• Journal of KIISE
• /
• v.44 no.2
• /
• pp.213-222
• /
• 2017

The Internet of Things (IoT) technology is rapidly developing in recent years, and is applicable to various fields. A smart factory is one wherein all the components are organically connected to each other via a WSN, using an intelligent operating system and the IoT. A smart factory technology is used for flexible process automation and custom manufacturing, and hence needs adaptive network management for frequent network fluctuations. Moreover, ensuring the timeliness of the data collected through sensor nodes is crucial. In order to ensure network timeliness, the power consumption for information exchange increases. In this paper, we propose an IEEE 802.15.4e DSME-based distributed scheduling algorithm for mobility support, and we evaluate various performance metrics. The proposed algorithm adaptively assigns communication slots by analyzing the network traffic of each node, and improves the network reliability and timeliness. The experimental results indicate that the throughput of the DSME MAC protocol is better than the IEEE 802.15.4e TSCH and the legacy slotted CSMA/CA in large networks with more than 30 nodes. Also, the proposed algorithm improves the throughput by 15%, higher than other MACs including the original DSME. Experimentally, we confirm that the algorithm reduces power consumption by improving the availability of communication slots. The proposed algorithm improves the power consumption by 40%, higher than other MACs.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.13 no.6
• /
• pp.1411-1416
• /
• 2018

Currently, most of the industrial areas like chemistry, manufacturing, shipbuilding, and steel, perform the work related to gas, and the staffs who are in charge of this work have a risk of suffocation without cognizing incidents like gas leak. For example, when the nitrogen gas leaked in 2015 at Paju, two people were killed and four people were injured. In 2018 at Pohang, four workers were suffocated to death from nitrogen gas. In order to solve this problem, this study realized the system in which workers could immediately cognize the gas leak and also deliver the situation to the staff in charge of safety at the same time, by installing the IoT device composed of gas sensor and communication module on the safety helmet that should be worn by field workers. This study is expected to be able to reduce the casualties caused by gas leak in industrial sites.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2018.07a
• /
• pp.45-46
• /
• 2018

본 논문에서는 시간에 엄격한(Time critical) 산업용 IoT(Industrial IoT) 환경의 무선 센서 네트워크 시스템 상의 효율적인 패킷 전달과 정확도(Accuracy) 향상을 위해 강화학습과 EDF 알고리즘을 혼합한 스케쥴링 기법을 제안한다. 이 방식은 다중 대기열(Multiple queue) 환경에서 각 대기열의 요구 정확도(Accuracy Requirement)를 기준으로 최대한 패킷 처리를 미룸으로써 효율적인 CPU자원 분배와 패킷 손실율(Packet Loss)을 조절한다. 제안하는 기법은 무선 센서 네트워크 상의 가변적이고 예측 불가능한 환경에 대한 사전지식이 없이도 요구하는 서비스의 질(Quality of service)를 만족할 수 있도록 한다. 또한 정확도를 요구조건으로 제시하여 마감시간이 중요시되는 작업에서도 효율을 최대화한다.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.42 no.1
• /
• pp.21-32
• /
• 2019

The flow of the $4^{th}$ Industrial Revolution calls for the innovation of the traditional business models of the manufacturers. Servitization is a corporate strategy to respond to changes in the business environment. These days, the value that the market demands can be created on the basis of the product-service integration. Thus the manufacturers must pursue the fundamental innovation of the current strategy and business models. It is necessary to create common values with customers through providing product-service integrated offerings beyond the development, production, and delivery. The purpose of this study is to develop the evaluation indicators for selecting suppliers when the manufacturer who offers the value of product-service integration needs to obtain the resources from outside. The case company in this study is the manufacture firm conducting the retail IoT business as a new business. The Delphi method is used to develop the evaluation indicators for selecting suppliers. This study suggests the academic implications providing the perspective of Servitizaiton by using Delphi method, and the practical implications applying the creating value method of Servitization by collecting the opinions from both value providers and value consumers in the process of developing the evaluation indicators.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.19 no.5
• /
• pp.63-71
• /
• 2019

Recently, there has been a lot of research on the construction of smart factory in the 4th Industrial Revolution era. Among the various technologies involved in the deployment of smart factory, one of the key technologies is the IoT protocol sector that handles the transmission and reception of data. In this regard, the MQTT protocol is generally used most commonly, but the existing MQTT technology lacks the concept of priorities of messages, so it is somewhat insufficient to be applied to an industrial field requiring real-time property. Priority handling of urgent messages is critical, especially in emergency situations, such as the emergency shutdown of the entire relevant facility following the failure of a particular facility. To improve this, research on priority-based MQTT is being conducted somewhat, but these studies have problems with actual field use because they are a variant of the MQTT standard. Therefore, this study conducts and verifies studies related to MQTT, which can prioritize messages while adhering to existing MQTT standards.

• The Journal of the Convergence on Culture Technology
• /
• v.9 no.3
• /
• pp.789-795
• /
• 2023

Digital-Twin are recognized as an important core technology for the realization of Smart Factories by simulating and optimizing the monitoring and predictive maintenance of manufacturing equipment and the operation of production lines in a digital space. To implement this system, we adopt the IEC62541-based OPC-UA (Open Platform Communications Unified-Architecture) Protocol, which has strengths in interoperability and connectivity between heterogeneous platforms. Therefore, In this paper, We designed and implemented an IIoT(Industry Internet of Things) system that connects heterogeneous platforms, and developed an OPC-UA simulator based on IEC 62541. We will present whether the data will be applied to the Digital-Twin Platform and whether it will work, and proceed with performance tests and evaluations. We evaluate the operation performance and OPC-UA performance of the Digital-Twin platform lightened by the proposed device, and present the optimal IEC62514-based simulator system. We proceeded with the performance evaluation of sending and receiving data with OPC-UA wrapping with the proposed simulator, and found that a lightweight Digital-Twin platform can be operated. This research can apply the OPC-UA protocol for implementing smart factory and meta-factory in the manufacturing shop floor with limited resources, avoiding the waste of time and space on the shop floor through the OPC-UA simulator. We expect that this will contribute to a significant improvement in efficiency by minimizing.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2015.10a
• /
• pp.1095-1096
• /
• 2015

사물인터넷은 초고속 이동통신, 고감도 센서, 빅데이터 등의 발전과 함께 가시화되고 있으며, 사물인터넷의 핵심 요소인 플랫폼 기술이 대두되고 있다. 그러나 기존의 사물인터넷 플랫폼은 서로 다른 산업에 속하는 디바이스 및 응용 프로그램 간의 상호 운용성이 부족한 상황이다. 따라서 본 논문에서는 기존 사물인터넷 플랫폼의 문제점을 파악하고 차세대 개방형 사물인터넷 플랫폼에 대해 분석한다.

• Journal of Internet of Things and Convergence
• /
• v.6 no.2
• /
• pp.31-36
• /
• 2020

The remarkable change in the automobile industry, which is a traditional industrial field, is now evolving into a form of moving toward autonomous functions rather than humans due to various convenience functions and automatic driving or autonomous driving technologies if the person was central when driving the car. This situation is expanding to various industries such as the aviation industry and the drone market, as well as the robot market. The drone market in the aviation industry is being used in various fields due to the unmanned nature of drone operation. Among them, military drones are secret and due to the specificity of technology, details are not disclosed, but as a collection of advanced technologies, they have played a key role in drone development. In this study, the current status of China and the European Union, including the United States, which are major competitors in the drone field, was investigated, and the technologies of major countries were compared and analyzed through the characteristics and operational specifications of the drones currently in operation.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.25 no.3
• /
• pp.433-439
• /
• 2021

In this paper, we propose a method to implement an IoT-based sensor network for each workplace of a shipyard. Here, at the most common welding workplace in shipyards, the shipbuilding blocks are used as a communication medium to transmit information such as the worker's location, welding progress, and working hour to a server using LoRa and powerline communication. To achieve the data communication, inductive couplers and hybrid modems have been manufactured and installed on wire feeders and pin jigs to establish a sensor network. As a result of field test, the proposed system shows a success rate of data transmission and a rate of successful recognition of worker's location of about 98% or more. In addition, the process management system platform can record and display the work process data generated at the field in real time. The proposed system can be a starting point for enhancing the competitiveness of Korean shipbuilding industry through the establishment of a smart shipyard.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39C no.10
• /
• pp.920-929
• /
• 2014

Recently, embedded system which demand is explosively increasing in the fields of communication, traffic, medical and industry facilities, expands to cyber physical system (CPS) which monitors and controls the networked embedded systems. In addition, internet of things(IoT) technology using wearable devices such as Google Glass, Samsung Galaxy Gear and Sony Smart Watch are gaining attention. In this situation, Samsung Smart Home and LG Home Chat are released one after another. However, since these services can be available only between smart phones and home appliances, there is a disadvantage that information cannot be passed to other terminals without commercial global messaging server. In this paper, to solve above issues, we propose the structure of an indoor location network based on unit space, which prevents the information of the devices or each individual person from leaking to outside and can selectively communicate to all existent terminals in the network using IoT chatting. Also, it is possible to control general devices and prevent external leakage of private information.