어 차원과 플레이어 캐릭터 차원에서 일어난다는 점이다. 둘째, 게임에서 타임루프는 다중의 서사를 만들어내 는 플랫폼으로 문제해결을 위한 다양한 시도가 가능하고, 플레이어가 가상 세계에 행하는 행위를 통해 자신 의 욕망하는 바를 잘 드러낼 수 있도록 기능하는 장치라는 것이다.

본 논문은 미술가 정규(鄭圭, 1923-1971)의 미술비평에 나타난 시대의식을 통해 그가 구 상한 전후 새로운 한국 현대미술을 분석하여 규명하는 데 목적을 둔다. 창작 활동 이외에도 비평, 교육, 행정 등 미술의 다방면에서 활약한 그의 예술관 중심에는 전전(戰前)에 대한 종합적 반성을 토대로 전후(戰後)라는 새 시대에 적합한 한국 현대미술의 모색이 있었다. 전후 한국미술계는 거 대한 흐름을 형성한 한국 앵포르멜을 중심으로 실존주의의 불안과 부조리를 내적으로 탐구했다. 반면 정규는 실존주의의 휴머니즘에 주목하여 극복의 징후로 이해한 뒤 동시대 한국의 현실에 반응 한 미술을 모색하고자 했다. 이러한 지점은 그가 회화를 중심으로 재편되어가던 한국미술계에서 낮은 장르로 취급되던 판화, 도예 등 독자적인 활동을 펼치게 추동했다. 본 연구는 초기 한국 현대 미술이 형성되어 가는 과정을 다각도로 이해하기 위하여 전후 시기 새로운 차원의 미술을 시도한 정규를 주목하면서 시작됐다. 이에 전후 시기 주요 논객으로 활동했던 그의 저술을 분석하여 그가 궁극적으로 정립하고자 했던 한국 현대미술을 체계화하고자 했다. 이를 통해 한국 현대미술의 형성 기인 전후 시기 미술에 관해 보다 입체적으로 해석할 가능성을 제안할 수 있을 것으로 기대한다.

PURPOSES : Recently, increasing number of local governments are introducing on-demand public transportation service in real time to improve the management efficiency of public transportation. In preparation for the autonomous driving era, the “autonomous public transportation mobility on-demand service in real time” is being developed in the public transportation sector to introduce on-demand public transportation. For this service to become the public transportation of the future, it must receive publicity. Therefore, in this study, indicators were selected to evaluate the publicity of the autonomous public transportation mobility on-demand service in real time, and a survey was conducted among the general public to examine the validity of the indicators. METHODS : To secure the publicity of on-demand public transportation in real time, the goal of the service was first set. Second, the keywords of the service were analyzed to define the publicity requirements of this service. Based on the analyzed keywords and definition of publicity, service indicator types were classified, and the indicators were defined by type. A user satisfaction survey was conducted on the final selected indicators to improve the degree of completion of indicator development. The user survey was conducted by presenting selected publicity indicators to respondents responding on a five-point scale to determine whether each indicator could satisfactorily evaluate publicity. RESULTS : When examining various previous research cases and the contents required for autonomous public transportation mobility on-demand service in real time, the required items of publicity indicators were found to be “safety” in terms of “autonomous driving” and “convenience” in terms of “demand response.” Publicity indicators were developed according to these three items. Thirty-one indicators were developed, and a satisfaction survey was conducted on the general public for each indicator. In the survey, most of the indicators scored 3.5 points or higher, indicating that the indicators were generally well defined. Users gave the highest score to “fairness” among the three items, and “reasonable fairness” was found to be a necessary item as a publicity indicator. CONCLUSIONS : In this study, evaluation indicators were selected to secure the publicity of autonomous public transportation mobility on-demand service in real time, and a satisfaction survey was conducted for each indicator. Most of the indicators showed a score of 3.5 or higher, indicating that they were generally well defined. However, this study has a limitation in that it surveys the general population. In future, experts should be included in the survey to increase the degree of completeness of the public indicators.

PURPOSES : The objective of this study is to analyze the significance of binder aging in a hot-mix asphalt (HMA) mixture in an insulated camber for a long duration for repair works, where the absolute viscosity level and service life reduction (SLR) are assessed based on the haul time, as well as to suggest a methodology for reducing the aging level. METHODS : Because the HMA mixture is stored in an insulated box carriage at high temperature for repair works, if the binder in the mix is severely oxidized, then the repaired pavement will not exhibit a long service life. Therefore, the 13-mm dense-graded HMA mix with PG64-22 was aged in an oven at 160 °C for 1, 2, 4 and 8 h to evaluate its aging level. Gel-permeation chromatography was performed on the mixture particle without binder recovery to measure the large-molecular size ratio, from which the estimated absolute viscosity (EAV) was computed using a best-fit regression model. The SLR values of aged and repaired mixes were estimated to determine the amount of deterioration in the mixes caused by severe aging. Hydrated lime (HL) was introduced into the mix at a ratio of 1.5 wt% of the total mix. The aging level and SLR were compared with those of the repaired mix without HL. RESULTS : The binder EAV of the HMA mix increases significantly with the mixture aging duration. In particular, the binder EAV level of a 4-h aged mix is similar to the asphalt viscosity level of a pavement with approximately 7 years of service life. The service life expressed based on the aging level is interpreted as the reduced service life of the aged mix, which is already oxidized before it is used. Meanwhile, the binder of an 8-h aged mix without HL aged significantly and its SLR is approximately 11 years. However, its aging level and SLR reduced significantly when HL. is incorporated. CONCLUSIONS : The binder aging level of the repaired mix increases significantly with its storage duration in a hot chamber for carriage. However, since the aging level decreases significantly by the incorporation of HL, the use of HL is highly recommended when preparing new mix for repair works to be performed in a hot-chamber for a long duration.

시설재배지 고추를 가해하는 꽃노랑총채벌레(Frankliniella occidentalis)를 대상으로 미끌애꽃노린재(Orius laevigatus)를 이용한 생물적 방 제가 검토되고 있다. 그러나 대상 해충의 빠른 집단 성장은 화학 살충제의 투입이 때에 따라 요구된다. 본 연구는 화학 살충제와 천적의 이상적 종합 방제를 구현하기 위한 목적으로 선택성이 높은 살충제 선발 및 이들 살충제 처리 이후 미끌애꽃노린재의 안전한 재투입 시기를 결정하기 위해 수행 되었다. 첫째로 꽃노랑총채벌레에 방제 효과가 높은 상용 살충제가 선발되었다. 총 17종류의 상용 살충제 가운데 5종류(pyriproxyfen+ spinetoram, abamectin, spinosad, acetamiprid, chlorpyrifos) 주성분을 갖는 상용 살충제가 꽃노랑총채벌레에 우수한 방제효과를 주는 약제로 선발되었다. 이들 5종류의 살충제에 대해서 미끌애꽃노린재의 감수성 반응은 꽃노랑총채벌레와 상이하였다. 특별히 아바멕틴과 스피네토람이 유 기인계 또는 네오니코티노이드에 비해 상대적으로 낮은 독성을 보였다. 이들 5종류의 살충제 처리 이후 잔류 독성을 미끌애꽃노린재를 이용하여 생물검정한 결과 유기인계 및 네오니코티노이드 약제는 비교적 오랜 기간 독성을 유지하지만, 아바멕틴과 스피네토람 약제의 경우 3일 이후에는 대상 천적에 피해를 주지 않는 것으로 나타났다. 이러한 잔류독성결과는 LC-MS/MS를 이용한 농약 잔류량 화학분석을 통해 뒷받침되었다. 이상 의 결과는 높은 밀도로 증가한 꽃노랑총채벌레에 대해서 이 해충에 살충성이 높은 아바멕틴 또는 스피네토람의 약제를 살포하고 이후 3일 지나 미 끌애꽃노린재의 투입을 통해 대상 해충의 평균 밀도를 경제적피해수준 이하로 유지할 수 있다는 종합방제 기술을 제시하고 있다.

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.

This study aimed to evaluate the germination characteristics, -glucan and antioxidant contents, and antioxidant activity of naked oat according to germination temperature (20, 25, and 30oC) and time (24, 48, and 72 h). Sprout length was highest at 25oC, and the rotten degree was increased as the germination temperature and time increased. The -glucan content of naked oat increased after 24 h of germination at all temperatures and then decreased by 72 h of germination. Total polyphenol content, flavonoid content, and antioxidant activity increased as the germination temperature and time increased.

Anomaly detection for each industrial machine is recognized as one of the essential techniques for machine condition monitoring and preventive maintenance. Anomaly detection of industrial machinery relies on various diagonal data from equipped sensors, such as temperature, pressure, electric current, vibration, and sound, to name a few. Among these data, sound data are easy to collect in the factory due to the relatively low installation cost of microphones to existing facilities. We develop a real time anomalous sound detection (ASD) system with the use of Autoencoder (AE) models in the industrial environments. The proposed processing pipeline makes use of the audio features extracted from the streaming audio signal captured by a single-channel microphone. The pipeline trains AE model by the collected normal sound. In real factory applications, the reconstruction error generated by the trained AE model with new input sound streaming is calculated to measure the degree of abnormality of the sound event. The sound is identified as anomalous if the reconstruction error exceeds the preset threshold. In our experiment on the CNC milling machining, the proposed system shows 0.9877 area under curve (AUC) score.

The purpose of this study was to investigate the Maillard reaction–related physicochemical properties of three maize varieties (Kwangpyeongok, Sinhwangok2ho and Gangdaok) after roasting them for different times (0, 15, 25, 40, and 55 minutes). The Maillard reaction is a non-enzymatic browning reaction involving reducing sugars and amino compounds. The content of reducing sugar, the causative agent of the Maillard reaction, decreased as roasting time increased. Gangdaok showed the lowest reducing sugar content of 1.04 mg/g after 55 minutes of roasting. In the elapsed roasting time, chromaticity ‘L’ and ‘b’ values decreased. At 55 minutes of roasting, wherein the Maillard reaction occurred most actively, Gangdaok showed the lowest ‘L’ value of 56.37 and the highest ‘a’ value of 7.60. Gangdaok had superior conditions for inducing the Maillard reaction compared to other varieties, and it is consider that 'flint–type', an endosperm characteristic, may have been the influencing agent. This study detected a total of 52 types of volatile aroma compounds (VACs), of which 28 were produced after roasting. Of the total VACs detected, 2-Formyl-5-methylfuran and 2-Furancarboxaldehyde accounted for 43.8~45.5% and have been confirmed to be the major VACs present in roasted maize. Most of the correlations between the Maillard reaction–related characteristics showed high correlation coefficients.