• Journal of Navigation and Port Research
• /
• v.39 no.6
• /
• pp.457-463
• /
• 2015

A gas turbine engine plays an important role as a prime mover that is used in the marine transportation field as well as the space/aviation and power plant fields. However, it has a complicated structure and there is a time delay element in the combustion process. Therefore, an elaborate mathematical model needs to be developed to control a gas turbine engine. In this study, a modeling technique for a gas generator, a PLA actuator, and a metering valve, which are major components of a gas turbine engine, is explained. In addition, sub-models are obtained at several operating points in a steady state based on the trial running data of a gas turbine engine, and a method for controlling the engine speed is proposed by designing an NPID controller for each sub-model. The proposed NPID controller uses three kinds of gains that are implemented with a nonlinear function. The parameters of the NPID controller are tuned using real-coded genetic algorithms in terms of minimizing the objective function. The validity of the proposed method is examined by applying to a gas turbine engine and by conducting a simulation.

• KIPS Transactions on Software and Data Engineering
• /
• v.9 no.11
• /
• pp.357-366
• /
• 2020

As the proportion and complexity of software embedded in aircraft increase, risk factors such as mission failure, function failure and performance failure due to software errors also increase. In the mission-critical software systems such as aircraft software, managing requirement traceability is essential to maintain the software systems with minimal period and cost. However, the development company is not accurately complying with the guideline for managing requirement traceability due to various reasons such as development cost and schedule. Therefore, it is not easy to systematically establish and maintain requirement traceability. In the paper, we analyze actual test cases of aviation software systems from the viewpoint of requirements traceability in order to learn if there are failure cases of test cases due to the absence of systematic traceability management activities. We also check the risks associated with the failure cases according to the type and severity of the cases. As a result of analyzing a total of 7 aircraft-mounted software, failure cases could be divided into three types: omission of requirements, lack of connection between requirements and test procedures, and omission of test procedures. There were a total of 18 failure cases, 6 for each type. The numbers of high, middle and low risks were 1, 13 and 4, respectively, where the number of middle risks is largest.

• International Journal of Highway Engineering
• /
• v.11 no.1
• /
• pp.165-175
• /
• 2009

With the current move towards adopting mechanistic-empirical concepts in the design of pavement structures, state-of-the-art mechanistic analysis methodologies are needed to determine accurate pavement responses, such as stress, strain, and deformation. Previous laboratory studies of pavement foundation geomaterials, i.e., unbound granular materials used in base/subbase layers and fine-grained soils of a prepared subgrade, have shown that the resilient responses followed by nonlinear, stress-dependent behavior under repeated wheel loading. This nonlinear behavior is commonly characterized by stress-dependent resilient modulus material models that need to be incorporated into finite element (FE) based mechanistic pavement analysis methods to predict more realistically predict pavement responses for a mechanistic pavement analysis. Developed user material subroutine using aforementioned resilient model with nonlinear solution technique and convergence scheme with proven performance were successfully employed in general-purpose FE program, ABAQUS. This numerical analysis was investigated in predicted critical responses and domain selection with specific mesh generation was implemented to evaluate better prediction of pavement responses. Results obtained from both axisymmetric and three-dimensional (3D) nonlinear FE analyses were compared and remarkable findings were described for nonlinear FE analysis. The UMAT subroutine performance was also validated with the instrumented full scale pavement test section study results from the Federal Aviation Administration's National Airport Pavement Test Facility (FAA's NAPTF).

• Journal of Food Hygiene and Safety
• /
• v.33 no.2
• /
• pp.89-93
• /
• 2018

High sodium dietary habits may cause various diseases, thereby threatening the public health. Various efforts have been made to control high sodium use in diets, but few studies have been conducted on health communication efforts to modify such habits. This study looks for suggestions for diet improvement education by examining whether or not high sodium dietary habits can be predicted by a consumer's perception on the threat and controllability of high sodium diets. In this study, a questionnaire was developed to measure the severity, vulnerability, efficiency, efficacy, and behavioral tendencies of the consumer, which were subscales of the protective motivation theory. The questionnaire was given to university students and their families in Chungnam Province. The results of a statistical analysis were as follows: First, more young people preferred high-sodium diets than older people. Second, the correlation analysis showed that older people knew that they were vulnerable to the negative effects of high sodium diets, but they would not change their dietary habits until they were confident that they could control the high-sodium diet. Third, the structural model analysis showed that the higher the coping perception was, the lower was the tendency to consume a high-sodium diet. These results suggest that in the effort to reduce high-sodium diets, it is more effective to provide viable information and improve efficacy.

• Journal of Advanced Navigation Technology
• /
• v.17 no.6
• /
• pp.625-632
• /
• 2013

Since GBAS is a navaid facility to provide precision approach service to aircrafts landing at airports, it must be approved by the air navigation service provider or the aviation regulator to be declared operational. However, Korea has no experience in developing or operating the system so there is no approval criteria for GBAS. In order to develop the criteria in case of the future GBAS procurement, Korea Aerospace Research Institute has been testing the installed commercial GBAS station, SLS-4000, in Gimpo International Airport. This paper summarizes the criteria development results focusing on the system design approval. The criteria have been outlined based on the other leading nations' cases and documentations and established in detail on the basis of the FAA SDA artifacts. Those will be directly used for GBAS approval procedure in Korea and are expected to be useful in system requirement analysis, design, development and artifact management in case of own GNSS-based navaid system development in the future.

• Journal of Distribution Science
• /
• v.12 no.8
• /
• pp.103-112
• /
• 2014

Purpose - There have been local government systems since June 1955. Many local governments have made use of festivals for regional public relations and the achievement of competitiveness. This study analyzes effective components of local festivals. There has been extensive research in relation to variables such as participation motivation, satisfaction level, recall intention, royalty, and recommend purpose. However, as a variable factor, attachment to the participation motivation of a festival has been overlooked along with support level to a festival. This study has added new variables named "attachment to local society" and "support level," which are dependent variables. We will study the relationship of these two variables. Research design, data, and methodology - This study has devised a cause-and-effect relationship model, which deduces that local residents' participation motivation for the festival will have positive influence on the festival support level and satisfaction level. We circulated questionnaires to local residents to get the data required to prove the hypothesis. To analysis the data, we used SPSS 21.0, and accomplished basic analysis through the analysis of frequency as well as descriptive statistical analysis. Further, we verified our measurement tools through reliability analysis, and examined the research hypothesis through multiple regression analysis. Results - With regard to the festival satisfaction level, the variables of local society attachment, festival attraction, escaping from the daily life, and family harmony have influence upon a positive effect (+) in this order. Among them, the variable of local society attachment has the greatest influence. However, in respect of support level for the festival, only the variables of local society attachment and escaping from the daily life have a valid influence on the positive effect (+), and local society attachment has relatively greater influence. In addition, not only does the festival satisfaction level affect the support level for the festival in terms of positive effect, the influence is also far-reaching, which verifies the mediating effect. Conclusions - The result shows that the local residents' satisfaction level with the Yudalsan Mountain Spring Flower Festival is comparatively high, which is due to the local society attachment. It also shows that it is difficult to create support without local residents' attachment with their area. Consequently, this study insists that the Yudalsan Mountain Spring Flower Festival should exceed its limitation as just a village-level party, in order to become a remarkable and outstanding festival, and suggests three operational implications: macro-environmental development, task environment development, and internal operational environmental development. From the macro-environmental perspective, the constant development of local culture and local business is proposed. In the task environment perspective, a new functional development for the festival is proposed. From the internal operational environmental perspective, improvements in festival operation methods are proposed. If these weak points are addressed and resolved through a more detailed approach, it will be very helpful for local government systems to operate the festival.

• Korean Journal of Remote Sensing
• /
• v.35 no.5_1
• /
• pp.751-761
• /
• 2019

Mt. Baekdu, Mt. Aso, Mt. Sakurajima, Mt. Kikai and etc are distributed around the Korean Peninsula. Recently signs of eruption of Mt. Baekdu are increasing, raising concerns over possible damage to volcanic ash from seasonal winds during the winter eruption. Therefore, detailed procedures for investigation and countermeasures for volcanic ash spread and damage are required. But the standards for the warning and alarm signal of volcanic ash presented by Korea Ministry of Government Legislation are vague, with "when damage is expected" and "when serious damage is expected". In this study, to analyze the damage threshold and to apply the cases of overseas damage to the country, a survey was conducted on the establishment of domestic spatial information by public institutions with public confidence. As a result of the investigation of damage from volcanic ash overseas, the details of the damage cases were different depending on the type of life or income sources of each country. Therefore, instead of applying the volcanic ash damage cases abroad in Korea, spatial information analysis was performed to reflect domestic social and natural characteristics. In addition, we selected the areas to be considered in the event of volcanic ash damage in Korea. Finally, domestic volcanic ash damages should be classified as health, residential, road, railroad, aviation, power, water, agriculture, livestock, forest, and soil. When establishing the volcanic ash alarm optimized for Korea in the future, overseas volcanic ash damage cases and domestic spatial information construction in this study will be helpful in policy establishment.

• The Journal of the Korea Contents Association
• /
• v.19 no.10
• /
• pp.21-31
• /
• 2019

With the development of the aviation industry, aircraft painting design also plays the role of transmitting the national image while conveying the individual image of the airline. The recognition and recognition of the national image can be obtained by building a national brand. As a result, more and more companies are using the national brand image of their own country or other countries to add value to the company. Objective: To better reflect the national brand recognition for the design of the tail fin in the future aircraft painting design. This paper mainly studies the correlation between the tail graphic elements of aircraft painting design and national brand recognition based on the tail graphics of the three major airline alliance members. Based on the prior research, the relevant hypotheses were proposed and the questionnaire was designed. Secondly, a questionnaire survey was conducted on the passengers using the aircraft, and the correlation analysis was performed on the data by the SPSS regression analysis method. Conclusion: Data analysis has a strong correlation.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.24 no.4
• /
• pp.398-407
• /
• 2018

Standard guidelines for marine accident investigation have been prepared through the enforcement of the Casualty Investigation code as of January 2010. In addition, as the International Maritime Organization (IMO) recommended contracting the state to manage a marine incident system established under this code, Korea also has newly established provisions for a marine incident system in the 'Act on the Investigation of and Inquiry into Marine Accidents' also as of 2010. The Korean Maritime Safety Tribunal (KMST) has made a multilateral effort to prevent marine accidents through the efficient operation of a marine incident system, but this system has not been properly activated. This study examines the operational status and problems of a marine incident system and analyzes the marine incident systems of foreign countries and similar transportation agencies such as railroads and aviation. Options include switching to voluntary reporting of marine incidents, transferring responsibility to a non judicial private organization, expanding incentive systems for a marine incidents, revising regulation and preparing detailed implementation guidelines.

• Journal of the Korea Society of Computer and Information
• /
• v.25 no.6
• /
• pp.9-15
• /
• 2020

In this paper, we propose a case that drone (unmanned aerial vehicle), one of the representative technologies of the 4th Industrial Revolution, threatens airport safety and privacy infringement, and describes a drone control system proposal to solve the problem. Unmanned aerial vehicle (Drone) is creating a serious problem recently, In Korea, on May 21, 19, according to the Jeju Regional Aviation Administration, drones flew over Jeju Jeongseok Airfield twice in the same month, causing problems in aircraft operation. In overseas cases, two drones near the runway of Gatwick International Airport in the UK There has been a disturbance in which the takeoff and landing of the aircraft flies for a while, and various problems have occurred, such as voyeuring the private life of an individual using a drone. This paper is equipped with an Acess Point transponder mounted on a drone (unmanned aerial vehicle), and unspecified many who want to receive flight information (coordinates, altitude, and obstacles) of the drone access the drone AP, receive and receive the flight information of the drone, and receive unspecified multiple Drone AP flight information is collected and collected to provide the information of the drone currently floating on one user interface screen. In addition, an AP transponder is proposed to operate a safe drone (unmanned aerial vehicle) and the drone's flight information is transmitted., To receive and collect and collect data.