• International journal of advanced smart convergence
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• v.6 no.4
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• pp.88-95
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• 2017

The conventional scan methods are based on a laser scanner and a depth camera, which requires high cost and complicated post-processing. Whereas in photometric scanning method, the 3D modeling data is acquired through multi-view images. This is advantageous compared to the other methods. The quality of a photometric 3D model depends on the environmental conditions or the object characteristics, but the quality is lower as compared to other methods. Therefore, various methods for improving the quality of photometric scanning are being studied. In this paper, we aim to investigate the effect of illumination conditions on the quality of photometric scanning data. To do this, 'Moai' statue is 3D printed with a size of $600(H){\times}1,000(V){\times}600(D)$. The printed object is photographed under the hard light and soft light environments. We obtained the modeling data by photometric scanning method and compared it with the ground truth of 'Moai'. The 'Point-to-Point' method used to analyseanalyze the modeling data using open source tool 'CloudCompare'. As a result of comparison, it is confirmed that the standard deviation value of the 3D model generated under the soft light is 0.090686 and the standard deviation value of the 3D model generated under the hard light is 0.039954. This proves that the higher quality 3D modeling data can be obtained in a hard light environment. The results of this paper are expected to be applied for the acquisition of high-quality data.

• Journal of IKEEE
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• v.24 no.4
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• pp.1064-1068
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• 2020

For LW-TLM antenna of 65 kHz, Near-field propagation characteristics due to wave propagation obstacle are analyzed in this paper. The simulation modeling for propagation effects are based on the model of actual LW-TLM antenna which utilizes the frequency of 65 kHz, and the model expressed as propagation obstacle at a mountain height and a proximity of antenna and mountain. The near-field performance are analyzed based on the parameters of simulation model. In case of a normal mountain height and distance between the adjacent mountain and antenna site, a field strength change of about 1.7 dB has occurred. Above the constant distance of propagation obstacle and antenna, the wave propagation characteristics of disregarding the effects of propagation obstacle are shown. The results of this paper can be used to design and build a transmitting antenna site with 65 kHz operating frequency.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.2 s.344
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• pp.66-75
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• 2006

This paper addresses the implementation of FTTH system based on Ethernet PON technololy. This system consists of OLT and ONT. OLT supports the maximum 24 Gigabit Ethernet interfaces, and then has the flexibility and the scalability for supplying digital communication and broadcasting convergence service in the near future. OLT system consists of switch module, subscriber module, processor module, and E-PON link module, and has the operating system based on Linux. ONT is installed in customer premise to supply both IP-TV and Internet service. Also ONT has the dedicated interface for IP-TV to improve the transmission characteristics of IP-TV signal. We measure the performance of E-PON MAC through this system and then QoS control characteristics per franc in ONT by separating the virtual link for IP-TV from that for data.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.12C
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• pp.971-982
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• 2008

In this paper, we propose a new digital duplexing scheme, called SDD(Synchronous Digital Duplexing), which can increase data efficiency and flexibility of resource by transmitting uplink signal and downlink signal simultaneously. In order to transmit uplink data and downlink data simultaneously, the proposed SDD obtains mutual informations between AP(access point) and each SSs(subscriber station), SS and other SSs by mutual ranging procedure. These informations are used for selection of transmission time, decision of CS insertion, setting of CS length, and FFT duration resetting, etc. It is shown that the proposed SDD is appropriate for duplexing scheme in indoor environments over the conventional TDD(Time Division Duplexing) and FDD(Frequency Division Duplexing).

• International journal of advanced smart convergence
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• v.12 no.1
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• pp.18-30
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• 2023

We compared empirically the forecast accuracies of the LSTM model, and the ARIMA model. ARIMA model used auto.arima function. Data used in the model is 100 days. We compared with the forecast results for 50 days. We collected the stock closing prices of the top 4 companies by market capitalization in Korea such as "Samsung Electronics", and "LG Energy", "SK Hynix", "Samsung Bio". The collection period is from June 17, 2022, to January 20, 2023. The paired t-test is used to compare the accuracy of forecasts by the two methods because conditions are same. The null hypothesis that the accuracy of the two methods for the four stock closing prices were the same were rejected at the significance level of 5%. Graphs and boxplots confirmed the results of the hypothesis tests. The accuracies of ARIMA are higher than those of LSTM for four cases. For closing stock price of Samsung Electronics, the mean difference of error between ARIMA and LSTM is -370.11, which is 0.618% of the average of the closing stock price. For closing stock price of LG Energy, the mean difference is -4143.298 which is 0.809% of the average of the closing stock price. For closing stock price of SK Hynix, the mean difference is -830.7269 which is 1.00% of the average of the closing stock price. For closing stock price of Samsung Bio, the mean difference is -4143.298 which is 0.809% of the average of the closing stock price. The auto.arima function was used to find the ARIMA model, but other methods are worth considering in future studies. And more efforts are needed to find parameters that provide an optimal model in LSTM.

• International journal of advanced smart convergence
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• v.4 no.1
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• pp.137-144
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• 2015

Development of the yarn sorting equipment (khonhook) by slide way due to the principle of engineering that cause of workers on the long of motion time. The data was collected from the weaving group Ban Nongkok village, Nakornratchasima Province, THAILAND. According to the study, the step of yarn sorting (konhook) was one of the steps that affect long of motion time. The problem was the inadequate capacity equipment. The objective of research was to study and develop the yarn sorting equipment (konhook). The fabric used in the study was 64 meters in length and 1 meter in width. Researchers studied the processes the yarn sorting (konhook) which it consists of seven sub steps, 1) the thread tube setting, 2) yarn bunching, 3) tying a knot at the end of yarn, 4) looping the yarn into a pillar, 5) sorting the yarn (konhook), 6) crossing pillars and 7) taking out the yarn. Researchers focused on studying yarn sorting process (konhook) by designing and creating a device for yarn sorting (konhook) for reducing yarn sorting (konhook) time by the original method performance indicators. The results found that the developed yarn sorting equipment (konhook) ) by slide way could reduce working time from 7.24 minutes to 6.08 minutes of the original equipment yarn sorting (konhook). This means it could make the process 16.02 % faster. This also helps reducing the distance of workers' movement from 2,234 meters to 8 meters. This is 99.64 % shorter.

• International journal of advanced smart convergence
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• v.8 no.3
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• pp.123-130
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• 2019

In the study, we suggest that the activation plan of the public nature burial in the capital area through funeral information system as follows. First, according to the report on the social survey announced by the National Statistical Office in December 2017, the Korean people's preference of nature burial was 43.6% while the actual utilization rate of national nature burial in 2017 was only 8.8%, which showed a huge gap between preference and utilization rate of nature burial. Therefore, through the activities to improve the awareness of nature burial by performing the national promotion and education, and also the investment for the expansion or improvement of nature burial facilities in the level of central government and local government, the preference of nature burial should be led to the actual demand. Second, during the period from 2011 to 2018, the utilization rate of public nature burial in the capital area was annually increased by average 26.9%, which showed the huge increase of demand for nature burial. Thus, each local government should carry forward the policies for expanding the supply of public nature burial focusing on the woodland burial showing the high preference of users of public nature burial. Third, even though the public cremation facilities are installed or operated by local governments in the capital area, Seongnam City without the public cremation facilities should install the public nature burial for the enhancement of users convenience by providing the One Stop Total Funeral Service.

• International journal of advanced smart convergence
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• v.9 no.1
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• pp.82-89
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• 2020

This study is a design study related to the application of 3D printer technology for garment printing. Knitting, which used to be a home industry in the early days, originally comes from hand-knitting. This evolved with various personal devices as a small job for the self-sufficiency of early European housewives. In addition, since the Industrial Revolution, mechanical production entered the mass production mass supply system, and various apparel products were provided to consumers in accordance with mass standardized dimensions. This is similar to the development process in Korea. In addition, it has formed a considerable market with the situation that it can produce and supply apparel products at low labor costs of first-generation Namdaemun and Dongdaemun merchants. As the production shifted to the Southeast Asian region due to the increase in labor costs in the domestically developed social situation, the production of garment products in Korea is now almost 5%. As a result, apparel-related production facilities and related companies are constantly moving to other countries to move production facilities sensitively due to rising labor costs. Recently, smart factory automation has been planned to explore new possibilities. In addition, in recent years, with the evolved appearance of consumers, the appropriate supply of the right amount of production has appeared, and the 3D printer applied to personal garment output has attracted considerable interest in the customized market. Therefore, in order to become a new hope and a small addition to various clothing workers, this study conducted related research on the following 3D printers for clothing output and attempted to proceed with a new design.

• International journal of advanced smart convergence
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• v.11 no.3
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• pp.222-228
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• 2022

As a means to cope with the climate change crisis caused by global warming, automobile manufacturers continue to make efforts to use the driving energy of vehicles as electricity. As a result, parts industry such as battery, motor, and controller are attracting attention. China is often seen in large cities, with electric vehicles such as electric bicycles, electric motorcycles, and small electric vehicles popularized and commercialized, mainly in large cities. However, small electric vehicles are not popular in Korea, which is why the country's topography is high in hills. In order to drive the hilly domestic roads, power performance including vehicle climbing ability should be improved. In order to improve the power performance and the climbing capacity of small electric vehicles, the capacity of the motor should be increased. However, when the performance of the motor is improved, the weight of the motor becomes heavy and the price competitiveness is likely to decrease. In addition, in order to operate a high-performance motor, the power consumption of the battery is rapidly increased, so various problems must be solved. In order to commercialize a small electric vehicle for one or two people who do not emit harmful exhaust gas to the human body in a hilly domestic terrain, it is effective to have a separate transmission system. In this study, we were conducted dynamometer test to produce a continuously variable transmission(CVT) system prototype using a spring that can be applied to a small electric vehicle and to install a CVT system prototype manufactured in a small electric vehicle. The dynamometer test results showed that the maximum speed performance, acceleration performance, and climbing performance were improved.

• International journal of advanced smart convergence
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• v.8 no.2
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• pp.191-198
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• 2019

On the basis of 2017, the cremation rate in capital area was 89.0% which was much higher than the national average cremation rate(84.6%). Due to the short supply of cremation facilities in accordance with the increased number of cremation cases every year, the demand for cremation from the residents outside of the jurisdiction area with no cremation facilities was increased, so that the residents in the jurisdiction area had difficulties in using the Online Cremation Reservation Service in Funeral Information System. Thus, this study aims to make suggestions for policies as follows.First, on the basis of 2017, the demand-supply rate of cremation facilities in Gyeonggi-do was 139.4%, which means that the demand for cremation largely exceeds the ability to supply cremation. Therefore, first, in the level of Gyeonggi-do, the expanded supply of cremation facilities should be induced by carrying forward policies such as financial support to the basic local governments installing cremation facilities and expansion of incentives support to the residents of regions attracting cremation facilities. Second, it would be necessary for the central government to expansively conduct the support standard price and government subsidy rate(70%) for the new construction of cremation facilities and the establishment of cremation furnaces. Third, there should be some policies to decrease the inflow of residents outside of the jurisdiction area by raising the fee for using cremation facilities outside of the jurisdiction area of Seoul Metropolitan City and also expanding the application of a sliding scale of cremation hours.