• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.12
• /
• pp.310-319
• /
• 2020

Korea estimates the traffic noise by measuring the total traffic noise when the traffic passes (SPB; Statistical Pass-By). Another method (CPX; Close Proximity) directly measures the tire/road noise by installing a microphone near the tire. The CPX method is not a formal test method in Korea. There has been little research between CPX and SPB. This study proposes a method for estimating SPB, using the CPX, which is easy to measure. This study used the results of a large-scale test conducted by Korea Expressway Corporation (KEC) and a research paper on CPX in this section. The results by the KEC showed that the low noise pavement has a noise reduction of 10.4dB. In CPX research, the noise reduction was 10.7dB and was similar to 10.4dB in SPB. This study shows why the noise reduction is the same regardless of the position, the reason that the amount of noise reduction is similar, the difference of the noise according to the position of the microphone using the concept of noise summation and distance reduction. This study shows that including the CPX as a variable in the traffic noise prediction program is very important to improve noise prediction reliability.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.19 no.6
• /
• pp.96-106
• /
• 2020

To solve the limitation of traffic monitoring that occur from embedded sensor such as loop and piezo sensors, the thermal imaging camera was installed on the roadside. As the length of Class 1(passenger car) is getting longer, it is becoming difficult to classify from Class 3(2-axle truck) by using an embedded sensor. The collected images were labeled to generate training data. A total of 17,536 vehicle images (640x480 pixels) training data were produced. CNN (Convolutional Neural Network) was used to achieve vehicle classification based on thermal image. Based on the limited data volume and quality, a classification accuracy of 97.7% was achieved. It shows the possibility of traffic monitoring system based on AI. If more learning data is collected in the future, 12-class classification will be possible. Also, AI-based traffic monitoring will be able to classify not only 12-class, but also new various class such as eco-friendly vehicles, vehicle in violation, motorcycles, etc. Which can be used as statistical data for national policy, research, and industry.

• Convergence Security Journal
• /
• v.20 no.4
• /
• pp.227-236
• /
• 2020

Peacekeeping operations (PKO), which were based mainly on military operations in the Cold War era, have become diverse in the post-Cold War era. The history of the PKO of Korean police began in 1994 as two policemen were deployed to Somalia for rebuilding law and order in this country, but the role of Korean police in PKO has been limited so far, compared to that of Korean military. At this point when global conflicts escalate does the UN urge its 193 member states to conduct diverse PKO. In particular, maintaining law and order as the primary duty of police is required strictly for law enforcement while the warring country is being rebuilt. In this regard, some member states such as US, China, and Germany have deployed police force in order to play its role in a direct or indirect manner. On the contrary, the extent of the contribution of Korean police in PKO is too insignificant to measure. To this end, here in the present study were analyzed first the trend of global conflicts and the circumstance of law and order in the conflict regions. Then the PKO of police from countries including Republic of Korea, US, China, and Germany were compared, and so was the chronological change of PKO. Last, a measure to expand the capacity of Korean police and for its active role in PKO was proposed.

• Journal of Digital Convergence
• /
• v.19 no.3
• /
• pp.415-423
• /
• 2021

The purpose of this study was to report the changes in underwater anxiety, physical self-efficacy, and water safety consciousness in elementary school students through participation in survival swimming education, and the relationship between variables. For this purpose, 300 out of 312 elementary school students who participated in survival swimming education in Busan were used as valid samples. The collected data were analyzed through exploratory factor analysis, reliability analysis, correspondence sample t-test, and multiple regression analysis using the SPSS 25.0 statistical program, and the results are as follows. First, the underwater anxiety of elementary school students before and after participating in survival swimming education decreased, and the physical self-efficacy and water safety awareness increased. Second, underwater anxiety of elementary school students who participated in survival swimming education partially negatively affected physical self-efficacy and water safety consciousness, and physical self-efficacy partially positively affected water safety consciousness. Based on these results, the effectiveness of survival swimming education could be confirmed, and the direction of qualitative expansion of the program could be reconsidered.

• Knowledge Management Research
• /
• v.22 no.1
• /
• pp.287-308
• /
• 2021

This study aims to explore how the effects of the perceived social presence on trust and live chat adoption intention vary with the types of live chats in e-commerce context. As technology develops, live chat with the seller in e-commerce is rapidly replaced by AI-assisted live chat called chat-bot. However, it is not well known how the buyers perceive the difference between the chat with seller and the chat-bot. This study therefore proposes first, the perceived social presence toward the seller will influence trust and the live chat adoption. Second, the effects of social presence will be stronger when using live chat with seller than using chat-bot. To validate, we collect data from 232 e-commerce users and confirm the first proposition. However, the higher level of the social presence effect of live chat with seller is not clearly revealed. This study is expected to provide researchers and managers who are interested in AI-based chatbots with useful theoretical and practical implications.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.66 no.1
• /
• pp.1-7
• /
• 2021

The processing of rice is one of the measures to expand the scope of rice use in response to the decrease in rice consumption. Since the main ingredient of rice processing is rice flour, "rice flour varieties" have been bred with the aim to improve the productivity and quality of rice flour. In order to study the variation in the ripening characteristics of rice flour varieties with respect to temperature, the average temperature after heading date was set at 28℃ (33/23℃), 22℃ (27/17℃), and 18℃ (23/13℃) inside the phytotron. We used Saenuri as non-glutinous rice variety, Seolgaeng as soft-type rice flour variety, and Baromi2 as powdered rice flour variety. At high temperatures (28℃), the grain weight of Baromi2 decreased by 21%. Its starch content also decreased by more than 10%, which was significantly lower than that of Saenuri and Seolgaeng. At low temperatures (18℃), the grain weight and starch content slightly increased or were similar in all varieties. An analysis of changes in the grain weight due to effective accumulated temperature through the sigmoid function showed that the velocity of grain-filling slowed significantly when Baromi2 was exposed to low temperature during the ripening stage compared to the other varieties. Therefore, the transplanting time of Baromi2 should be delayed to avoid high temperatures during the ripening stage. However, because the ripening period is not properly secured under low temperature conditions, grain filling may not be sufficient.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.40 no.4
• /
• pp.251-258
• /
• 2020

To investigate the suitable growing area for Italian ryegrass (cv. Kowinearly and cv. Green-Call), we survey the different effects of climatic conditions on plant growth in the east (hereafter termed Yeongdong) and west (hereafter termed Yeongseo) of the passes in Gangwon Province. The Italian ryegrass was grown in Gangneung of Yeongdong and Wonju and Chuncheon of Yeongseo. The plants showed growth differences depending on the cultivated regions between before and after wintering. The Italian ryegrass for pre-wintering showed the relatively long length of plant height in Wonju. While, we observed the relatively tall plants for growing- and harvesting-period after wintering in Gangneung. The increased plant height in Gangneung was closely related to all climatic conditions for the growing period and mean- and lowest-temperature for the harvesting period, respectively. The amount of dry matter was 7,490 kg/ha for Kowinearly and 6,490 kg/ha for Green-Call in Gangneung, which has a higher yield than Chuncheon and Wonju. The relative yield index of dry matter was 77% (Kowinearly) and 78% (Green-Call) in Chuncheon and 84% (Kowinearly) and 71% (Green-Call) in Wonju compared to Gangneung as the standard region. Thus, we suggest that Chuncheon and Wonju are the possible areas for cultivation of Italian ryegrass, considering that Gangneung was the optimum growing area in Gangwon Province.

• Journal of the Korean Applied Science and Technology
• /
• v.38 no.1
• /
• pp.196-207
• /
• 2021

The purpose of this study is to investigate the relationship between trust, satisfaction and cognitive performance of golf participants in golf device, focusing on the swing analyzer. A total of 328 questionnaires were collected. Collected data were analyzed by SPSSWIN and AMOS program and frequency analysis, confirmatory factor analysis, validity test, correlation analysis and structural equation model analysis were performed. The result of the study were as follows. First, the trust of golf participants in golf device data has a positive effect on satisfaction. Second, the trust of golf participants in golf device data does not affect Perceived performance. Third, the satisfaction of golf participants in golf device data does not affect Perceived performance. In conclusion, golf participants' trust and satisfaction of the golf swing analyzer are irrelevant to the perceived performance. In conclusion, it was found that golf participants trusted the data presented through the golf device and obtained satisfactory results. However, in that it did not affect the perceived performance, golf participants can think that golf devices should be used to play golf rather than thinking that golf devices enhance their performance.

• Journal of the Korean Society of Radiology
• /
• v.15 no.4
• /
• pp.401-408
• /
• 2021

Proton therapy using the Bragg peak is one of the radiation therapies and can deliver its maximum energy to the tumor with giving least energy for normal tissue. A cross-sectional image of the human body taken with the computed tomography (CT) has been used for radiation therapy planning. The HU values change according to the tube voltage, which lead to the change in the boundary and thickness of the anatomical structure on the CT image. This study examined the changes in the Bragg peak of the brain region according to the thickness variation in the head phantom composed of several materials using the Geant4. In the phantom composed of a single material, the Bragg peak according to the type of media and the incident energy of the proton beams were calculated, and the reliability of Geant4 code was verified by the Bragg peak. The variation of the peak in the brain region was examined when each thickness of the head phantom was changed. When the thickness of the soft tissue was changed, there was no change in the peak position, and for the skin the change in the peak was small. The change of the peak position was mainly changed when the bone thickness. In particular, when the bone was changed only or the bone was changed together with other tissues, the amount of change in the peak position was the same. It is considered that measurement of the accurate bone thickness in CT images is one of the key factors in depth-dose distribution of the radiation therapy planning.

• Clean Technology
• /
• v.27 no.2
• /
• pp.174-181
• /
• 2021

This study analyzed the groundwater quality characteristics according to the main source of pollution and quarter (season) by using data from the pollution exclusive monitoring network in the Gyeongsangnam-do area for five years (2013-2017). The main source of pollution was the industrial complex areas, waste mines, and sewage treatment facilities. The analysis items were field measurement items (water temperature, pH, electrical conductivity, dissolved oxygen, oxide reduction potential), positive ions, and negative ions. Water temperature and pH did not vary significantly according to the main source of pollution. In industrial complex areas, the value of electrical conductivity was the highest, and dissolved oxygen value was the lowest. The mean concentration of positive and negative ions was the largest in industrial complex areas, followed by sewage treatment facilities and waste mines. It was shown that the concentration of sodium ion was the highest in industrial complex areas and calcium ion in waste mines and sewage treatment facilities. The concentration of bicarbonate ion was the highest in all main sources of pollution. Water temperature, pH, and concentrations of cations and anions did not vary significantly from quarter to quarter. Of the water quality types, the Na-HCO₃ type accounted for the highest proportion, but the Na-Cl type, which has a high possibility of external contamination, accounted for about 20% of the total data in the pollution exclusive monitoring network.