• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.59 no.4
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• pp.387-398
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• 2023

Conventional aquaculture faces declining productivity, shifting to recirculating aquaculture system (RAS), known for minimizing water usage and maintaining consistent water temperatures for year-round fish growth. Rainbow trout (Oncorhynchus mykiss), a globally important cold-water species and the third most farmed fish in inland waters of Korea, valued for its fecundity and rapid growth. Dissolved oxygen, an important environmental factor affecting fish production and economics, highlights the need for smart aquaculture practices. Since 2018, the rise of intelligent aquaculture platforms, incorporating information and communications technology (ICT), emphasizes the essential role of RAS implementation. This eight-week study aimed to determine the optimal dissolved oxygen concentration for rainbow trout in RAS, utilizing a device for continuous monitoring, control and record. Dissolved oxygen concentrations were set at 5-6 mg/L, 9-10 mg/L, 14-15 mg/L and 17-18 mg/L. The growth rate significantly decreased at 5-6 mg/L, with no significant differences in other experimental groups. In hematological analysis, growth hormone (GH) was significantly highest at 5-6 mg/L, followed by 9-10 mg/L while Insulin-like growth factor-1 (IGF-1) was significantly lowest at 5-6 mg/L. In conclusion, the optimal dissolved oxygen concentration for rainbow trout in RAS is approximately 9-10 mg/L. Higher concentrations do not contribute to further growth or profitability.

• Journal of Advanced Navigation Technology
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• v.22 no.6
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• pp.507-513
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• 2018

The maritime autonomous surface ship is automatically collects and manages various information necessary for the operation to minimize human intervention and safely perform the mission assigned to the ship. And the ship may autonomously operate the partial or entire route to the destination determined by the ship himself. This ship navigation technology allows partially remote control the ship to be operated if necessary. The maritime autonomous surface ship (MASS) should collect and manage signals of various navigation communication equipments and engines mounted on the ship for safe operation. This requires a common platform technology. In this paper, we propose a common platform that is the core of smart ship implementation. Territorial authorities and ships are connected by satellite or terrestrial communication. In such a communication environment, information is exchanged smoothly in real time. This allows the onshore authorities to monitor ships and provide remote control to enable safe vessel navigation at sea.

• Journal of Korean Society for Quality Management
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• v.47 no.2
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• pp.237-254
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• 2019

Purpose: The purpose of this study is to analyze correlation of perceived cosmetics brand apps attributes and use intentions, mediating role of customer satisfaction, and relationship between customer satisfaction and continuous usage intention. Then provide basic data for development management strategy of beauty industry and enhancement of competitiveness corresponding to smart era. Methods: The questionnaires were surveyed by an online company(EMBRAIN). After data collection, frequency analysis was performed on the general attributes of questionnaire survey using SPSS 22.0, and data conclusions were derived by verifying reliability and validity of data and hypotheses. Results: First, perceived cosmetic brand app attributes have a positive effect on customer satisfaction, Second, perceived cosmetic brand app attributes have a positive effect on continuous usage intention. Third, customer satisfaction was found to have a mediating role in the effect of perceived cosmetic brand app attributes on continuous usage intention. Fourth, involvement proved to control the relationship between perceived cosmetic brand app attributes perceived interactivity and customer satisfaction. Finally, Involvement has proven to control the relationship between cosmetic brand app attributes perceived interactivity and continuous usage intention. Conclusion: Consumers buying products from cosmetics brand apps will be more likely to use cosmetics brand apps if they feel comfortable with calculation process, search, booking confirmation and payment methods.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.6
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• pp.39-44
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• 2011

This purpose of this study is to propose the characteristics analysis of the PCB pattern designed two modes for the output voltage value on the PMIC through converting the limited voltage value inputted from a battery. The PCB design technology has been undergoing difficulty in getting the related technology in a domestic market because of increasing EMI/EMC, Cross-talk, Impedance. And it requires to have the appropriate clearance between the patterns and the technology of PCB pattern width with a amperage according to various uses. The study carried out the characteristics analysis of the PCB pattern designed from a direct output method without a capacitor[mode1], to an output method through a capacitor[mode2] for PMIC output voltage value. Besides, we calculated the pattern width with a amperage using the equation suggested by IPC-2221, presenting the right way of the layout design to analyze the trouble with the test. Therefore, this study is expected to contribute not only to applying the PMIC design for the mobile panel power supply, but also helping the design and application technology in various areas such as car control, camera, note-book, computer, PDA, etc.

• Wind and Structures
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• v.36 no.3
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• pp.201-213
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• 2023

In this study, the effect of sea surface temperature (SST) on the distribution of vertical wind speed in the atmospheric boundary layer of coastal areas was analyzed. In general, coastal areas are known to be more susceptible to various meteorological factors than inland areas due to interannual changes in sea surface temperature. Therefore, the purpose of this study is to analyze the relationship between sea surface temperature (ERA5) and wind resource data based on the meteorological mast of Høvsøre, the test bed area of the onshore wind farm in the coastal area of Denmark. In addition, the possibility of coastal disasters caused by abnormal vertical wind shear due to changes in sea surface temperature was also analyzed. According to the analysis of the correlation between the wind resource data at met mast and the sea surface temperature by ERA5, the wind speed from the sea and the vertical wind shear are stronger than from the inland, and are vulnerable to seasonal sea surface temperature fluctuations. In particular, the abnormal vertical wind shear, in which only the lower wind speed was strengthened and appeared in the form of a nose, mainly appeared in winter when the atmosphere was near-neutral or stable, and all occurred when the wind blows from the sea. This phenomenon usually occurred when there was a sudden change in sea surface temperature within a short period of time.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.3
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• pp.37-51
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• 2017

We investigated how entrepreneurship, information technology acceptance, and media utilization influence on office worker commitment and how effects are modulated by learning orientation. The purpose of this study is to identify variables that influence on office worker commitment. To do so, entrepreneurship, information technology acceptance, and media utilization that are the core competencies of individuals and organizations in the era of smart information are proposed as predictor variables, office worker commitment as a outcome variable and learning orientation as a modulator. For this study, a questionnaire survey was conducted on office workers, and finally 340 valid questionnaires are used for analysis. Hierarchical regression analysis is used with demographic characteristics as control variables and learning orientation as a modulating variables. A result showed that the higher need for achievement and proactiveness of entrepreneurship is, the higher job commitment is and that the perceived usefulness of information technology acceptance and communication utilization ability of media utilization competitiveness have a positive effect on job commitment. A research showed that learning orientation is modulating the relationship between entrepreneurship and job commitment, and between media utilization capability and job commitment, respectively. We concluded that we should actively seek synergies of learning orientation along with accumulation of online communication utilization capacity and perceived usefulness of information technology, and of proactiveness need for achievement and in entrepreneurship in order to improve the work committment in the smart information society where the digital environment is advanced.

• Smart Structures and Systems
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• v.20 no.5
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• pp.619-636
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• 2017

Magnetorheological (MR) damper is a type of controllable device widely used in vibration mitigation. This device is highly nonlinear, and exhibits strongly hysteretic behavior that is dependent on both the motion imposed on the device and the strength of the surrounding electromagnetic field. An accurate model for understanding and predicting the nonlinear damping force of the MR damper is crucial for its control applications. The MR damper models are often identified off-line by conducting regression analysis using data collected under constant voltage. In this study, a MR damper model is integrated with a model for the power supply unit (PSU) to consider the dynamic behavior of the PSU, and then a real-time nonlinear model updating technique is proposed to accurately identify this integrated MR damper model with the efficiency that cannot be offered by off-line methods. The unscented Kalman filter is implemented as the updating algorithm on a cyber-physical model updating platform. Using this platform, the experimental study is conducted to identify MR damper models in real-time, under in-service conditions with time-varying current levels. For comparison purposes, both off-line and real-time updating methods are applied in the experimental study. The results demonstrate that all the updated models can provide good identification accuracy, but the error comparison shows the real-time updated models yield smaller relative errors than the off-line updated model. In addition, the real-time state estimates obtained during the model updating can be used as feedback for potential nonlinear control design for MR dampers.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.1
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• pp.155-161
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• 2015

The energy storage system is actively used as the widespread of smart grid. In the case of large scale EES, it can be efficiently controlled linked with BEMS or BAS. But, in the case of EES installed in a small sized household, it needs the help of the remote control system because it lacks the expert for controlling and operating of EES. In addition, in the case when the solar energy generation and EES are installed at the same time, a small sized EMS which can be efficiently controlled depending on the solar energy generation or electric power load is needed. In this paper, the EMS which can efficiently control the solar power generation as well as EES installed in a small sized household is implemented and its usefulness is verified through some experimental studies.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.4
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• pp.313-322
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• 2003

In this paper, the reverse link performance of imperfect power controlled cdma2000 cellular system that using array at a base station is analyzed, when MCGM beamforming algorithm and power control error is considered in shadowing. The blocking probability of the cdma2000 cellular system based on array parameters, E$\_$b//N$\_$0/ and interference statistics is calculated, and then the system capacity is calculated at a specific blocking probability. When the blocking probability is set 1 %, PCE(power control error) is 2 dB, M=2, 4, 8, 10, the capacity of cdma2000 is increased 2.3 ∼ 2.5 times higher than IS-95.

• Asia-Pacific Journal of Business
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• v.15 no.3
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• pp.101-120
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• 2024

Purpose - The purpose of this study was to examine the influencing factors on the revisit intention of unmanned convenience stores for Chinese consumers who use unmanned convenience stores. The effect of unmanned convenience store characteristics (operation system, store arrangement) on customers' perceived benefits and the effect of perceived benefits (convenience, speed, stability, playability) on revisit intention were verified. In addition, by using untact propensity as a control variable, the purpose of this study was to examine that the characteristics of unmanned convenience stores have a moderating effect on the perceived benefits of customers. Design/methodology/approach - The study collected 201 survey data from unmanned convenience stores in China. In order to analyze the data, Smart PLS was used to carry out empirical analysis. Findings - The results showed that operating systems had a positive impact on convenience, speed, and safety, while store layout had a positive impact on playfulness. Perceived benefits (convenience, safety, and playfulness) had a positive impact on their intention to revisit. Rapidity had a negative impact on the intention to revisit. Contactless tendencies regulate the effect of operating systems on convenience. Research implications or Originality - Unmanned convenience stores are striving to provide high-quality experiences to customers and increase customer satisfaction by utilizing cutting-edge IT technologies in stores such as AI, mobile device payment services, QR codes, and big data technologies. Recently, research on unmanned convenience stores has been active in the service and distribution industry-related fields, but research on the intention to revisit is insufficient. Also, few studies have used untact propensity as a control variable.