• Journal of Positioning, Navigation, and Timing
• /
• v.12 no.4
• /
• pp.379-389
• /
• 2023

According to the Korea Urban Air Mobility (K-UAM) Concept of Operation (ConOps), the Global Navigation Satellite System (GNSS) is recommended as the primary navigation system and the performance specification will be implemented considering the standard of Performance Based Navigation (PBN). However, by taking into account the characteristics of an urban environment and the concurrent operations of multiple UAM aircraft, the current PBN standards for civil aviation seem difficult to be directly applied to an UAM aircraft. Therefore, by referring to technical documents published in the literature, this paper examines the feasibility of applying the proposed performance requirements to K-UAM, which follows the recommendation of navigation performance requirements for K-UAM. In accordance with the UAM ConOps, the UAM aircraft is anticipated to maintain low altitude during approach and landing phases. Subsequently, the navigation performance degradation could occur in the urban environment, and the primary degradation factor is identified as multipath error. For this reason, to ensure the safety and reliability of the K-UAM aircraft, it is necessary to analyze the degree of performance degradation related to the urban environment and then propose an alternative aid to enhance the navigation performance. To this end, the aim of this paper is to model the multipath effects of the GNSS in an urban environment and to carry out the simulation studies using the real GNSS datasets. Finally, the initial navigation performance requirement is proposed based on the results of the numerical simulation for the K-UAM.

• Journal of Distribution Science
• /
• v.22 no.6
• /
• pp.33-44
• /
• 2024

Purpose: This study aims to measure how information quality, system quality, security, usefulness, and ease of use of Augmented Reality (VR) and Virtual Reality (AR) influence user satisfaction, motivating intelligent travel technology developers to improve VR/AR quality to meet customer requirements. Research design, data and methodology: This study investigates users interested in travelling in Ho Chi Minh City and Nha Trang City, Vietnam. The research model was implemented using an online questionnaire and face-to-face from 405 valid samples. To evaluate the scale's reliability, the study used the software SPSS 20. Test research hypotheses and evaluate measurement and structural models. This research uses AMOS 20 software. The proposed model is firmly grounded in the Information System Success model (ISS) and the Technology Acceptance Model (TAM), providing a solid theoretical foundation for our research. Results: Results show that consumer perceptions of information quality, system quality, security, usefulness, and ease of use have a positive impact on the perceived quality of VR/AR, thereby influencing tourists' travel intention. Conclusions: The results of this research enrich the theoretical understanding of consumer behaviour toward intelligent technology products in tourism, providing management implications for manufacturers to improve the quality of tourism products and satisfy user requirements in experience before considering choosing a destination.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.27 no.2
• /
• pp.247-255
• /
• 2024

Development of electronic warfare(EW) software has become increasingly challenging due to stricter regulations, shorter development cycles, and increased reliability testing. Consequently, software development often proceeds without proper architecture design, which can lead to missing critical quality requirements and potential system redesigns. In this study, we propose using Attribute-Driven Design(ADD) 3.0 to design software architecture specifically tailored for EW systems, enabling a more systematic approach to address quality requirements. The paper presents an overview of EW software and ADD 3.0 methodology, followed by an analysis of the architecture design results using static and dynamic views. The paper concludes by discussing the effectiveness of the proposed architecture design.

• Journal of Navigation and Port Research
• /
• v.39 no.3
• /
• pp.165-172
• /
• 2015

The class of Dynamic Positioning System is divided in 3 classes depending on its redundancy and reliability according to IMO and classification society. There are 3 DP classes such as DP Class 1, 2 and 3 according to IMO MSC/Circ. 645. Higher DP class vessel has higher reliability, since redundancy concept is applied to the DP vessel depending on its DP class and can operate more safely. There are not enough information about DP class notation, which are needed when a company builds a new or buys second hand DP vessel or modifies DP classes, even the Korean shipyard is building a lot of DP vessels now. Also, the practical case of DP vessel modification, which had been done in Korea, to meet DP notation of IMO and classification society, will be helpful for DP vessel modification and sales industry development in Korea as a new business. As such this research identified what kind of requirements need to be taken into account to be from DP class 1 to DP class 2. The real DP class modification case is used to identify the requirements of DP class upgrade. Through the FMEA the redundancy concept on power system, thruster system and DP control system need to apply for DP class upgrade. The power system have to keep its DP function even if just a single fault happens on the generator or switchboard. Also, the PMS is required to monitor and control power system. Ship's Surge, Sway and Yaw movements can be controlled by the remaining thruster system after a single thruster fails. Lastly, multiple installation of PRS, sensors and DP control system are required to keep DP ability after a single fault on the DP control systems.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.23 no.1
• /
• pp.174-179
• /
• 2009

Arterial pulse palpation is an important diagnostic method in Oriental Medicine, particularly for obtaining information about a patient's health conditions or illness, or for confirming a diagnostic conclusion based on the patient's pulsation. The pulse analyzer is both a leading Oriental Medical equipment and a promising tool with such a strong industrial ripple effect that it was selected as one of the four strategic tools for world Oriental Medical instrument market domination at a recent survey. Although various pulse analyzers had been developed, however, most of these were not widely used for clinical diagnosis, due perhaps to lack of the appliance's reliability caused by its inability to reflect the requirements of the clinicians. Thus, in this thesis, the clinical requirements for the pulse analyzer were identified and analyzed by conducting a questionnaire survey among Oriental Medicine clinicians. By looking into the basic functions of a pulse analyzer, the required measurement time, and the medical insurance fee required were determined and among others, the appliance's specific requirements were determined. Moreover, by investigating on the latest patent trend, the technical elements that are needed for the development of a next-generation pulse analyzer were identified. Through these processes, the flow of the technology that must be developed for the pulse analyzer was determined, and the direction for the development of the specific pulse analyzer hardware, sensor, and diagnostic algorithm was identified and proposed.

• Journal of the Korean Society for Railway
• /
• v.16 no.6
• /
• pp.519-527
• /
• 2013

Mobile radio technologies have evolved in the railway industry offering seamless connectivity and various functionalities to improve railway service. Recently, advanced mobile communication technologies have enabled a new level of railway customer services with more efficient railway operation. Since the LTE mobile communication technology offers many benefits and better performance for new railway services, it is considered to be a strong candidate for the future railway mobile telecommunication. However, communication networks in the railway sector are critical for secure operation and have stringent requirements for reliability and safety. In this paper, we explain the requirements for the future railway mobile telecommunication. The LTE, which would be the future railway mobile technology, is analyzed against these requirements. We also introduce the current state of standardization for the future railway mobile telecommunication and its implementation plan.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.38 no.4
• /
• pp.1-10
• /
• 2015

ISO 9001, quality management system, is widely known as advancing internal efficiency and productivity in various industry. As a result, the number of companies that have adopted ISO 9001's certification have been increasing continuously year by year since ISO 9000' family standard was published in 1987s. This fact shows that a lot of businesses are trying to get the accreditation for improving the competitiveness of quality. The purpose of this study is to present that ISO 9001's certification motives affect to the requirement's implementation and show that the execution of requirements influences on management performance in the small manufacturer. In order to carry out this research, we obtained 96 survey sheets and inspected twenty assumptions based on the reliability, validity of the questionnaires. The results of regression analysis are summarized as follows; First, the factors of certification motive influence on the requirement's implementation except resources management. Second, the two elements of ISO 9001 requirement, resources management and product realization, have an important effect on the operational performance and financial performance considerably in the companies that choose the internal motive. Finally, the two requisites of ISO 9001 requirement, resources management and measurement, analysis and improvement, affect to the operational performance and financial performance significantly in the businesses that select the external motive. Based on the results, the companies that choose the internal motive have a good performance to execute the ISO 9001 requirements. Also, to implement the requirements of ISO 9001 is helpful for the companies to produce the operational and financial performance.

• International Journal of Internet, Broadcasting and Communication
• /
• v.13 no.4
• /
• pp.103-111
• /
• 2021

In modern society, digital lifestyles are spreading to minimize contact with people and to receive contactless information. The spread trend has established an unmanned distribution system in which transactions through contactless technologies such as kiosks and chatbots are activated in face-to-face transactions with sellers and consumers. In order to streamline logistics supply worldwide, digital new deal based joint logistics hubs, unmanned courier storage platforms, and fresh logistics based last mile services have been developed into unmanned logistics systems, focusing on the intelligent logistics system automation process. Unmanned courier storage system installed in urban areas and home to daily logistics where volume is concentrated are provided with fresh logistics services through cold chain and receiving freights in contactless environments. Development is also underway to minimize safety accidents caused by courier services, such as managing various information based on the integrated control system. This paper defines the concept of integrated operation for the development of a platform for contactless unmanned courier storage device developed into next-generation logistics system. In addition, we intend to develop systems engineering-based output for deriving safety requirements and specifications by identifying risk sources that may occur in the operational scenario. Therefore, the goal is to establish a foundation for safety and reliability between interfaces of logistics systems to be installed in apartment and subway station environments that want to provide unmanned logistics services to various consumers.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.25 no.6
• /
• pp.628-636
• /
• 2022

This paper describes the design of the avionics architecture for military unmanned aerial vehicles considering the airworthiness requirements for the first time. This design considers the redundancy in the system data bus and the power system and the data link system to meet the system safety requirements of the airworthiness requirements of military UAVs. This avionics architecture design has been verified through the system integration test and the flight test after manufacturing the UAV.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.18 no.2
• /
• pp.376-380
• /
• 2004

The purpose of this study is the develop a questionnaire for measuring Yin-Deficiency and examine the reliability and validity for its' value as a barometer for evaluating Yin-Deficiency. Questionnaire was developed according to the symptoms of Yin-Deficiency suggested in the 'Standardization of diagnostic terms and requirements of Korean Medicine', With and as a reference, each symptom has been worked on to be put on the questionnaire. Visual analogue scales(VAS) was used as a barometer for measuring frequency of manifestation of symptoms. A study was performed to measure validity and reliability of the final questionnaire for analysis. reliability of YinDQ was measured by Cronbach's alpha coefficient and test-retest method. This study utilized factor analysis and clinical validity for evaluation of validity. For the purpose of decreasing the amount of data-the number of factors, and at the same time minimize the loss of information factor analysis was performed Component factors were extracted using Principal Component Analysis. This study evaluated the clinical validity for examination of difference between the normal group and the patient group. Evaluation on the's internal consistency showed strong internal consistency with value of 0.8615. reliability from test-rest with three-week interval, followed by comparisons of the correlation coefficient and mean values of each item between the two. The Spearman correlation coefficient was 0.54-0.79. By factor analyse two factors with Eigen value of greater than 2.2 were selected. Factor 1 consists of items of 'irritable fever on the five Hearts', 'flushing of the zygomatic region in the afternoon', 'tidal fever', 'night sweats', and 'dryness on the mouth or the throat'. Factor two consists of items of 'emaciation', 'dizziness', 'insomnia', 'decreased amount of urine with yellowish color', and 'constipation'. The comparison between the patient group and the normal group showed significant differences for every ten questions. The results implies that YinDQ is a barometer with sufficient reliability and validity. The questionnaire for Yin-Deficiency may not be enough to replace the specific differential diagnosis by a doctor of Oriental medicine. Nevertheless, it can be effectively utilized as an assisting method in consultation or a method of measuring the degree of Yin-Deficiency in a group.