• Journal of the Institute of Electronics and Information Engineers
• /
• v.50 no.6
• /
• pp.201-211
• /
• 2013

In this paper, we propose a hand tracking and gesture recognition system. Our system employs a depth capture device to obtain 3D geometric information of user's bare hand. In particular, we build a flexible tracking volume and restrict the hand tracking area, so that we can avoid diverse problems caused by conventional object detection/tracking systems. The proposed system computes running average of the hand position, and tracking volume is actively adjusted according to the statistical information that is computed on the basis of uncertainty of the user's hand motion in the 3D space. Once the position of user's hand is obtained, then the system attempts to detect stretched fingers to recognize finger gesture of the user's hand. In order to test the proposed framework, we built a NUI system using the proposed technique, and verified that our system presents very stable performance even in the case that multiple objects exist simultaneously in the crowded environment, as well as in the situation that the scene is occluded temporarily. We also verified that our system ensures running speed of 24-30 frames per second throughout the experiments.

• Journal of the Korean Institute of Telematics and Electronics S
• /
• v.35S no.8
• /
• pp.1-11
• /
• 1998

One of the desired features for the realizations of high quality Information and Telecommunication services in future is "the Sensation of Reality". This will be achieved only with the visual communication based on the 3- dimensional (3-D) moving images. The main difficulties in realizing 3-D moving image communication are that there is no developed data transmission technology for the hugh amount of data involved in 3-D images and no established technologies for 3-D image recording and displaying in real time. The currently known stereoscopic imaging technologies can only present depth, no moving parallax, so they are not effective in creating the sensation of the reality without taking eye glasses. The more effective 3-D imaging technologies for achieving the sensation of reality are those based on the multiview 3-D images which provides the object image changes as the eyes move to different directions. In this paper, a multiview 3-D imaging system composed of 8 CCD cameras in a case, a RGB(Red, Green, Blue) beam projector, and a holographic screen is introduced. In this system, the 8 view images are recorded by the 8 CCD cameras and the images are transmitted to the beam projector in sequence by a signal converter. This signal converter converts each camera signal into 3 different color signals, i.e., RGB signals, combines each color signal from the 8 cameras into a serial signal train by multiplexing and drives the corresponding color channel of the beam projector to 480Hz frame rate. The beam projector projects images to the holographic screen through a LCD shutter. The LCD shutter consists of 8 LCD strips. The image of each LCD strip, created by the holographic screen, forms as sub-viewing zone. Since the ON period and sequence of the LCD strips are synchronized with those of the camera image sampling adn the beam projector image projection, the multiview 3-D moving images are viewed at the viewing zone.

• Journal of the Korea Society of Computer and Information
• /
• v.25 no.11
• /
• pp.105-114
• /
• 2020

In this paper, we address security issues in 5G non-public networks for industrial applications. In contrast to public networks that offer mobile network services to the general public, 5G non-public networks provide 5G network services to a clearly defined user organization or groups of organizations, and they are deployed on the organization's defined premises, such as a campus or a factory. The main goal of this paper is to derive security threats and potential security requirements in the case that 5G non-public networks are built for discrete and process industries according to the four deployment models of 5G-ACIA (5G Alliance for Connected Industries and Automation). In order to clarify the scope of this paper, we express the security toolbox to be applied to 5G non-public networks in the form of the defense in depth concept. Security issues related to general 5G mobile communication services are not within the scope of this paper. We then derive the security issues to consider when applying the 5G-ACIA deployment models to the industrial domain. The security issues are divided into three categories, and they are described in the order of overview, security threats, and potential security requirements.

• Korean Journal of Environment and Ecology
• /
• v.18 no.4
• /
• pp.359-368
• /
• 2004

The purpose of this study is to examine distribution and damages of the trails of inquiry of urban natural parks. Those parks were located at south-north green corridor at Incheon being mountainous type of urban natural parks that were core area of urban ecosystem preservation to of urban natural parks that citizens recently made use of them as nature experience type of leisure and recreation place from time to time, and to supply basic material deciding on the ways to improve the trails of nature preservation type. The survey sites included Geyang Park, Baekma Park, Yaksa Park, Munhak Park and Cheongryang Park. The number of main trails was 42 at Geyang Park, 43 at Baekma Park, 9 at Yaksa Park, 28 at Munhak Park, and 22 at Cheongryang Park, and it was excessively more than optimum needed: The number of branch trails of the parks seemed to increase. The bared trail width in average of the roads was 3.5m, while maximum depth in average was 21.3cm. The trails were thought to be deteriorated rapidly without systematic maintenance. The 5th and 6th grade of the impact rating class that required restoration because of serious deterioration occupied 19.6∼78.0%. Based on the findings, the study suggested ways to improve and manage the trails of inquiry of urban natural parks that were placed at south-north green corridor at Incheon.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.30 no.2
• /
• pp.51-60
• /
• 2018

This study was conducted to observe the effects of gravity and infra-gravity wave of detached submerged breakwater in the coast of Yeongnang-dong, Sokcho, as analyzing continuous wave data by performing field observations on the front area (W0) and rear area (W1, W2). Wave transmission coefficient ($K_t$) of submerged breakwater was analyzed in two parts, short-period wave (gravity wave) and infra-gravity wave. The wave energy reduction effect was analyzed and compared with the value of the design. In case of above wave height 2.0 m at the front area (W0) of the submerged breakwater, the short-period wave height at point W1 is reduced by about 65% and the short-period wave height at point W2 is reduced by about 59%. The depth of crest of submerged breakwater conducted in a sea area differs from the design, and the wave energy reduction effect is analyzed to be smaller than the design plan. The infra-gravity waves were amplified to 2.11 and 1.71 at the W1 and W2 points, respectively, and the wave height at W2 point was smaller than that at W1 point.

• Journal of Environmental Impact Assessment
• /
• v.29 no.2
• /
• pp.132-143
• /
• 2020

The purpose of this study is to identify the accomplishments and limits of the local governments' environmental impact assessment operation system and to propose a policy plan to improve it through an analysis of the current status of the operations by local governments. As the research method, based on an understanding of the basic purpose and concept of the local government's environmental impact assessment, the current status of environmental impact assessment by major local governments such as Seoul, Jeju, Busan, Daejeon, etc. is analyzed and in-depth interviews with public officials in charge are conducted. Through the extensive discussions, the current situation and the problems are identified. The accomplishments of the local governments' operation of environmental impact assessment are: it is possible, first, to select evaluation targets and items in accordance with regional characteristics; second, to continuously strengthen the management and monitoring the evaluation result after through its own follow-up control. The limits revealed are; first, internal organization problems, which are largely due to the fact that the project approvers and the environmental impact assessment consultants are the same; second, poor cooperation system between the department of environmental impact assessment and other departments; third, lack of professionalism in the working forces; and forth, a limited pool of the skilled judges; and last, it was found that there could be frequent problems of overlapping regulation during coordinating target projects and evaluation contents.

• International Journal of Highway Engineering
• /
• v.3 no.4 s.10
• /
• pp.127-136
• /
• 2001

To increase the structural integrity of concrete box culvert good compaction by the dynamic compaction roller with bi9 capacity is as effective as good backfill materials. It is needed for effective compaction that a compaction roller closes to concrete structure with high frequency. However structural distress of the culvert could be occur due to the excessive earth pressure by great dynamic compaction load. To investigate the characteristics of Induced stress by compaction, a box culvert was constructed with changing cushion materials and compaction methods. Two types of cushion material such as tire rubber chip and EPS(Expanded Polystyrene) were used as cushion panels and they are set on the culverts before backfill construction. Laboratory test result of cushion material says that the value of dynamic elastic modulus of rubber is lesser than that of EPS. On the other hand, material damping of rubber material is greater than that of EPS. In most case, dynamic compaction rollers with 10.5 ton weights were used and vibration frequency was applied 30Hz for the great compaction energy. This paper presents the main results on the characteristics of dynamic earth pressures during compaction. The amounts of induced dynamic pressures$(\Delta\sigma\;h)$ by compaction are affected with construction condition such as compaction frequency, depth of pressure cell, distance between roller and the wall of culvert and roller direction. Based on the measured values dynamic lateral pressure on the culverts, it could be said that orthogonal direction of roller to the length of culvert is more effective to compaction efficiency than parallel direction.

• Journal of Korean Society of Transportation
• /
• v.33 no.5
• /
• pp.488-496
• /
• 2015

The main reason to install pedestrian pushbuttons is improving traffic operations. The current guideline for the installation of signal systems with pedestrian pushbuttons is car-oriented. It is difficult to clearly understand the guideline because there isn't an in-depth study to compare the pros and cons of the pedestrian- and vehicle-oriented methods in terms of waiting time. Thus, this study aims to estimate the waiting times of pedestrians and vehicles. The two delay times are compared considering the hypothetical circumstances such as geometry, pedestrian crossing time, pedestrian/vehicle counts and arrival distribution. The results show that when the pedestrian traffic volume exceeds 97 ped/h in the case of a two-lane road (one lane in each direction) the pushbutton system is effective and beneficial to pedestrians. It means that the total waiting time of pedestrians is less than the one of vehicles. Additional four scenarios are designed and tested by varying the number of lanes and design speeds. In conclusion, the pushbutton signal is more beneficial for pedestrians when the number of pedestrians is less than or equal to 85, 70, and 70 ped/h for the three-lane scenario, the four-lane with the design speed of 80km/h scenario, and the four-lane with the design speed of 100km/h, respectively.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.5 no.4
• /
• pp.86-92
• /
• 2002

The feasibility of counting number of small vessels and position in Korean waters using the panchromatic imageries derived from the IRS-1C was tested. The parameters for interpretation of satellite's imageries of small vessels were location(position), size, shape, shadow, tone, texture and pattern, height and depth, situation and association with other vessels. The position of small vessels in the sea without GCP(ground control point) was considered to be inclusive in the satellite imagery with 35 km semi-diameter, denoting rough geographical position of the vessel. The size of vessel was measured by length from stem to stern of the vessel, distinguished by following wave on the surface water. Offshore fishing vessels were separated from merchant ships by their length smaller than 100 m. The shape of vessels on panchromatic imagery of IRS-1C appeared just streamline. In case of clouds which were similar to the shape of small vessels, we were able to distinguish between vessel and cloud by shadow of cloud in the water surface. The tone of sea surface was dark black while small vessel appeared bright white. Small vessel was distinguished from the rough texture of the sea surface and the regular pattern of the waves with white capes when weather was not so good. The situation of the fishing activity was estimated by information of fishing method related to the fishing boat such as the pair trawl in the Yellow Sea.

• Journal of the Economic Geographical Society of Korea
• /
• v.21 no.1
• /
• pp.53-68
• /
• 2018

Community-based ecotourism (CBE), if well-developed can be a practical approach for promoting socio-economic well-being and sustaining ecological resources. The growth and its development worldwide especially in developing economies is a welcome development. The study aimed at assessing the Boabeng-Fiema Monkey Sanctuary in Ghana, as an example of traditional conservation system of management that has ensured greater community participation, equity, inclusiveness, and multi-level stakeholder partnership. In-depth interviews with key informants and documentary analysis of relevant peer reviewed and grey literature were the main qualitative data collection used. Results revealed that majority of the interviewees support and value the current system of traditional management. The enforcement of rules and regulations and other cultural and religious practices were discussed by key informants. Opportunities for multiple livelihood strategies as a result of the CBE is seen as critical for increasing local's acceptance and participation. The remarkable growth of the sanctuary, as well as the increase in human population, has created a shortage of land for domestic and other commercial purposes which is identified as posing a major challenge to the sustenance of the sanctuary. The study recommends diversification of livelihood opportunities presented by the presence of the sanctuary like the introduction of homestay concept, craft making- wood carving, painting, artisan shops.