• Journal of Biosystems Engineering
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• v.23 no.2
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• pp.157-166
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• 1998

In this study. a traveling control system was developed to transfer a machine without an operator in the working zone. The dimension of the system was modelized to design and construct smaller than that of real configuration of a greenhouse. For this system, the fixed path type was used to detect exact position during operating a manless machine. and the X-Y table actuator type to escape a unique path, which had the disadvantage in a fixed path type environment. Based on the results of this research the following conclusions were made : 1. This system used two screws to move toward horizontal direction, and a Plate to reach at any points in the working zone. 2. The software combined the functions of path selection and motor operation to control into one program. The path selection program was a menu driven program written in Visual Basic, and the motor operation program was written in Borland C++ for actuating motors. 3. The path-select mode of the program was used by selecting the desired paths, and the user path-create mode by selecting a random path in the path-selection program. 4. The system proved to be a reliable system for operating a manless machine, since accuracy and precision to reach the positions were less than 1%.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.5A
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• pp.593-601
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• 2000

In a multi-bandwidth CDMA system, the performance of multiple order selection combining rake receivers are analyzed according to the spreading bandwidth of the system and the delay spread of the Rayleigh fading channel. The results for various channel environments indicate a tradeoff between total received signal energy and multipath fading immunity. Increasing the occupied bandwidth of the system(wide-bandwidth spreading) gives better performance for small delay spread environments, while gathering more energy(narrow-bandwidth spreading)gives better performance for large delay spread environments. It is shown that the performance difference between low and high order selection combining grows larger as the spreading bandwidth increases. It is also noted that performance degrades by increasing the bandwidth above a certain point and the optimum spreading bandwidth for each channel environment decreases as the delay spread of the channel increases.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.5B
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• pp.327-337
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• 2012

There have been lots of researches on the optimal relay selection in relay-based systems. However, most researches have been focused on the maximization of transmission capacity with a constraint of sum power at both transmitter and relays. In Ad-hoc networks where relays have batteries of limited power, it is imperative to minimize the energy consumption while maintaining the required quality-of-service (QoS). In this paper, we propose an optimal relay selection strategy to minimize the relay power consumption while satisfying the required signal-to-noise ratio (SNR). Through intensive simulations, we show the proposed method is more effective in terms of energy consumption and guarantee lower transmission failure probability in multi-hop Ad-hoc environments.

• Journal of Satellite, Information and Communications
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• v.6 no.2
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• pp.91-96
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• 2011

In this paper, we present measurement method of the unknown load impedance. Load impedance is continuously varied by external environment conditions. This arbitrarily varied load impedance can be calculated using 3-point voltage measurement on ${\lambda}/4$ sectioned transmission line. We derived several numerical formulas from 3-point voltage measurement results and drew load impedance selection algorithm from calculated load impedance results. These numerical formulas and load impedance selection algorithm are verified by ADS simulation. Simulation results showed that arbitrary load impedance can be correctly measured using above mentioned formulas and selection algorithm.

• Journal of the Korean Society of Food Culture
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• v.36 no.4
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• pp.373-381
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• 2021

The number of vegans has increased rapidly due to religious and ethical beliefs, environmental concerns, health, etc. Also, as interest in healthy and safe food increases, the demand for organic products or nutrition-enhanced products is increasing. Therefore, this study aimed to investigate the selection attributes and purchasing behavior for protein-fortified and vegan snacks. It is anticipated that the results would find use as basic data for developing protein-fortified snacks for vegans that can meet consumer needs and derive marketing strategies. A survey was conducted on 140 consumers. According to the analysis of their purchase behavior, the number of people who had purchased high-protein snacks and vegan snacks was higher than those who did not have prior experience. The reasons for the purchase of protein fortified snacks included 'meal replacement' at 'offline-convenient store/supermarket'. Vegan snacks were purchased for 'ethical beliefs, health, environment' at 'offline-vegan restaurant, bakery'. Both snacks showed above-normal preferences. However, it is necessary to improve taste and flavor when developing these products as these were the factors that negatively impacted the preferences. The attributes were factorized into the 'showing off factor', 'sensory factor', 'credence factor', and 'functional factor' and the 'sensory factor' was considered the most important.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.9
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• pp.3151-3168
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• 2021

Internet of Things (IoT) connects several objects with embedded sensors and they are capable of exchanging information between devices to create a smart environment. IoT smart devices have limited resources, such as batteries, computing power, and bandwidth, but comprehensive sensing causes severe energy restrictions, lowering data quality. The main objective of the proposal is to build a hybrid protocol which provides high data quality and reduced energy consumption in IoT sensor network. The hybrid protocol gives a flexible and complete solution for sensor selection problem. It selects a subset of active sensor nodes in the network which will increase the data quality and optimize the energy consumption. Since the unused sensor nodes switch off during the sensing phase, the energy consumption is greatly reduced. The hybrid protocol uses Dijkstra's algorithm for determining the shortest path for sensing data and Ant colony inspired variable path selection algorithm for selecting active nodes in the network. The missing data due to inactive sensor nodes is reconstructed using enhanced belief propagation algorithm. The proposed hybrid method is evaluated using real sensor data and the demonstrated results show significant improvement in energy consumption, data utility and data reconstruction rate compared to other existing methods.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.1
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• pp.133-151
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• 2019

In order to achieve faster content distribution speed and stronger fault tolerance, a P2P peer can connect to multiple peers in parallel and receive chunks of the data simultaneously. A critical issue in this environment is selecting a set of nodes participating in swarming sessions. Previous related researches only focus on performance metrics, such as downloading time or the round-trip time, but in this paper, we consider a new performance metric which is closely related to the network and propose a peer selection algorithm that produces the set of peers generating optimal worst link stress. We prove that the optimal algorithm is practicable and has the advantages with the experiments on PlanetLab. The algorithm optimizes the congestion level of the bottleneck link. It means the algorithm can maximize the affordable throughput. Second, the network load is well balanced. A balanced network improves the utilization of resources and leads to the fast content distribution. We also notice that if every client follows our algorithm in selecting peers, the probability is high that all sessions could benefit. We expect that the algorithm in this paper can be used complementary to existing methods to derive new and valuable insights in peer-to-peer networking.

• Journal of Sport and Applied Science
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• v.5 no.2
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• pp.17-21
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• 2021

Purpose: This study aims to analyze the management environment Provincial and Municipal Professional Soccer Teams based on financial statements at a time when strengthening the financial soundness of domestic professional soccer teams is emphasized. Research design, data, and methodology: This study was sampled using convenience sampling and a total of 607 questionnaires were used. In this study, questionnaires were used as a survey tool, consisting of eight questions in a total of four areas, measuring demographic characteristics, shoe design, shoe functionality, shoe price, and promotion. Results: First, the importance of outdoor brand shoe selection attributes was high in cost-effectiveness, discount, and promotional models, while the satisfaction level was high in shoe size, content, and Model. Second, IPA analysis revealed shoe sizes, promotional models, and discount factors as maintenance and management continuation areas. Content factors have emerged as a competency-focused area. A sense of cushioning and wearing has emerged as an area of further improvement. As a status quo area, shoe laces and cost-effectiveness factors appeared. Conclusions: First, consumers considered the cost-effectiveness of choosing shoes, followed by discounts, and efforts are needed to diversify promotional content to maximize promotion for shoe sales. 3. Domestic outdoor brands are not yet satisfied with consumers.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.2
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• pp.347-353
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• 2022

Using the Heckman two-step procedure, this study investigates the relationship between management accounting implementation and firm effectiveness. The research data for this study was acquired from 450 publicly traded companies in Vietnam; however, the final sample only includes 304 responses containing useful information. The reliability analysis was used to evaluate the acquired data to examine the qualities of constructs and the dimensions that make them up. Then, the Heckman two-step technique was performed to analyze the causal connection from the acceptance of management accounting to firm effectiveness allowing for the effect of environmental uncertainty and organizational characteristics on the likelihood of adopting management accounting. The empirical findings show that management accounting acceptance determines firm effectiveness; however, the research model on the relationship between management accounting adoption and firm effectiveness has a sample selection bias. The main conclusions of this study are that there is a difference in the effects of management accounting adoption on business effectiveness when sample selection bias is not taken into consideration. When potential sample selection bias is taken into account by integrating environmental uncertainty and organizational characteristics in the research model, the effect of adopting management accounting on company effectiveness becomes minor.

• Journal of Internet Computing and Services
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• v.23 no.5
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• pp.9-15
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• 2022

This paper proposes a coordinated multi-point communication (CoMP) method with channel selection to improve performance of a macro user equipment (MUE) in a dense small-cell network environment in a building located within coverage of a macro base station (MBS). In the proposed CoMP method, in order to improve the performance of the MUE located in the building, A small-cell base station (SBS) selects a channel with lower interference to the neighboring MUE and transmits appropriate signals to the MUE requiring CoMP. Simulation results show that the proposed CoMP method improves the performance of the MUE by up to 164% and 51%, respectivley, compared to a random channel allocation based traditional SBS network and CoMP method.