• International journal of advanced smart convergence
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• 제9권4호
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• pp.184-191
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• 2020

With the emergence of the 4th Industrial Revolution, core technologies that will lead the 4th Industrial Revolution such as AI (artificial intelligence), big data, and Internet of Things (IOT) are also at the center of the topic of the general public. In particular, there is a growing trend of attempts to present future visions by discovering new models by using them for big data analysis based on data collected in a specific field, and inferring and predicting new values with the models. In order to obtain the reliability and sophistication of statistics as a result of big data analysis, it is necessary to analyze the meaning of each variable, the correlation between the variables, and multicollinearity. If the data is classified differently from the hypothesis test from the beginning, even if the analysis is performed well, unreliable results will be obtained. In other words, prior to big data analysis, it is necessary to ensure that data is well classified according to the purpose of analysis. Therefore, in this study, data is classified using a decision tree technique and a random forest technique among classification analysis, which is a machine learning technique that implements AI technology. And by evaluating the degree of classification of the data, we try to find a way to improve the classification and analysis rate of the data.

• International journal of advanced smart convergence
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• 제10권1호
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• pp.12-23
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• 2021

This paper proposes a low power radio frequency receiver front-end where, in a single stage, single-balanced mixer and voltage-controlled oscillator are stacked on top of low noise amplifier and re-use the dc current to reduce the power consumption. In the proposed topology, the voltage-controlled oscillator itself plays the dual role of oscillator and mixer by exploiting a series inductor-capacitor network. Using a 65 nm complementary metal oxide semiconductor technology, the proposed radio frequency front-end is designed and simulated. Oscillating at around 2.4 GHz frequency band, the voltage-controlled oscillator of the proposed radio frequency front-end achieves the phase noise of -72 dBc/Hz, -93 dBc/Hz, and -113 dBc/Hz at 10KHz, 100KHz, and 1 MHz offset frequency, respectively. The simulated voltage conversion gain is about 25 dB. The double-side band noise figure is -14.2 dB, -8.8 dB, and -7.3 dB at 100 KHz, 1 MHz and 10 MHz offset. The radio frequency front-end consumes only 96 ㎼ dc power from a 1-V supply.

• International journal of advanced smart convergence
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• 제11권3호
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• pp.206-214
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• 2022

Automobile manufacturers in each country are spurring the development of electric vehicles that use electric energy, an eco-friendly energy, as a futuristic vehicle. Electric vehicles have the advantage of no harmful gas or environmental pollution and low noise. Unlike automobiles using existing internal combustion engines using fossil fuels, electric vehicles use the electricity of batteries to cause rotational motion of motors. In the electric vehicle driven by the motor, it is indispensable to develop a controller for controlling the motor. One of the areas where automobile manufacturers are concentrating is the development of small electric vehicles as a personal transportation means. Small electric vehicles such as electric motorcycles, one-seat electric vehicles and two-seat electric vehicles are expanding the market as a means of operating throughout the city. In the domestic road conditions with many hills, it is effective to have a separate transmission system for small electric vehicles to drive smoothly. In this study, we propose a new type of continuously variable transmission(CVT) system to ensure that small electric vehicles can be driven smoothly in hilly domestic terrain. The proposed CVT system is equipped with a basic disk and a rotational disk in the driving pulley and the driven pulley, respectively, and is applied with a sloping spline to rotate the rotational disk. To commercialize the proposed CVT system, an experimental device was developed to examine the power transmission efficiency and the configuration of the CVT system was proposed.

• International journal of advanced smart convergence
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• 제11권3호
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• pp.215-221
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• 2022

In the manufacturing process of the bus treated as the commercial vehicle, after making the bare chassis which is the basic frame of the vehicle body, the part in which passengers ride is connected. In addition, the necessary parts such as the engine and transmission required for the operation of the bus are connected to the bare chassis. The element connecting the parts such as the boarding part of the passengers, the engine, the suspension and the transmission is the bracket. The device required for driving and operating the vehicle is mounted on the bare chassis using the bracket, which should ensure stability during bus operation. In this study, we were performed stress analysis to evaluate the stability of three types of brackets connecting the bare chassis of a new type of 30-seater bus in the development process and components required for driving and operation. The stress analysis should be preceded by the analysis of boundary conditions considering the loads applied to the brackets according to the material of the bracket to be analyzed and the driving type of the bus. The finite element model for structural analysis of brackets according to the driving type of the bus was used by Altair's Hypermesh 2017, and the solver used for structural analysis was Altair's Optistruct. The stress analysis was performed to present the safe and vulnerable parts of the three brackets.

• International journal of advanced smart convergence
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• 제11권3호
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• pp.1-6
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• 2022

In this paper, we estimate the mean number of objects in the M/H₂/1 model for web service when the mean object size in the M/H₂/1 model is equal to that of the M/G/1/PS and M/BP/1 models. To this end, we use the mean object size obtained by assuming that the mean latency of deterministic model is equal to that of M/H₂/1, M/G/1/PS, and M/BP/1 models, respectively. Computational experiments show that if the shape parameter of the M/BP/1 model is 1.1 and the system load is greater than 0.35, the mean number of objects in the M/H₂/1 model when mean object size of M/H₂/1 model is the same as that of M/G/1/PS model is almost equal to the mean number of objects in the M/H₂/1 model when the mean object size of M/H₂/1 model is the same as that of M/BP/1 model. In addition, as the upper limit of the M/BP/1 model increases, the number of objects in the M/H₂/1 model converges to one, which increases latency. These results mean that it is efficient to use small-sized objects in the web service environment.

• 방송과미디어
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• 제27권4호
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• pp.79-90
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• 2022

'스마트 기술(smart tech)'과 '도시화(urbanization)'라는 두 메가트렌드(megatrends)를 융합해 탄생한 스마트시티(smart city)가 전 세계적인 화두다. 스마트시티의 성장 가운데서 핵심적인 요소가 바로 '도시의 다양한 요소가 미디어(媒體, media)의 기능을 하는 커뮤니케이션이 중심이 된 도시'라는 점이다. 특히 메타버스 기술이 스마트시티에 접목되고 있음에 주목해야 한다. '초월'이라는 의미의 '메타(meta)'와 우주를 뜻하는 '유니버스(universe)'의 합성어인 메타버스(Metaverse)는 1992년 닐 스티븐슨(Neal Stephenson)의 소설 《스노우 크래쉬》에서 유래한 개념이라고 알려져 있다[1]. 메타버스는 정의하는 연구자에 따라서 크게 다르지만 흔히 '가상의 것(virtual thing)'으로 한정하는 경향이 있다. 하지만 최근에는 메타버스가 정치·경제·사회·문화 전반적 측면에서 오프라인의 현실과 온라인의 비현실 모두 공존할 수 있는 생활형·게임형 가상 융합 세계라는 의미로 보다 광의적으로 사용되고 있다. 최근 스마트시티의 변화를 보면 도시 운영이 고도로 지능화되고 다양한 콘텐츠가 증강되면서 <<도시 공간에서의 온라인과 오프라인의 경계 구분>>을 파괴하고 있음을 발견할 수 있다. 우리는 과거와 다름없이 물리적 도시 공간을 걷고 있지만 이제는 지형지물과 연결된 공간정보를 스마트폰으로 확인하고 또 도심의 디지털 사이니지(digital signage)를 통해 실시간 공공 및 상업 정보에 항시적으로 접하고 있다. 도시의 지향점으로 간주되는 스마트시티는 이제 일종의 '도시민 생활 플랫폼'으로 메타버스 기술과 융합 콘텐츠를 통해 도시민의 생활을 촘촘하게 연결한다. 본고에서는 '스마트시티가 메타버스 미디어 공간으로 기능하는 현상'을 '테코레이션(Tecoration: Technology + Decoration: 디지털 미디어 기술을 통한 도시 공간구축)'이라고 명명하려고 한다. 본고는 '메타버스 미디어 공간으로서 스마트시티 그리고 디지털 사이니지 테코레이션'을 주제로 '디지털 사이니지가 만들어 가는 스마트시티의 소통'과 관련된 주요 이슈를 다루려고 한다.

• International journal of advanced smart convergence
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• 제11권2호
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• pp.128-134
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• 2022

Nowadays, people consume a lot of content such as web dramas or K-pop videos through mobile devices such as smartphones, and the market for indirect advertisements through these web dramas or K-pop videos is also increasing every year. In order to lead to the immediate purchase of indirect products in web dramas, a system that allows consumers to purchase immediately at the time the products appear in the drama is needed. In this paper, we propose a system to allow viewers to purchase products worn by celebrities immediately when viewers see and click on them. When a user clicks on a video, it recognizes the product worn by the celebrity, and displays information on the screen on the most similar product corresponding to the recognized product, allowing them to go to the seller's site where they can purchase it. In order for such a system to operate stably, a pose estimation and siamese network-based system is proposed. The proposed system will primarily be released as a streaming service in the form of an app or web page that connects the products in web dramas or other K-pop video contents screened on the mobile with e-commerce. Furthermore, in the future, the technology is expected to be used globally in various industries such as smart mobility and display kiosks.

• International journal of advanced smart convergence
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• 제11권2호
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• pp.211-218
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• 2022

Pandemic situations such as COVID-19 can occur supply chain crisis. Under the supply chain crisis, delivering farm products from the farm to the city is also very challenging. Therefore it is essential to prepare food sufficiency people who live in a city. We firmly insist on food self-production/consumption systems in each home. However, since it is impossible to grow high-quality crops without expertise knowledge. Therefore expert system is essential to grow high-quality crops in home. To address this problem, we propose a smart kitchen farm as a data-based monitoring system and platform with ICT convergence technology. Our proposed approach 1) collects data and makes judgments based on expert knowledge for home users, 2) increases product quality of the smart kitchen farms by predicting abnormal/normal crops, and 3) controls each personal home cultivation environment through data-based monitoring within the smart central server. We expect people can cultivate high-quality crops in thir kitchens through this system without expert knowledge about cultivation.

• International journal of advanced smart convergence
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• 제11권2호
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• pp.95-101
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• 2022

The development of the 4th industry has increased social media, and the rise of COVID-19 has stimulated non-face-to-face services. People's consumption patterns are also changing a lot due to non-face-to-face services. In this paper, food content keywords are derived through social network-based semantic network analysis, emotions are analyzed, and keywords applied to food recommendation platforms are input. We collected food, influencer, and corona keyword analysis data through Textom. A lot of research has been done through online reviews of existing influencer content. However, there is a lack of research on keyword sentiment analysis provided by influencers rather than consumers and research perspectives. This paper uploads language and topics derived through online reviews of existing publications and subscribers, and goes beyond the limits used in marketing methods. By analyzing keywords that influencers suggest when uploading content, you can apply data that applies them to food recommendation platforms and applications.

• International journal of advanced smart convergence
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• 제12권3호
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• pp.211-220
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• 2023

Surface electromyography (sEMG) is a noninvasive method used to capture electrically muscle activity, which can be easily measured even during exercise. The basic unit of muscle activity is the motor unit, and because an sEMG signal is a superposition of motor unit action potentials, analysis of muscle activity using sEMG should ideally be done from the perspective of motor unit activity. However, conventional techniques can only evaluate sEMG signals based on abstract signal features, such as root-mean-square (RMS) and mean-power-frequency (MPF), and cannot detect individual motor unit activities from an sEMG signal. On the other hand, needle EMG can only capture the activity of a few local motor units, making it extremely difficult to grasp the activity of the entire muscle. Therefore, in this study, a method to visualize the activities of motor units in a single-channel sEMG signal by relocating wavelet coefficients obtained by redundant discrete wavelet analysis is proposed. The information obtained through this method resides in between the information obtained through needle EMG and the information obtained through sEMG using conventional techniques.