• Journal of the Korea Society of Computer and Information
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• v.16 no.12
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• pp.227-234
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• 2011

Many technologies for wireless internet are increasing as more and more laptop computers, net books, smart phone and other terminals, which provide wireless network, are created. IEEE 802.11 is computer wireless network technology that used in small area, called wireless LAN or Wi-Fi. IEEE 802.11 is a set of standards for implementing wireless local area network (WLAN) computer communication in the 2.4, 3.6 and 5 GHz frequency bands. They are created and maintained by the IEEE LAN/MAN Standards Committee (IEEE 802). AP (Access Point) is installed at cafes and public places providing wireless environment. It is more convenient to use wireless internet, however, It can be seen easily around us and possible to communicate with AP. IEEE 802.11 has many vulnerability, such as packet manipulation and information disclosure, so we should pay more attention when using IEEE 802.11. Therefore this paper developing monitoring system which can find out AP and Stations that connect with it, and capturing AP's information to find out vulnerability. This paper suggests monitoring system which traffic analysis in wireless environment.

• Journal of Biosystems Engineering
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• v.41 no.4
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• pp.313-318
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• 2016

Purpose: This study measured and analyzed the PTO (power take off) torque of a transplanter according to the planting conditions during field operation. Methods: A torque measurement system was constructed with torque sensors to measure the torque of a PTO shaft, a measurement device to acquire sensor signals, and a power controller to provide power for a laptop computer. The field operation was conducted at four planting distances (26, 35, 43, and 80 cm) and two planting depths using the transplanter on a field with similar soil conditions. One-way ANOVA with planting distance and Duncan's multiple range test at a significance level of 0.05 were used to analyze the PTO torque. The torque ratio was calculated based on the minimum torque using the average PTO torque measured under each planting condition. Results: The average torques on the PTO shaft for planting distances of 26, 35, 43, and 80 cm at a low planting depth were 11.05, 9.07, 7.04, and 3.75 Nm, respectively; the same for planting distances of 26, 35, 43, and 80 cm at a middle planting depth were 12.20, 9.86, 7.94, and 4.32 Nm, respectively. When the planting distance decreased by 43, 35, and 26 cm, the torque ratio at a low planting depth increased by 88, 142, and 195%, respectively. When the planting distance decreased by 43, 35, and 26 cm, the torque ratio at the middle planting depth increased by 84, 128, and 182%, respectively. Conclusions: PTO torque fluctuated by planting distance and depth. Moreover, the PTO torque increased for short planting distances. Therefore, farmers should determine the planting conditions of the transplanter by considering the load and durability of the machine. The results of this study provide useful information pertaining to the optimum PTO design of the transplanter considering the field load.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.6
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• pp.87-99
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• 2022

The meat consumption per person has continuously increased in recent years. However, the labor force in the domestic livestock industry has decreased due to the declining and ageing population. In order to increase productivity, the government have developed and distributed design standard of livestock houses. Presently, report showed that the adaptation rate of the developed livestock house design standard on the real farm was still low. Thus, this paper aimed to find ways to improve the utilization of the design standard through surveys. The survey was conducted on 650 farms across the country. Analysis of the result showed that in the poultry house, the unawareness of farmers to the design standard was found to be the biggest reason for not using the design standards. On the other hand, in the swine house, the previously built swine houses do not fit with the design standard. From these result, the following recommendations were suggested: 1) promotion and education are needed to enhance usage of design standard; 2) since it is impossible to make a design standard considering all the farm sites, it is important to consider the conditions of various farm site prior to enhancement of the design standard; 3) improvement factors such as reinforcing the ventilation design, reflecting animal welfare, preventing livestock diseases, and enhancing ICT devices can also be promoted.

• Journal of Practical Agriculture & Fisheries Research
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• v.13 no.1
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• pp.173-183
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• 2011

Gabensis village is one of the biggest village In the Wampar Local Level Government area within the Huon Gulf District of Morobe Province with a population of around 3,000. The major staple food is banana which is well complemented by minor staples yam, cassava, Singapore/Chinese taro and sweet potato. Apart from gardening for own consumption, the villagers engage in selling of vegetables, garden staples, cocoa beans, coconuts, timber, chicken, fish and pig meat to supplement their livelihood. Livestock like pigs and chickens are also kept for meat and for commercial purpose. Bettlenut which was once one of the main cash crops has now been overtaken by cocoa due to a disease that had attacked almost the entire bettlenut tree population in the area. Even though the Wau-Bulolo highway cuts through the village and all have access to transport infrastructure, the majority of the population still encounter problems in communication due to poor telecommunication coverage. On average most people earn not more than K50 per week due to constrains in production and marketing among others. Gabensis village has the potential to develop a tourism industry given its natural attraction of Lake Wanam. Beside there is also the natural eel farming and the fish pond at the nearby Potsie village. These natural attractions pose huge tourism potential for the community. As part of government services delivery and development, education and health issues is very much important in the community however there is lack of infrastructural development and poor service delivery especially in the area of health. However, the responsibility is on the community to organize themselves to realize that potential. A well developed agro-ecotourism investments would have positive spillover effects to the community thus contributing towards improving the livelihoods of the many farming families.

• Journal of Science and Technology Studies
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• v.6 no.2 s.12
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• pp.131-183
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• 2006

The Korean genetics and genomics reveal a firm willingness to participate in and contribute to the production of creative scientific knowledge at a world level at present, though they have short past histories of introduction from the Western counterparts and those of education for the next generations. But the Korean genetics and genomics have been developed in a fragmented and biased manner. By reconfiguring the various research projects of genomics into the Genome Project of Korea, which reflect a worldly trend in life science, but have been established in a scattered fashion in Korea, and incorporating some neglected areas of genetics, such as human genetics and theoretical and population genetics which can be reconstructed in a new way, a genetics-genomics research system can be formulated on the multi-tiered perspective of concept, knowledge, and institution, while the system being a subsystem of the national research system of life science in Korea. Innovation can be pursued in the systematic practice through a culturalist strategy. The culturalist strategy with the practice based on the research system consists of 1) intensification of fundamentalness of genetics and genomics, 2) advancement of communitarianism in geneticist-genomicist community, 3) research on the cultural bio-species along with the promotion of scientific arts and culture, and 4)formation of the Korean science studies of genetics-genomics and the diffusion of the knowledge produced. The first two strategy components are the ones that intends to bring out changes in the structural aspect of the scientist community in Korea. The third is the one that attempts to magnify the interface between the scientist community and the Korean society at large and increase its connectivity between both, while the fourth is the one that has an intentionality toward the Korean society outside of the scientist community. This culturalist strategy is intended to increase the cultural constructivity of the genetics-genomics research system in Korea.

• Journal of The Korean Society of Agricultural Engineers
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• v.60 no.5
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• pp.135-147
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• 2018

The objective of this study was to analyze the characteristics of combined 1D/2D inundation simulation of riverside farmland using the Hydrologic Engineering Center - River Analysis System (HEC-RAS). We compared and analyzed inundation simulation results between 1D and combined 1D/2D hydraulic simulation using HEC-RAS. Calibration and validation of stream stage were performed using three rainfall events. The coefficient of determination ($R^2$) and root mean square error (RMSE) between simulated and observed stream stage were 0.935 - 0.957 and 0.250 m - 0.283 m in calibration and validation, respectively. The inundation area showed no significant difference in 1D and combined 1D/2D simulation ($8.48km^2$ in 1D simulation, $8.75km^2$ in combined 1D/2D simulation). The average inundation depth by 1D simulation was 1.4 m deeper than combined 1D/2D simulation. In the lower inundation depth, the inundation area by combined 1D/2D simulation was larger than inundation area by 1D simulation. As the inundation depth increased, the inundation area by 1D simulation became wider. In the case of the 1D/2D combined simulation, low elevation areas along the river bank were inundated widely. Compared to 1D/2D combined simulation, the flood radius in some sections was longer in 1D simulation. In the 1D analysis, because the low altitude riverside farmlands are also assumed to stream, it is calculated that riverside farmlands have the same stage as the mainstream when the stream is overflowed. Therefore, the inundation area seems to be overestimated in those sections. In other regions, the inundation areas tend to be broken depending on overflow by each stream cross-section. In the case of river flooding, the overflow is expected to flow to the lower area depending on the terrain, such as the results of the combined 1D/2D simulation. It is concluded that the results of combined 1D/2D inundation simulation reflected the topographical characteristics of low-lying farmland.

• Journal of Convergence for Information Technology
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• v.8 no.6
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• pp.59-66
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• 2018

The utilized coefficient of friction (UCOF) as a ratio of the shear force to the normal force on the ground during walking is used to identify the point at which slip is likely to occur. Shoe walking will change the utilized coefficient of friction by shoe design such as sole thickness and hardness, heel shape, and outsole pattern. In this study, subjects are 21 adults (10 female, 11 male, age: $25.2{\pm}2.3yrs$, height: $165.6{\pm}7.2cm$), analysis variables were walking speed, GRF, when the UCOF is maximal, and Tangent of CoP-CoM angle, and correlation analysis with the utilized friction coefficient (UCOF). As a result, First, for the shod walking the time point which UCOF is maximum about heel strike was faster and the magnitude was larger than for barefoot walking. Second, the correlation between the tangent of CoP-CoM and UCOF of right foot was higher at the left heel striking point (UCOF2_h) which occurred in the post propulsion phase than at the right heel striking point (UCOF1_h). This suggests that the right foot UCOF is related to the braking phase of left foot( which is the propulsion phase of right foot) rather than the braking phase of right foot.

• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.4
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• pp.11-22
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• 2019

The objective of this study was to improve the cross-sectional area and height estimation method using stream width. Stream water levels should be calculated together to simulate inundation of agricultural land. However, cross-sectional survey data of small rural rivers are insufficient. The previous study has developed regression equations between the width and the cross-sectional area and between the width and the height of stream cross-section, but can not be applied to a wide range of stream widths. In this study, cross-sectional survey data of 6 streams (Doowol, Chungmi, Jiseok, Gam, Wonpyeong, and Bokha stream) were collected and divided into upstream, midstream and downstream considering the locations of cross-sections. The regression equations were estimated using the complete data. $R^2$ between the stream width and cross-sectional area was 0.96, and $R^2$ between width and height was 0.81. The regression equations were also estimated using divided data for upstream, midstream and downstream considering the locations of cross-sections. The range of $R^2$ between the stream width and cross-sectional area was 0.86 - 0.91, and the range of $R^2$ between width and height was 0.79 ? 0.92. As a result of estimating the cross-sections of 6 rivers using the regression equations, the regression equations considering the locations of cross-sections showed better performance both in the cross-sectional area and height estimation than the regression equations estimated using the complete data. Hydrologic Engineering Center - River Analysis System (HEC-RAS) was used to simulate the flood stage analysis of the estimated and the measured cross-sections for 50-year, 100-year, and 200-year frequency floods. As a result of flood stage analysis, the regression equations considering the locations of cross-sections also showed better performance than the regression equations estimated using the complete data. Future research would be needed to consider the factors affecting the cross-sectional shape such as river slope and average flow velocity. This study can be useful for inundation simulation of agricultural land adjacent to an unmeasured stream.

• Journal of Nutrition and Health
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• v.54 no.5
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• pp.547-559
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• 2021

Purpose: This study compares the snacking pattern, diet, lifestyle, and food preference of children by evaluating the most frequently eaten snacks. Methods: The survey enrolled 435 students from three elementary schools in Gyeonggi. Based on the most frequently eaten snacks, the subjects were divided into 3 groups: fruits and milk/dairy products for natural snacks (NS, n = 114); noodles, snack foods and fast foods for meal-like snacks (MS, n = 74); cookies, beverages and bread as sweet snacks (SS, n = 247). Results: Compared to the MS group, preferences of the NS group were significantly higher for jabgokbap (cooked rice with multi-grains, p < 0.05) and saengchae (seasoned raw vegetables, p < 0.01), and significantly lower for gogitwigim (deep-fried meat, p < 0.05). Taste preference of the NS group was considered to be more desirable; the taste preference of more subjects was 'sweet taste' in the SS group, 'spicy taste' in the MS group, 'salty taste' in the MS and SS groups, and 'sour taste' and 'bland taste' in the NS group than the other groups. Compared to the MS and SS groups, the NS group was determined to exercise more frequently; exercising for more than 30 minutes/day was determined to be 76.3% in the NS group and 58.1% and 57.9% in the other groups (p < 0.01). Moreover, a higher proportion of subjects in the MS group tended to answer 'not hungry' as the reason for leaving school meals, as compared to other groups (p = 0.055), thereby suggesting that inappropriate snacking habits interfere with regular meals. Conclusion: This study provides evidence that healthy snacking habits, which include natural snacks such as milk/dairy products and fruits, are important for children during the elementary school years, since these habits are associated with healthier diet, lifestyle, and food and taste preferences. These results provide basic information for developing nutritional education materials for elementary school children.

• Journal of the Korean earth science society
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• v.43 no.5
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• pp.591-603
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• 2022

The color and optical properties of seawater are determined by the interaction between dissolved organic and inorganic substances and plankton contained in it. The Ieodo - Ocean Research Institute (I-ORS), located in the East China Sea, is affected by the low salinity of the Yangtze River in the west and the Tsushima Warm Current in the south. Thus, it is a suitable site for analyzing the fluctuations in circulation and optical properties around the Korean Peninsula. In this study, seawater surrounding the I-ORS was classified according to its optical characteristics using the satellite remote reflectance observed with Moderate Resolution Imaging Spectroradiometer (MODIS)/Aqua and National Aeronautics and Space Administration (NASA) bio-Optical Marine Algorithm Dataset (NOMAD) from January 2016 to December 2020. Additionally, the variation characteristics of optical water types (OWTs) from different seasons were presented. A total of 59,532 satellite match-up data (d ≤ 10 km) collected from seawater surrounding the I-ORS were classified into 23 types using the spectral angle mapper. The OWTs appearing in relatively clear waters surrounding the I-ORS were observed to be greater than 50% of the total. The maximum OWTs frequency in summer and winter was opposite according to season. In particular, the OWTs corresponding to optically clear seawater were primarily present in the summer. However, the same OWTs were lower than overall 1% rate in winter. Considering the OWTs fluctuations in the East China Sea, the I-ORS is inferred to be located in the transition zone of seawater. This study contributes in understanding the optical characteristics of seawater and improving the accuracy of satellite ocean color variables.