• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.9
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• pp.21-27
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• 2022

The rotorcraft engine gearbox transmits the power generated by the turboshaft engine to the rotor by reducing the rotational speed and increasing the torque. The core of the rotorcraft engine gearbox is lightweight performance, which requires maximum weight reduction within the range that meets various requirements and constraints. Therefore, lightweight design through gear macro geometry optimization is necessary. In this study, gear macro geometry optimization was performed to reduce the weight of a rotorcraft engine gearbox. NSGA-III was used for the optimization, resulting in a combination of the gear ratio and macro geometry that minimizes the weight of the total gear. In addition, the safety factor of the gears satisfied the given conditions.

• Journal of the Korean Operations Research and Management Science Society
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• v.17 no.2
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• pp.145-162
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• 1992

This paper proposes two design principles for expert systems to solve a stock market timing (SMART) problems : machine knowledge and fuzzy post-adjustment, Machine knowledge is derived from past SMART instances by using an inductive learning algorithm. A knowledge-based solution, which can be regarded as a prior SMART strategy, is then obtained on the basis of the machine knowledge. Fuzzy post-adjustment (FPA) refers to a Bayesian-like reasoning, allowing the prior SMART strategy to be revised by the fuzzy evaluation of environmental factors that might effect the SMART strategy. A prototype system, named K-SISS2 (Knowledge-based Stock Investment Support System 2), was implemented using the two design principles and tested for solving the SMART problem that is aimed at choosing the best time to buy or sell stocks. The prototype system worked very well in an actual stock investment situation, illustrating basic ideas and techniques underlying the suggested design principles.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.3
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• pp.121-126
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• 2019

Recently IoT named Internet of Things technology is widely used throughout the industry. In this paper, a smart vending machine system is proposed to solve inconvenience of vending machine which is commonly seen. This allows users to purchase goods without cash and saves management costs by allowing vending machine managers to stock and sell conveniently. For the production of this smart vending machine, Analysis example using UML which is object-oriented analysis method and flowchart and screen design applying it are presented. Also this presented method is shown to being applied usefully for a guideline of building smart vending machine commercialization system based on IoT.

• Smart Structures and Systems
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• v.14 no.4
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• pp.517-539
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• 2014

The combined use of smart materials, complementing each others' characteristics and resulting in devices with optimised features, is providing new solutions in many industries. The use of ingenious combinations of smart materials has led to improvements in actuation speed and force, signal-to-noise ratio, sensor precision and unique capabilities such as self-sensing self-healing systems and energy autonomy. This may all give rise to a revival for numerous families of smart materials, for which application proposals had already reached a stationary situation. It may also provide the boost needed for the definitive industrial success of many others. This study focuses on reviewing the proposals, preliminary studies and success cases related to combining smart materials to obtain multifunctional, improved systems. It also examines the most outstanding applications and fields for the combined use of these smart materials. We will also discuss related study areas which warrant further research for the development of novel approaches for demanding applications.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.5
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• pp.1516-1539
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• 2022

This article shows a set of physical information fusion IoT systems that we designed for smart buildings. Its essence is a computer system that combines physical quantities in buildings with quantitative analysis and control. In the part of the Internet of Things, its mechanism is controlled by a monitoring system based on sensor networks and computer-based algorithms. Based on the design idea of the agent, we have realized human-machine interaction (HMI) and machine-machine interaction (MMI). Among them, HMI is realized through human-machine interaction, while MMI is realized through embedded computing, sensors, controllers, and execution. Device and wireless communication network. This article mainly focuses on the function of wireless sensor networks and MMI in environmental monitoring. This function plays a fundamental role in building security, environmental control, HVAC, and other smart building control systems. The article not only discusses various network applications and their implementation based on agent design but also demonstrates our collaborative information fusion strategy. This strategy can provide a stable incentive method for the system through collaborative information fusion when the sensor system is unstable in the physical measurements, thereby preventing system jitter and unstable response caused by uncertain disturbances and environmental factors. This article also gives the results of the system test. The results show that through the CPS interaction of HMI and MMI, the intelligent building IoT system can achieve comprehensive monitoring, thereby providing support and expansion for advanced automation management.

• Journal of Korea Multimedia Society
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• v.16 no.2
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• pp.190-197
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• 2013

Since domestic and foreign platform companies and mobile carriers adopt and use different kinds of smart platforms, developers should develop or convert contents according to each smart platform to provide a single smart content for customers. It takes long time and a lot of money to convert the conventional smart contents in order to serve other smart platforms. For the reason, more attention has been paid on Smart Cross Platform or Hybrid Platform, the core technologies of OSMU(One Source Multi Use) in which, once a program is coded, it can be executed in any platforms regardless of development languages. As a result, PhoneGap and HTML5 based Sencha Touch have been introduced. In this paper, we developed the smart virtual machine, which is built in smart cross platform based smart devices, unlike Android, iOS, Windows Phone devices being dependent of platforms, and helps to download and execute applications, being independent of platforms. the smart virtual machine supports C/C++, and Java language, being differentiated from JVM by sun microsystems that supports only Java language and .NET framework by microsoft that supports only C, C++ and C#. Therefore, it provides contents developers with the environment where they can get a wide range of options in choosing a language and develop smart contents.

• Smart Media Journal
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• v.12 no.1
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• pp.47-53
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• 2023

Recently, research on a smart farm that creates new values by combining information and communication technology(ICT) with agriculture has been actively done. In order for domestic smart farm technology to have productivity at the same level of advanced agricultural countries, automated decision-making using machine learning is necessary. However, current smart greenhouse data collection technologies in our country are not enough to perform big data analysis or machine learning. In this paper, we design and implement a smart greenhouse data preprocessing system for autonomous machine learning. The proposed system applies target data to various preprocessing techniques. And the proposed system evaluate the performance of each preprocessing technique and store optimal preprocessing technique for each data. Stored optimal preprocessing techniques are used to perform preprocessing on newly collected data

• Journal of the Korean Society of Industry Convergence
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• v.23 no.3
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• pp.507-513
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• 2020

Liquid filling machines are frequently used in packaging fields; however, there exists a problem in precisely measuring the quantity of the liquid. In the case where the liquid filling machine is not properly metered, there may be issues, such as the fluid exceeding the capacity or chemicals being exposed outside. In this paper, we propose a smart injection nozzle device that can solve the issues stated above. The proposed smart injection nozzle can raise the nozzle according to the water level to remove bubbles and inject the accurate amount of fluid. In addition, the efficiency of the logistics process is enhanced by the smart QR code. Through experiments using the developed smart injection nozzle device, we have noticed that the accuracy of injection capacity, nozzle position, reaction time and building data exceeded the target value. Therefore, it expected that this machine will give more production and save a lot of manpower for packaging industry.

• International Journal of Advanced Culture Technology
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• v.7 no.1
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• pp.209-215
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• 2019

In order to provide a safe free-weight-training environment to people without workout trainers, we suggest a smart bench press machine with an automatic weight control system sensitive to user tiredness. Physical weight plates on the machine are replaced with a hydraulic cylinder as a press load and the cylinder knob is coupled with a step motor to change its tensile force automatically in-between lifting exercises. Three subjects participated to verify the usability of the smart bench press machine. They were asked to lift a 6-RM press load 10 times with 3 different lifting conditions: 1) no assistance, 2) a human assistance, and 3) the automatic weight control. All subjects were not able to complete the 10 sets without assistance due to tiredness, but they finished the full sets under the two assistive conditions. Average lifting speeds under the automatic weight control condition showed the most consistent level. Normalized quasi-tension data based on surface electromyogram signals of both Pectoralis Majors revealed that the subjects maintained the target muscle activation level above 50% but not more than 80% throughout the 10 sets. Therefore, the smart bench press machine is expected to both keep pace with the lifting exercise and reduce risk of injuries due to excessive muscle tensions.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.4
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• pp.1017-1023
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• 2015

The amount of smart phones has increased exponentially. Due to the periodic release of high-performance smart phones and upgraded operating system, new smart phones become out-dated over 1 or 2 years. In order to solve environmental constraints of these smart phones, virtualization technology using Thin-Client terminal has been developed. However, in the case of Virtual Machine(VM), the applications associated with sensors and a GPS device can not run because they are not included. In this paper, by implementing the device driver for Android running in a virtual machine in the x86-based systems, it is to provide Android virtualization capabilities such as using the latest smart phones in the virtual machine environment. It would like to propose a method that the virtual device driver receives sensors and GPS information from the old Android smart phones(Thin-Client) that actually work and run as if the real device exists.