• 한국항만경제학회지
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• 제39권1호
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• pp.47-63
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• 2023

스마트 항만 및 항만 자동화에 수직 배치형 컨테이너 터미널을 적용하여 운영하는 사례가 늘고 있다. 본 연구는 수평 배치형과 수직 배치형 컨테이너 터미널에서의 본선작업 시간을 분석함으로써 각 터미널간 생산성을 비교하고, 향후 수직 배치형 컨테이너 터미널의 운영 효율성 증대 방안을 제시하고자 한다. 이를 위해 각각을 대표하는 터미널을 선정하여, 2018년부터 2022년까지 최근 5년 선석배정현황 데이터를 수집하였으며, 모수적 생존분석 기법인 가속실패시간모형(Accelerated Failure Time, AFT)을 활용하여 분석을 실시하였다. C/C 작업 조건이 '동일하다'는 가정 하에서, 수직 배치형 컨테이너 터미널에서의 본선 작업 생산성이 보다 좋은 것으로 나타났으며, 코로나19 기간에는 생산성이 감소한 결과를 나타냈다. 작업량이 많은 선박의 경우와 유럽 선사의 선박의 경우, 본선작업 시간이 감소하는 걸 알 수 있다. 적정 C/C의 투입 및 효율적 운영, 장비들 간 원활한 운영, shifting 작업은 증가, C/C를 포함한 하역 장비들의 준비시간 감소 및 고장/사고 최소화 등 수직 형태 컨테이너 터미널의 생산성을 높이기 위한 방안을 제시하였다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 춘계학술대회
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• pp.542-545
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• 2022

최근 중대재해의 처벌관련법이 건설 환경에 대한 관심을 끌고 있다. 공사현장의 안전관리를 점검하는 일반적인 방법은 근무자가 직접 그들의 눈으로 현장을 확인하는 것이다. 하지만 이 방식은 근무자의 능력의 한계에 영향을 받을 수밖에 없고, 그 결과 피로와 작업 능률 저하를 일으키게 된다. 이런 이유로, 이는 효율적인 방법이 될 수 없다. 이에 우리는 본 연구를 통해 상기 방법을 보완할 수 있는 효율적인 ICT 안전관리 시스템을 제안하여, 작업환경 및 공사 현장 안전에 도움 주고자 한다. 본 논문은 RFID를 활용한 출입 관리 시스템 설계와 소음 센서 및 미세 먼지 센서를 통한 현장 정보 모니터링 방식을 설명한다. 또한, PIR 센서로 중장비와 사람 간의 사고를 예방하고, 자이로 센서를 통해 작업 중인 건물의 기울기를 파악하여 안전사고를 예방할 수 있는 시스템을 제안한다.

• 농촌계획
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• 제28권4호
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• pp.41-53
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• 2022

This study aims to identify perceptions on ESG management evaluation priorities based on public value in the agricultural and rural sector with the focus on the Korea Rural Community Corporation. We conduct Analytic Hierarchy Process (AHP) to analyze how ESG management evaluation priorities are perceived by distinctive groups across industrial fields. To this end, experts working in the agricultural and rural sector and the general public in non-agricultural sector were questioned to derive and compare the weights for each class of ESG management. Results show the followings: First, the weight for the environment (E) was derived as 0.51774 in the first layer, which was found to be the most important evaluation item among the environment (E), society (S), and governance (G). Second, "ecosystem restoration," "urban-rural exchange expansion and regional development," and "increasing transparency" were the most important items in the second layer. Third, priorities between the agricultural and non-agricultural respondents groups were different in environmental (E) and social (S) categories, which explained that perceptions on ESG management by workers and policy makers in the agricultural and rural sector are different from those by general public in the non-agricultural sector.

• 드라이브 ㆍ 컨트롤
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• 제20권2호
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• pp.31-39
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• 2023

The aim of this study was to measure and analyze engine load factor (LF) according to working conditions (operation type and gear stage) of small agricultural multi-purpose cultivator to estimate the emission of air pollutants. To calculate LF, a torque sensor capable of collecting torque and rotational speed was installed on the engine output shaft and DAQ was used to collect data. A field test was conducted with major operation of a cultivator and tillage operations (plow tillage and rotary tillage). Engine power was calculated using engine torque and rotational speed and LF was calculated using real-time power and rated power. In addition, unified LF was calculated using the weight for each operation and the average LF for each operation. As a result, average LF values at 1.87 and 3.10 km/h by plow tillage were 0.50 and 0.69, respectively. Average LF values at 1.87 and 3.10 km/h by rotary tillage were 0.70 and 0.78, respectively. Furthermore, unified LF calculated in consideration of the weight factor showed a value of 0.65, which was 135% higher than the conventional LF (0.48). Results of this study could be used as basic information for realizing LF values in the field of agricultural machinery.

• Smart Structures and Systems
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• 제30권5호
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• pp.479-500
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• 2022

In this study, a new type of isolation bearing is proposed by combining S-shaped steel plate dampers (SSDs) with a spherical steel bearing, and the seismic control effect of a five-span standard high-speed railway bridge is investigated. The advantages of the proposed S-shaped steel damping friction bearing (SSDFB) are that it cannot only lengthen the structural periods, dissipate the seismic energy, but also prevent bridge unseating due to the restraint effectiveness of SSDs in the large relative displacements between the girders and piers. This study first presents a detailed description and working principle of the SSDFB. Then, mechanical modeling of the SSDFB was derived to fundamentally define its cyclic behavior and obtain key mechanical parameters. The numerical model of the SSDFB's critical component SSD was verified by comparing it with the experimental results. After that, parameter studies of the dimensions and number of SSDs, the friction coefficient, and the gap length of the SSDFBs were conducted. Finally, the longitudinal seismic responses of the bridge with SSDFBs were compared with the bridge with spherical bearing and spherical bearing with strengthened shear keys. The results showed that the SSDFB can not only significantly mitigate the shear force responses and residual displacement in bridge substructures but also can effectively reduce girder displacement and prevent bridge unseating, at a cost of inelastic deformation of the SSDs, which is easy to replace. In conclusion, the SSDFB is expected to be a cost-effective option with both multi-stage energy dissipation and restraint capacity, making it particularly suitable for seismic isolation application to high-speed railway bridges.

• Smart Structures and Systems
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• 제32권3호
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• pp.135-151
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• 2023

Using 3D asphalt pavement surface data, a deep and multiscale network named CrackNet-M is proposed in this paper for pixel-level crack detection for improvements in both accuracy and robustness. The CrackNet-M consists of four function-specific architectural modules: a central branch net (CBN), a crack map enhancement (CME) module, three pooling feature pyramids (PFP), and an output layer. The CBN maintains crack boundaries using no pooling reductions throughout all convolutional layers. The CME applies a pooling layer to enhance potential thin cracks for better continuity, consuming no data loss and attenuation when working jointly with CBN. The PFP modules implement direct down-sampling and pyramidal up-sampling with multiscale contexts specifically for the detection of thick cracks and exclusion of non-crack patterns. Finally, the output layer is optimized with a skip layer supervision technique proposed to further improve the network performance. Compared with traditional supervisions, the skip layer supervision brings about not only significant performance gains with respect to both accuracy and robustness but a faster convergence rate. CrackNet-M was trained on a total of 2,500 pixel-wise annotated 3D pavement images and finely scaled with another 200 images with full considerations on accuracy and efficiency. CrackNet-M can potentially achieve crack detection in real-time with a processing speed of 40 ms/image. The experimental results on 500 testing images demonstrate that CrackNet-M can effectively detect both thick and thin cracks from various pavement surfaces with a high level of Precision (94.28%), Recall (93.89%), and F-measure (94.04%). In addition, the proposed CrackNet-M compares favorably to other well-developed networks with respect to the detection of thin cracks as well as the removal of shoulder drop-offs.

• 드라이브 ㆍ 컨트롤
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• 제20권4호
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• pp.71-79
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• 2023

In the field of agricultural machinery, various on-field tests are conducted to measure design load for optimal design of agricultural equipment. However, field test procedures are costly and time-consuming, and there are many constraints on field soil conditions due to weather, so research on utilizing simulation to overcome these shortcomings is needed. Therefore, this study aimed to model agricultural soils using discrete element method (DEM) software. To simulate draft force, predictions are made according to travel speed and compared to field test results to validate the prediction accuracy. The measured soil properties are used for DEM modeling. In this study, the soil property measurement procedure was designed to measure the physical and mechanical properties. DEM soil model calibration was performed using a virtual vane shear test instead of the repose angle test. The DEM simulation results showed that the prediction accuracy of the draft force was within 4.8% (2.16~6.71%) when compared to the draft force measured by the field test. In addition, it was confirmed that the result was up to 72.51% more accurate than those obtained through theoretical methods for predicting draft force. This study provides useful information for the DEM soil modeling process that considers the working speed from the perspective of agricultural machinery research and it is expected to be utilized in agricultural machinery design research.

• Smart Structures and Systems
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• 제33권1호
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• pp.1-16
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• 2024

The investigation on vehicle-bridge coupling system (VBCS) is crucial in bridge design, bridge condition evaluation, and vehicle overload control. A real-time hybrid testing (RTHT) method for VBCS (RTHT-VBCS) is proposed in this paper for accurately and economically disclosing the dynamic performance of VBCSs. In the proposed method, one of the carriages is chosen as the experimental substructure loaded by servo-hydraulic actuator loading system in the laboratory, and the remaining carriages as well as the bridge structure are chosen as the numerical substructure numerically simulated in one computer. The numerical substructure and the experimental substructure are synchronized at their coupling points in terms of force equilibrium and deformation compatibility. Compared to the traditional iteration experimental method and the numerical simulation method, the proposed RTHT-VBCS method could not only obtain the dynamic response of VBCS, but also economically analyze various working conditions. Firstly, the theory of RTHT-VBCS is proposed. Secondly, numerical models of VBCS for RTHT method are presented. Finally, the feasibility and accuracy of the RTHT-VBCS are preliminarily validated by real-time hybrid simulations (RTHSs). It is shown that, the proposed RTHT-VBCS is feasible and shows great advantages over the traditional methods, and the proposed models can effectively represent the VBCS for RTHT method in terms of the force equilibrium and deformation compatibility at the coupling point. It is shown that the results of the single-degree-of-freedom model and the train vehicle model are match well with the referenced results. The RTHS results preliminarily prove the effectiveness and accuracy of the proposed RTHT-VBCS.

• 경영정보학연구
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• 제18권3호
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• pp.137-153
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• 2016

조직의 비즈니스 환경이 스마트워크와 같이 모바일이나 네트워크에 의존하는 비중이 높아지면서, 기업들은 정보보안에 더 높은 관심을 가지게 되었다. 특히, 내부자의 의한 정보유출은 기업입장에서 상당히 부정적인 영향을 미치게 된다. 따라서 기업뿐 아니라 정보보안 관련 연구자들은 조직원의 정보보안 정책 준수에 초점을 두어 연구를 해왔다. 그 중에서 정보보안 대책(Information security countermeasure)은 조직원의 정보보안 정책 준수 의도의 선행요인으로 알려져 왔다. 하지만 조직원이 정보보안 대책을 인식하도록 하는 선행요인에 대한 연구는 미흡한 실정이다. 본 연구는 조직원의 보안대책 인식에 대한 선행요인으로 경영진의 정보보안 지능을 제안하고 이들의 관계를 실증적으로 연구하였다. 정보보안 지능은 Kirwan(2008)이 제안한 안전지능을 응용하여 정보보안 관련 문제해결능력, 사회적 역량, 정보보안 지식으로 구성된다. 연구결과 경영진의 정보보안 관련 문제해결 능력과 정보보안 지식은 조직원이 정보보안 정책 및 교육/훈련 프로그램을 인식하는데 긍정적인 영향을 미치는 것으로 나타났다.

• 한국컴퓨터정보학회논문지
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• 제29권5호
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• pp.67-74
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• 2024

최근 커피전문점이 급격히 늘어남과 동시에 커피 전문점에서 공부나 작업을 하는 사람들이 많이 나타나게 되었으며, 커피전문점에서는 고객 회전율, 수익 등에 문제로 고객들의 매장 이용에 관한 분석이 요구되기 시작하였다. 이러한 분석을 위해 영상 분석, QR 코드 인증, 블루투스 비콘 등의 방법들이 제안되었으나, 사생활 침해 문제, 낮은 정확성 등의 문제점이 있어 활용이 쉽지 않다. 따라서 본 연구에서는 이 문제점을 해결하며, 보다 정확한 매장 내 혼잡도 정보를 제공하기 위해 고주파 신호 기반 혼잡도 측정 시스템을 제안한다. 고주파 신호는 블루투스 신호를 대치하며, 신호의 전달 범위가 매장 내로 한정되어 정확도를 높일 수 있는 장점이 있다. 제안 시스템의 성능 검증을 위해 블루투스 기반 혼잡도 측정과 비교 실험을 진행하였고, 그 결과 제안 방법이 보다 높은 정확도를 나타내었다. 즉, 제안 방법은 커피 전문점에서의 혼잡도 정보 제공 및 통계처리에 효과적인 유용한 서비스가 될 것이다.