With the growth of the online market, demand for logistics and courier cargo is increasing rapidly. Accordingly, in the case of urban areas, road congestion and environmental problems due to cargo vehicles are mainly occurring. The joint courier logistics system, a plan to solve this problem, aims to establish an efficient logistics transportation system by utilizing one joint logistics delivery terminal by several logistics and delivery companies. However, several courier companies use different types of courier invoices. Such a system has a problem of information data transmission interruption. Therefore, the data processing process was systematically analyzed, a practically feasible methodology was devised, and delivery invoice information processing standards were established for this. In addition, the importance of this paper can be emphasized in terms of data processing in the logistics sector, which is expected to grow rapidly in the future. The results of this study can be used as basic data for the implementation of the logistics joint delivery terminal system in the future. And it can be used as a basis for securing the operational reliability of the joint courier logistics system.

Recently, various technologies for safety inspecting of electrical equipment such as energy storage system and contact line related with cu based conductor were studied. This paper were analysis quantitative evaluation technologies to determine the arc flash characteristics with abnormal state through the non-contact state. In particular, in order to analyze the characteristics of voltage, current and UV light according to arc flash, the test results of the arc flash simulator analyzed and presented. Various studies are being conducted on the characteristics of voltage, current, and arc light according to the occurrence of arc flash defects and it was analyzed that additional research need to can be used for defects detection in small-scale systems connected with storage devices such as ESS and electric railway systems and life expectancy systems.

This paper is on the suggestion of maintenance items for electric railway facility systems. With the recent increase in the use of electric locomotives, the utilization and importance of railroad electrical facility systems are also increasing, but the railroad electrical facility system in Korea is rapidly aging. To solve this problem, various methodologies are applied to ensure operational reliability and stability for railroad electrical facility systems, but there is a lack of detailed evaluation criteria for railroad electrical facility system maintenance. Also, maintenance items must be selected in a scientific and systematic method. Therefore, railroad electrical facility systems are selected for study. Design Structure Matrix (DSM) is utilized to establish considerations tailored to the maintenance characteristics, and the Fuzzy-TOPSIS methodology is utilized for determining the maintenance detail evaluation item baseline weights, a multi-criteria decision-making problem. Studies show that degradation, insulation items have the highest weight of 14.63%, and capacity items have the lowest weight of 5.34%. The results of this may be contributed to the underlying research in carrying out maintenance activities to ensure the reliability and safety of railroad electrical facility systems.

Despite various economic crisis situations around the world, the courier and delivery service market continues to be revitalized. The parcel shipping volume in Korea is currently 3.37 billion parcels, achieving a growth rate of about 140% compared to 2012, and 70% of parcels are from metropolitan areas. Given the above statistics, this paper focused on the development of an underground logistics system (ULS), in order to conduct a study to handle the freight volume in a more eco-friendly manner in the center of metropolitan areas. In this paper we first analyzed the points at which parcel boxes were damaged, based on a ULS. After collecting image data of the parcel boxes, the damaged parcel boxes were detected and classified using computerized methods, in particular, a convolutional neural network (CNN), MobileNet. For image classification, Google Colaboratory notebook was used and 4882 images were collected for the experiment. Based on the collected dataset, when conducting the experiment, the accuracy, recall, and specificity of classification for the testing set were 84.6%, 82% and 88.54%, respectively,. To validate the usefulness of the MobileNet algorithm, additional experiments were performed under the same conditions using other algorithms, VGG16 and ResNet50. The results show that MobileNet is superior to other image classification models when comparing test time. Thus, in the future, MobileNet has the potential to be used for identifying damaged boxes, and could be used to ensure the reliability and safety of parcel boxes based on a ULS.

Recently, as air pollution and particulate matter worsen, the importance of a platform that can monitor the air environment is emerging. Especially, among air pollutants, nitrogen dioxide (NO2) is a toxic gas that can not only generate secondary particulate matter, but can also derive numerous toxic gases. To detect such NO2 gas at low concentration, we fabricated a GNWs/NiO-WO3/GNWs heterostructure-based gas sensor using microwave plasma-enhanced chemical vapor deposition (MPECVD) and sputter, and we confirmed the NO2 detection characteristics between 10 and 50 ppm at room temperature. The morphology and carbon lattice characteristics of the sensing layer were investigated using field emission scanning electron microscopy (FESEM) and Raman spectroscopy. In the gas detection measurement, the resistance negative change according to the NO2 gas concentration was recorded. Moreover, it reacted even at low concentrations such as 5–7 ppm, and showed excellent recovery characteristics of more than 98%. Furthermore, it also showed a change in which the reactivity decreased with respect to humidity of 33% and 66%.

This paper analyzes the temperature rising characteristics of the deicing catenary system in winter. For the composition of the deicing system, the deicing system is constructed according to the combination of various trolley wires and messenger wires applied at Korea. To compare of temperature rising characteristics, the current distribution ratio between trolley wire and messenger wire are measured and the wire temperature is measured according to the deicing current using a catenary heating test device. In case of current distribution ratio test, the current distribution ratio is measured in 82.1%: 18.9% similar to the theoretical ratio in DC supplying. As a result of temperature rising test, the temperature of Cu 150 ㎟ is increased by 1.26 °C/m at a wind speed of 0.5 m/s and 0.92 °C/m at 2.0 m/s when supplying DC 350 A, And in case of Bz 65 ㎟, when DC 95 A is supplied, the temperature rose at 0.74° C/m at 0.5 m/s, and 0.56 °C/m at 2.0 m/s. In the comparison between the theoretical equation and test result, the difference is at most 0.7 ℃. Therefore, it is confirmed that it would be appropriate to use the theoretical equation in the design of the deicing system.

전기철도의 전차선로는 다양한 부품의 조합으로 이루어져 있으며 차량 팬터그래프와의 접촉과 전기 에너지 전달을 위해 일정 이상의 기계적, 전기적 특성을 유지하여야 하며 이를 위해 금속제품을 주조방식으로 제조하고 있다. 전차선로는 속도에 따라 부품의 치수와 성능이 다르며 유지보수나 리뉴얼에 따라 부품 단종 시에 소량의 제작에도 주물을 제작하여야 하며 일부 제품은 규격이 없어 소품종 생산에 적합한 기술이 필요하다. 본 논문은 3D 프린팅을 이용한 클레비스형 단말클램프와 회전형 클립 제작을 위해 기존의 2차원 도면을 3D 각각 3차원 모델링을 수행하였다. 제작후 기계적 특성 시험결과 인장강도와 내력은 532 N/㎟와 189 N/㎟로 KRSA의 기준값인 600 N/㎟과 250 N/㎟에 비해 낮은 특성을 나타내었다. 재료의 화학적 특성 분석 결과 Ni가 다소 낮게 나타났으나 본 논문에서 제안한 3차원 모델링 기반의 전철부품 제작 기술은 설계, 제작 및 시공을 연계하거나 부품 보강을 통한 전차선로 특성향상기술에 활용될 것으로 기대된다.

Recently, smart manufacturing technology research is being conducted in various fields, using digital parts-based technologies. Components that are used for electrification in electric railways are manufactured using casting techniques. This is because the mechanical and electrical properties required to ensure safety considerably vary, and the standards defined for errors are strict. To apply digital parts-based manufacturing technology to parts for electrification, the design of existing parts must be 3D-modelled, and research must be conducted on manufacturing techniques using metals. In this study, we investigated digital laminate manufacturing technology for smart manufacturing of parts for electrification. The clevis-type terminal clamp of the contact wire was manufactured using stereolithography apparatus. The deviation, which was measured using a 3D hybrid scanner and a 3D coordinate measuring device, was observed to be approximately ± 500 μm. The model illustrated in this paper will be used as a reference to study metal train parts in the future. In addition, it is expected to be used as a pre-modelling development technology for manufacturing singular-shaped parts.

Some of the Countries use DC 3kV for railroad electrification system. However, due to operational problems of electricity suppliers, unstable power is inevitable among some countries. For stable railroad operation, measures to solve the power shortage problem of electricity supplier are needed. Main purpose of this paper is to bring voltage stabilization under power shortage on DC railway system using Energy Storage System(ESS) and Renewable Energy Sources(RES). In order to supply the power shortage, 1MW Photovoltaic(PV) power plant is considered. By monitoring the catenary voltage, an algorithm capable of stabilizing the DC railroad voltage according to the voltage fluctuation of the power supplier is presented. Based on proposed algorithm, modeling was performed using the power system analysis program, PSCAD/EMTDC to verify. In addition, this paper makes various assumption of the voltage variations in order to check whether ESS and RES can stabilize the voltage.

We conducted experiments to improve the electrical properties of the CNW (carbon nanowall), which has lower electrical properties than other carbon allotropes such as graphene and CNT (carbon nanotube), and report the results through this article. The carbon nanowall has an amorphous buffer layer, leading to low electrical properties, and MWCNT (multi-walled carbon nanotube) was used as a buffer layer to improve this issue, and then a CNW was grown on it by CVD (chemical vapor deposition). Then, the content of MWCNT was adjusted to 30 µL, 50 µL, and 70 µL to analyze the electrical properties accordingly. Alteration in carrier concentration, carrier mobility and resistivity were observed as electrical properties. Dramatic changes in electrical properties with MWCNT content were identified. The ohmic contact state between the MWCNT-based buffer layer and the CNW was investigated by analysis of the I-V and I-R characteristics and the electrical stability according to the linearity of the curve.

외부 기온이 0℃ 이하로 내려가는 겨울철에는 전차선에 서리 및 결빙이 형성되고 이로 인한 차량 운행 시 아크 발생 등의 문제가 발생한다. 이러한 문제를 해결하기 위해 교류 급전계통의 경우에는 저항 열을 이용한 해빙시스템을 적용하고 있다. 본 논문에서는 직류 급전계통에서도 가공 전차선에 발생하는 서리 및 결빙을 제거하기 위한 해빙시스템을 구성하고 해빙시스템에 따른 해빙전류량을 예측하였다. 이를 위해 전원공급 변전소, 전차선 간을 연결하는 중간 변전소 그리고 폐루프를 구성하는 폐루프 변전소로 직류 급전계통 해빙시스템을 구성하였다. 그리고 계통 구성, 전압레벨 등을 고려하여 다양한 경우의 해빙시스템을 구성하고 해빙전류를 산출하였으며, 외부 환경 조건을 고려하여 해빙온도 상승을 예측하였다. 또한, 전력해석 프로그램을 이용한 시뮬레이션을 통해 여러 해빙시스템 구성에 따른 해빙전류 크기 비교를 통한 성능을 평가하였다. 이러한 해빙시스템 구성 및 해빙 시뮬레이션 모델을 활용함으로써 실제 운영 노선의 다양한 직류 급전계통에 대한 해빙시스템 구성에 활용할 수 있을 것으로 판단된다.

This paper presents an improved fault location estimation algorithm to reduce the fault location estimation error ratio in AT boosting current ratio technique. The domestic AC traction system uses the AT feeding system as a standard, and most of the lines are composed of double tracks(up and down lines). It was confirmed that the fault location estimation error is increased due to the change of the AT boosting current of the faulted line due to the other line’s AT boosting current characteristics. Therefore, in this paper, an improved fault location estimation algorithm is proposed by using all AT boosting currents considering of the other line’s boosting current characteristics. In order to evaluate the proposed algorithm performance, the AC railway power supply system is modeled and various fault simulations were performed using the power analysis program. As a result, when comparing the error of the existing technique and the improved technique, the improved algorithm shows an average error of 0.16%, and even the maximum error is 0.88%, which is satisfied within 2% of the domestic standard.

Currently, power conversion system which converts AC to DC Power is applied in domestic urban railway. The diode rectifier is used in most of them. However the diode rectifier can not control the output voltage and can not regenerate power as well. On the other hand, PWM (pulse width modulation) converter using IGBT (isolated gate bipolar transistor) can control output voltage, allowing it to reduce the output voltage drop. Moreover the Bi-directional conduction regenerates power which does not require additional device for power regeneration control. This paper compared the simulation results for the DC power supply system on both the diode rectifier and the PWM converter. Under the same load condition, simulation circuit for each power supply system was constructed with the PSIM (performance simulation and modeling tool) software. The load condition was set according to the resistance value of the currently operating impedance of light rail line, and the line impedance was set according to the distance of each substations. The train was set using a passive resistor. PI (proportional integral) controller was applied to regulate the output voltage. PSIM simulation was conducted to verify that the PWM Converter was more efficient than the diode rectifier in DC Traction power supply system.

경량전철시스템의 건설은 노선당 수천억 원에서 조 단위의 건설비가 소요되는 대형 복합인프라 사업으로, 건설된 시스템은 장기간 운영되기 때문에 생명주기관점에서 사업을 추진하는 것이 매우 중요하다. 시스템엔지니어링은 고객의 요구를 성공적으로 구현하는 수단 및 방법론으로 경량전철사업과 같은 대형 사업에 매우 유용하다. 이러한 시스템엔지니어링 접근법을 경량전철사업에 적용하기 위해 개발된 전산모델 SELRT(Systems Engineering application model for Light Rail Transit project)가 현장에서 활용되기 위해서는 모델에 대한 검증이 필요하다. 시스템엔지니어링에서의 검증은 시스템요구사항을 만족하였음을 확인하는 것이다. 따라서 본 논문에서는 시스템엔지니어링 방법론에 따라 검증 절차와 검증 아키텍처를 제시하고, 이에 따라 시스템요구사항을 식별하였다. 또한 시스템요구사항을 검증하기 위해 국제 표준규격 등 참조규격을 참고하여 검증요구사항 및 검증항목과 검증기준을 도출하였으며, 검증절차에 따라 SELRT를 시연하고 결과를 검증요구사항과 비교하였다. 그 결과 시스템요구사항과 검증요구사항의 추적성, 검증요구사항별 검증방법, 전산도구의 시연결과가 상호 연결되고, 최초요구사항이 SELRT에 명확히 구현되었음을 확인할 수 있어, 제안된 방법이 SELRT 검증에 유효하며, SELRT도 경량전철사업현장에서 활용될 수 있음이 확인되었다. The construction of a light rail transit (LRT) system is a large and complex infrastructure project involving hundreds of billions of won in construction costs for a single route, and it is very important to carry out such a project from a life-cycle perspective because of its long-term operation. Systems engineering is a means and methodology to successfully implement customers' needs, and it is useful in large projects such as light rail transit. An application model called Systems Engineering for Light Rail Transit (SELRT) was developed to support systems engineering activities in light rail transit projects. In order to utilize SELRT, it is necessary to ensure that system requirements are met. As such, in this paper, we present a verification procedure and architecture based on a systems engineering-based methodology, thereby identifying the system requirements and deriving the verification requirements to confirm the SELRT model for the proposed method. The results show that the traceability of the system requirements and verification requirements, the verification method for each requirement, and the demonstration results for computerized tools are mutually connected, and that the initial requirements are clearly implemented in the SELRT. The proposed method is valid for verifying the SELRT, which can also be utilized in a LRT project.

최근 철도 열차제어시스템은 최첨단 기술로 인한 무선통신기반 개발의 수요와 이에 따른 환경의 다변화로 인해 안전에 대한 쟁점도 증가하고 있다. 이에 따라 기존의 열차제어시스템에서 다루는 지상 설비 설계에 대한 단계별 안전 활동 강화의 필요성 역시 강조되고 있다. 국내 철도 산업은 대다수 열약한 산업환경으로 구성되어 있다. 이러다 보니, 설계 산출물에 대한 생성에 초점이 맞춰져 있지, 산출물에 대한 검증 방안 및 적용에 대한 역량이 상당히 부족한 실정이다. 따라서, 본 논문에서는 열차제어시스템 설계 단계의 아키텍처 산출물 검증 방안을 확보하기 위해 안전분석 산출물을 바탕으로 확보 가능한 방법에 대해 기술하고 있다. 이렇듯 설계적 산출물에 대한 검증방안을 구축하고 직접 수행에 따른 설계적 무결성을 높이고자 한다. 특히, FMEA 안전 분석 기법을 활용해, 안전 분석 기법을 통해 개별 단계별 산출물의 활용을 통한 아키텍처 산출물과의 연계성 확보를 통해 무결성 확보를 위한 기술적 접근법을 기술하였다. 본 연구의 결과를 토대로 안전성 향상 접근에 대한 시험 활동 재정립을 통해 개선함으로써 향후 모델 기반 열차제어시스템 개발 시 개념설계에서 발생할 수 있는 안전성 이슈를 제거 함에 따라, 설계적 비용 및 시간을 절감 및 안전성 향상을 기대할 수 있을 것으로 기대된다. Safety is the most important factor for train control systems. Model-based design and safety activities for way-side equipment in train control systems are important factors. Model-based architecture verification was carried out to develop an effective control system, which is represented by model-based failure mode and effects analysis (FMEA). An architecture verification method was created based on FMEA to take advantage of a design model and improve the train safety control system. Case studies were applied to architecture verification scenarios, and the results demonstrate the usability of the method. The improved method is expected to reduce the cost and time in the conceptual design for future development of model-based verification train control systems.