• Korean Journal of Environmental Agriculture
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• v.26 no.1
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• pp.17-24
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• 2007

This study was carried out to classify the streams at rural watersheds by characteristics of water quality. The water quality data of 319 steams at rural watersheds in Korea were selected. Multivariate analysis was used for this purpose. The cases were divided into 5 types, and then factor analysis and cluster analysis were done. The characteristics of water quality of rural watersheds can be showed more than 40% of total water quality by first factor(organic matters and nutrients). The cluster analysis of extracted factors using factor analysis was carried out. The results showed that the Case 1 and Case 2 were classified 4 communities, Case 3 was classified 5 communities and Case 4 and 5 were classified 3 communities. Among 5 types cases, to classified the steams of rural watersheds, Case 4 - 7 water quality items - was selected as a desirable case. Many kinds of statistical analysis can be used to classify the streams of rural watersheds. Our results showed a good example to evaluate the water quality properties in Korean rural watershed.

• Archives of design research
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• v.19 no.1 s.63
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• pp.69-78
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• 2006

Nowadays, the design and development of footwear are focused on not only to protect feet against some injuries also to satisfy its personality and high-quality based on customer' subjective sensibilities. Many image source based human sensibility is needed to establish concept of footwear by new idea in design process. For satisfying costumer's and designer's disires, this study is concerned to evaluate and analyze images using human sensibility and construct image source D/B according to the result. The image evaluation performed by internet is used 1,000 Images classified into four groups(structure or architecture, transportation device, natural articles and home appliance), and 300 subjects are participated. Finally, the web D/B is constructed by the result of image evaluation that is performed statistical analysis(basic statistic, factoranalysis and multi-scaled analysis).

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.227-228
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• 2012

In contemporary architectural practice, flat sections and plan drawings are no longer a primary means of representation and communication with participants. A typical building design has an ornamental exterior wall system and a roof system that should have water-proof quality and drainage function. By comparison, distinction between exterior wall and roof are unclear in freeform buildings, and they are integrated into a concept of a building envelope. This study is to propose 3D coordinate control technology for freeform structure by CNC curved tube method in order to develop a BIM-based envelope design and construction method for freeform building. Because a much wider freeform building construction can be achieved with correct 3D data and easy-to-implement in construction field, the proposed 3D coordinate control technology is highly recommended for practical use instead of the conventional CAD system.

• Journal of Korea Society of Industrial Information Systems
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• v.7 no.5
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• pp.103-111
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• 2002

Historically, IP-based internets have been able to provide a simple best-effort delivery service to all applications they carry. Best effort treats all packets equally, with no service level, packet loss, and delay. The best-effort style has generally worked fine. But the needs of users have changed. The want to use the new real-time, multimedia, and multicasting applications. Thus, there is a strong need to be able to support a variety of traffic with a variety of quality-of-service requirements, within the TCP/IP architecture. This paper propose a framework that offers QoS in a DS domain using dynamic node setting method.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.5
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• pp.1173-1180
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• 2012

Based on Smart Phone, this study added and implemented the mobile App to the existing IT agriculture system, which system automatically controlled green house's growth environment. Because the mobile App characterfully possesses high portability, limited resource, mobile wireless network support, enterprise mobile computing support, etc., the hybrid-App should be inevitably adopted. The hybrid App can minimize resource consumption for performing related duties and also, in spite of the mobile device's limits, it can derive high performance, in which facts the system can ensure the service-based architecture's reliance and also, implements the highly sophisticated functionality as well. Through the proposed system, the study expects to contribute to improve quality of life as well as to increase farmer's income through IT-based agriculture system development.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.6
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• pp.1327-1332
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• 2011

In the mobile meteorological information services, an existing sensor system should be expanded to serve precise information. This is because of large cost problem to add the existing sensors. This thesis proposes a system architecture to construct scalable mobile meteorological information services and suggests mobile phone, sensor network, and public traffic vehicle as expended sensors. The proposed scalable sensors are compared each other and analysed the results to evaluated their strength and weakness. In this system, based on the characteristics of the sense data collected at server, a data processing methods are proposed to support efficient query processing. The proposing data processing methods have several benefits. They compress some data volume sensed by various sources on some area at some time to a logical unit. Still it could preserve same services quality.

• Journal of the Korea Society for Simulation
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• v.25 no.2
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• pp.83-92
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• 2016

Tolerances are defined as the allowable variations in the geometry and positioning of parts in a mechanical assembly for assuring its proper functionality. Tolerance analysis is the activity related to estimating the potential accumulated variation in assemblies. If the estimated variances go out of the specified ranges, it causes the quality problem. Thus, we should adjust the tolerances and this activity is called as tolerance design. In this paper, a case study on the accumulated tolerance analysis and design using Monte Carlo simulation is introduced, which is applied for developing a portable medical device. Using the simulation study, we can improve the assemblability and functionality of the product.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.2
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• pp.103-111
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• 2011

Recently, wireless mesh networks are used in various application areas. However, wireless mesh networks have limited bandwidth by the wireless transmission property, and have severe throughput degradation in multi-hop transmission in single channel wireless mesh networks. To solve this problem and support QoS, a lot of routing protocols have been proposed in mesh networks. In this paper, we propose a wireless mesh networks architecture with MPLS for QoS service. The path and traffic management from the application could be independent from QoS routing protocols by using the MPLS in wirelss mesh networks. In this paper, we design a MPLS-based mesh router with IEEE 802.11e for traffic differentiation and investigate the operation by implementation and test.

• KIEAE Journal
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• v.11 no.1
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• pp.47-55
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• 2011

Daylight is highly beneficial for improving the indoor environmental quality and reducing building energy consumption, daylighting applications are scarcely considered, especially during the Rural standard house models design process, because of lack of previous studies on elderly-light environment and complex simulation process. Therefore, daylighting process were performed using ECOTECT, which has various advantage such as easy user interface and simple simulation processes. Moreover, dynamic daylight simulation were performed using whether data. Static simulation are performed to compute static metrics such as daylight factor, whereas dynamic simulation are performed for dynamic metrics such as daylight autonomy and useful daylight illuminance using annual weather data On the basis of daylight autonomy and useful daylight illuminance analysis result, variations in annual daylight performances. A parametric and regression analysis of the window-to-wall ratio and visible transmittance showed that daylight factor, daylight autonomy increased with window-to-wall ratio and visible transmittance. It can be concluded that this new daylight criteria. useful daylight illuminance, will enable architect to obtain better fenestration design.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.9
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• pp.839-844
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• 2017

In the past few years, three-dimensional (3D) printing has been developed as a rapid prototyping (RP) technique. The fused deposition modeling (FDM)-type 3D printing is one of the most useful RP methods; however, it still has several disadvantages, such as low conductivity, heat degradation, and low surface quality. In this study, test specimens are fabricated using an FDM-type 3D printer with an ABS material. Then, the specimens undergo post-processing on submerging in acetone with various processing times. As the processing time increases, surface roughness is enhanced significantly within the first five seconds by chemical processing, following which the processing effects are reduced. Furthermore, post processing causes the ultimate strength and strain to increase slightly with increased processing time.