• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.42 no.4
• /
• pp.871-878
• /
• 2017

As the interest of things to the Internet increases, the market of IoT grows larger and devices and protocols related with IoT are evolving.As these IoT devices and protocols evolve, There was a problem with interoperability. As a result, market and standard of IoT are confused, and communication between objects and objects is being hindered by different platforms. Currently, various IoT platforms are being developed and interoperability with heterogeneous platforms is under study, but the protocols used on each platform are limited and designed to have no generalized structure. Therefore, in this paper, we analyze services of HTTP, CoAP, and MQTT protocols, which are typical in the Internet market, and design services that enable selective protocol communication. We also design resources that apply the RESTful API to generalize platform usage. and We implemented the platform through database modeling for quick processing and safety of the collected data. Through this process, devices communicating with different protocols can be interworked on one platform and We propose a "generalized selective protocol based Internet object data collecting platform" that can be applied to various protocols.

• Journal of the Korean Wood Science and Technology
• /
• v.32 no.2
• /
• pp.9-18
• /
• 2004

This study was carried out to find the efficient methods for preventing resin exudation from spruce board during high temperature environment service.In the dry-air oven test, in-use temperature related to resin exudation of 110℃ could be obtained by the appropriate kiln drying without any special treatment, and the in-use temperature of the radio-frequency/vacuum (RF/V)-dried boards was about 20℃ higher than that of the conventional kiln-dried boards.In the autoclave test, resin exudation was not found from any board dried in the conventional kiln and in the RF/V kiln after the low pressure steam explosion (SE) treating, while for the control resin exudations were more severe in the autoclave test above 130℃ than in the dry-air oven test. It, therefore, would be suggested that resin exudation during high temperature service condition can be prevented more effectively by super-heated steaming green boards than by high-temperature drying boards with low moisture.

• Journal of Platform Technology
• /
• v.11 no.5
• /
• pp.84-96
• /
• 2023

Network slicing refers to a technology that divides network infrastructure into multiple parts. Network slicing enables flexible network configuration while minimizing the physical resources required for network division. For this reason, network slicing technology has recently been developed and introduced in a form suitable for the 5G environment for efficient management of large-scale network environments. However, systematic analysis of network slicing research in the 5G environment has not been conducted, resulting in a lack of systematic analysis of the technology. Accordingly, in this paper, we provide insight into network slicing technology in the 5G network environment by conducting a comparative analysis of the technology. In this study's comparative analysis, 13 literatures on network slicing in the 5G environment was identified and compared and analyzed through a systematic procedure. As a result of the analysis, three network slicing technologies frequently used for 5G networks were identified: RAN (radio access network) slicing, CN (core network) slicing, and E2E (end-to-end) sliding. These technologies are mainly used for network services. It was confirmed that research is being conducted to achieve quality improvement and network isolation. It is believed that the results of this comparative analysis study can contribute to 6G technology research as a future direction and utilization plan for network slicing research.

• Korean Journal of Environment and Ecology
• /
• v.25 no.1
• /
• pp.1-9
• /
• 2011

In order to analyze the change in home ranges depending on the reproductive stage of Pipistrellus abramus, radio-tracking was carried out for a total of 9 individuals, 3 individuals each, by dividing stages into a pregnancy stage, lactation stage, and post-lactation stage from May to August 2009. For radio-telemetry, 0.38g transmitters, R2000 receivers and 3-element Yagi antennas were used. Pipistrellus abramus were captured using a double-stacked mist net and a harp-trap. Analysis of home ranges used a SHP File and ArcGIS 3.3 for GIS, and used a Kernel Home Range Method(KHR) and a Minimum Convex Polygon(MCP) Method for analysis. Home ranges at the pregnancy stage were MCP 100% $13.46{\pm}1.84ha$, MCP 95% $12.28{\pm}2.15ha$, KHR 50% $3.00{\pm}0.71ha$, and home ranges at the lactation stage were MCP 100% $8.13{\pm}0.23ha$, MCP 95% $7.73{\pm}0.63ha$, KHR 50%$1.84{\pm}1.05ha$. Home ranges at the post-lactation stage were MCP 100% $125.58{\pm}97.77ha$, MCP 95% $123.89{\pm}97.73ha$, KHR 50% $28.61{\pm}26.78ha$. As a result, home ranges of pipistrellus abramus showed a significant difference in all of the MCP 100%, MCP 95%, KHR 50% depending on reproductive stages, being largest in the post-lactation stage and smallest in the lactation stage.

• Journal of Digital Convergence
• /
• v.10 no.9
• /
• pp.375-381
• /
• 2012

If a mobile station requests a channel allocation in its mobile networks, the switching center assigns a channel to a mobile station that belongs to each base station. There are three kinds of channel allocation schemes; a fixed channel allocation, a dynamic channel allocation and a hybrid combination of these two forms. In assigning a good frequency, it is our intention to provide quality service to our customers as well as to use resources efficiently. This paper proposes methods of assigning frequencies that minimize interference between channels and that also minimize the amount of searching time involved. In this paper, we propose an algorithm to per specific equipment, regardless of the number of channels that can be used as a general-purpose system, such as base stations, control stations, central office model is proposed, the existing operators manner similar to the fixed channel allocation based statistics and assigned when the conventional method and the improved method is proposed. Different ways and compared via simulations to verify the effectiveness of the proposed approach.

• Journal of KIISE
• /
• v.44 no.9
• /
• pp.976-985
• /
• 2017

Wireless mesh network (WMN) is a promising technology for building a cost-effective and easily-deployed wireless networking infrastructure. To efficiently utilize limited radio resources in WMNs, packet transmissions (particularly, redundant packet transmissions) should be carefully managed. We therefore propose a lightweight traffic redundancy elimination (LTRE) scheme to reduce redundant packet transmissions in software-defined wireless mesh networks (SD-WMNs). In LTRE, the controller determines the optimal path of each packet to maximize the amount of traffic reduction. In addition, LTRE employs three novel techniques: 1) machine learning (ML)-based information request, 2) ID-based source routing, and 3) popularity-aware cache update. Simulation results show that LTRE can significantly reduce the traffic overhead by 18.34% to 48.89%.

• The Research Journal of the Costume Culture
• /
• v.4 no.3
• /
• pp.427-445
• /
• 1996

According as the fashion at the latter half part of the 20th century is diversified and made into high-class gradually, it is demanding the individuality of each one. Especially, since the beginning of 1980s, fashion came to represent the restoration mood in a modern style because of the popularization of post-modernism. And with this, it came to result in the reappearance of minimalism which was one of anti-culture in 1960s. In this study, this researcher grasped the appearance background, concept and structural concept of minimalism, and tried to study the influence that he minimalism had on fashion in the flow of fashion over the first half period of the 20th century. Minimalism is the fine art trend of American characteristic which quicked by the meeting of European culture and American culture, according as the new avant-grade art of Europe moved to America after World War II Minimalism which appeared, refusing the mechanisation, industrialization and mass production of America and the falsehood of consciousness and sensitivity under existing system remained obscure by the pop art which is the commercial fine art of same period, but it came to expand the domain of work possibility of modern fine art, and it became the basis of appearance of post-modernism. Minimalism has 4 kinds of structural features which are nonside nature, repetitiousness and environment nature with 3 dimensional feature which is issue nature. Minimalism is appearing in the exfcellent and future-oriented fashon of Andre Kureju t the time of 1960 well. Then science revolution and minimalism aroused the mini-revolution, and they made the compact radio in electric home appliances and the miniskirt in fashion appear. The features of minimal fashion as Retro '60' which appeared in the decedent mood with the 21st century just before on are as follows: First, the are the pursuit of concise plastic line. Second, it is the use of high tech material Third, the miniaturization in size amy be enumerated. Minimal fashion will appear s the positive confrontation from of mankind as the optimistic viewpoint about feature in the situation hat environment was destroyed and the resources were exhausted.

• Journal of Animal Environmental Science
• /
• v.12 no.2
• /
• pp.61-66
• /
• 2006

This study was carried out to investigate the relationship between the physical dimensions of ear and age for swine. The physical dimensions of ear and weight for twenty pigs were investigated on 1, 20, 40, 90, 120, and 150 days of age, respectively. The thickness of ear was measured at the upper, middle, and lower part of fore perimeter, and the middle and lower part of hind perimeter. The length of ear was measured for width and height. The thickness of ear increased rapidly from 1 day to 20 days of age, then it developed gradually after that period of time. The thickness at the lower part of fore perimeter increased most rapidly from 1 day to 20 days of age. In the length of ear, width increased gradually whereas height increased rapidly from 1 day to 90 days of age and then they almost did not. All the regression equations between the physical dimensions of ear and age were best represented by $Y=a+b\;X^{0.5}$. These results suggest that RFID has to be installed on the middle part of hind perimeter and an ID chip has to be installed on the lower part of fore perimeter.

• Tunnel and Underground Space
• /
• v.26 no.4
• /
• pp.253-265
• /
• 2016

In this study, travel time data collection of mine equipments was conducted in an underground mine using a reverse Radio Frequency IDentification (RFID) system. In the reverse RFID system, RFID readers and antennas are mounted on mine equipments, and RFID tags are attached to the underground mine gallery. Indoor experiments were performed to analyze how RFID reader transmission power levels affect tag readable area and tag recognition rates. The results showed that travel time measurement become precise when the reader transmission power was reduced, however tag recognition rates were reduced. The field experiments indicated that setting the reader transmission power to 28 dBm maintained the tag recognition rate while minimizing the tracking location error. In addition, the results revealed that the reverse RFID system can be used successfully in an underground mine to collect the travel time data of haulage trucks.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.5A
• /
• pp.536-542
• /
• 2011

For efficient utilization of spectrum resources in TV white space after DTV transition, FCC allowed usage of the spectrum for CR system. The CR system is required to cognize channel usage state for utilizing the unused spectrum in TV white space which coexists various primary and secondary systems. In the meantime, as a demand for high throughput communication had been increased recently, CR systems also consider to adopt channel bonding technology, thus spectrum sensing for channel bonded system is essentially required. In this paper, we propose a novel spectrum sensing algorithm for channel bonding system using a single channel receiver. For IEEE 802.l1af signal, the proposed algorithm provide detection probability of 90% with false alarm probability 10% at SNR -18dB for single channel system and at SNR -7dB for 8 channel bonded system, respectively. Utilizing the proposed scheme, we can detect channel bonded signal using only a single receiver, therefore system overhead for spectrum sensing can be reduced significantly.