• Journal of Broadcast Engineering
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• v.21 no.3
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• pp.298-306
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• 2016

With the advent of Internet of Things (IoT) technology that allows the communications between things and devices over the Internet, a lot of researches on the IoT services, such as smart home or healthcare, have been progressed. In the existing machine-to-machine (M2M) communications, however, since the underlying link-layer technologies, such as Bluetooth or ZigBee, do not use the Internet Protocol (IP) communication, those technologies are not suitable to provide the IoT services. Accordingly, this paper discusses how to provide the Internet services in the M2M communication, and propose an implementation of the Constrained Application Protocol (CoAP) over 6LoWPAN for providing IoT services in the BLE networks. Based on the implementation, we compared the performance between HTTP and CoAP for IoT communications. From the experimental results, we can see that the CoAP protocol gives better performance than the HTTP protocol with two times higher throughput, 21% faster transmission time, and 22% smaller amount of generated packets.

• Survey Research
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• v.10 no.2
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• pp.45-69
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• 2009

This paper explores how multiple facets of social capital in Korea affects social conflict. The notion of social capital is composed of several elements including (1) social trust in generalized others (2) confidence in public sector fairness and the principles of democracy (3) social networks and closures and (4) community spirit and collective norms. We particularly examine how these multiple dimensions of social capital affect an individual`s tendency of social conflict orientation. The findings address the following four points. First, an individual, who trusts generalized others in a society, is less likely to be exclusive and conflict-oriented. Second, the more an individual has confidence in the efficacy of democratic processes and public sector fairness, the more (s)he is likely to be social integration oriented. When an individual, in contrast, gives strong support to a particular party (or government in power), the person is more likely to be conflict oriented. Third, an individual who mobilizes exclusive social closures to solve a problem is more likely to be conflict oriented. However, an individual who maintains a variety of inclusive social networks is more likely to be social integration oriented. Finally, the internalization of collective norms does not affect directly the tendency of individual's social conflict orientation. Increasing social capital at the individual level does not automatically guarantee societal level conflict resolutions. Rather, building extensive social closures based on strong family or hometown ties, school connections, political interests has detrimental effects on social integration and conflict resolutions. More, constructive social integration in a society requires higher level of open social networks, consistent administrative and democratic procedures, and social trust in generalized others.

• The Journal of Fisheries Business Administration
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• v.39 no.1
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• pp.87-114
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• 2008

The cultured tuna production which has suddenly expanded at the short time and the demand for it attract attention. Farming mode, distribution transactions, change of the market (domestic and international) and the price trend are reviewed from the Japan's position which is the biggest consuming country. This paper tries to describe the current status of the food system related to the cultured tuna. Japanese government began the development of the tuna culture technology in 1970. It was by the Fisheries Agency's project. Kinki University which is the large scale private university in Japan participated in the project. After that, 32 years have passed. Kinki University established the full farming of the bluefin tuna in August, 2002. On the other hand, in 1974, one Japanese private enterprise began its tuna farming business in Canada. Kinki University gave this company technical cooperation. Also, in the early stages of the 90s, as for the policy of the overseas fishery cooperation foundation, it supported the tuna farming business in Australia. It is very clear to understand that the long-term technological-development has supported the take-off scene of the tuna culture business not only in foreign countries but also in Japan. The total shipment scale of the cultured tuna expanded very much within about 10 recent years. However, the decrease of the wild tuna catch, the reinforcement of the fisheries regulation and the tuna body to dwarf are remarkable now. Under the condition as the mentioned above, Japan's tuna consumption, especially, in the market at the fatty meat of tuna of the cultured tuna is building up firm status. At present, the Mediterranean Sea coastal countries, Australia, Mexico and Japan have the tuna farming sites. Australia farms the southern bluefin tuna. The others do the bluefin tuna. About for 3 years, Japan farms the juvenile of the tuna. The global production areas are as follows. 8 coastal countries of the Mediterranean Sea; 18,000 tons (61 % of the cultured tuna quantity in foreign countries), Mexico; 4,500 ton (15%), Australia; 7,000 tons (24%). In 2003, Japan has 32 managements and 39 offices for tuna farming. In Japan, Kyushu and Okinawa district, the share shows itself as 80 % of the domestic production quantity. Especially, the share of Amami-oshima Island in Kagoshima Prefecture exceeds 60 %. Therefore, this island has the maximum production scale of Japan. The amount of supply of BT and SBT was 56,000 tons in 2004. In Abroad, the tuna farming business forms a fixed connection between the importer and the wholesaler which have their office in Japan. In the field of the capital composition, the payment in advance, transaction and the way of settlement, each maintains their fixed relation. The market conditions of the cultured tuna are supported by "the decline of price level" and "the expansion of the general public consumption segment". These lead a team merchandising, and it is supported by the fixed business connection of each. This makes the profit of each business which are on the cultured tuna distribution. However, they have competition on the power balance among them.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.1
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• pp.36-41
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• 2018

This paper presents an implementation of a millimeter-wave(W band) multiflare-angle horn antenna. The proposed antenna is a multimode dual-polarized square horn having equal E- and H-plane beamwidths and consists of a multimode generating section, a four-square-waveguide exciter, orthomode transducers, and power combiners for the sum pattern formation. The antenna structure has been designed to allow for easy fabrication and the designed antenna has been fabricated to a precision of ${\pm}0.02mm$ by layer-by-layer machining and diffusion bonding. The input reflection coefficient and the radiation pattern of the fabricated antenna have been measured using a network analyzer and a far-field test facility. Measurements show that the proposed antenna has 17.7~18.3 dBi gain, $25.2{\sim}28.5^{\circ}$ beamwidth, and an input VSWR between 1.02~1.75, within ${\pm}0.5GHz$ from the center frequency.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.624-629
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• 2018

The current study was conducted to develop a portable composite gas detector allowing the detection of both $CO_2$ and $CH_4$ gases by means of the Non Dispersive Infra-Red (NDIR) method. The gas detector is configured to radiate infrared waves using infrared lamps, where the wavelength of the infrared light is reduced due to absorption throughout the chamber, and this reduction (absorption) is detected by the absorption detector, before being converted and amplified to a 3.5V~6V electrical signal, providing as accurate a measurement as possible. The conventional singe sensor method measures the relative measurement by absorbing only specified wavelengths of infrared radiation, which in the case of gas detection leads to problems with accuracy due to the lack of a reference sensor when detecting light with a wavelength of only $4.26{\mu}m$. The dual sensor employed in this study provides a comparative measurement between the reference value derived from the wavelength of $3.91{\mu}m$, which is not influenced by other gas sources, and the measurement value derived from the wavelength of $4.26{\mu}m$, in order to reduce the errors and enhance the reliability, thereby allowing low power consumption for portable devices and multi-gas detection for both $CO_2$ and $CH_4$ gases. The portable composite gas detector developed herein provides a measurement rage of 0ppm~5,000ppm for $CO_2$ gas, and 0.5%vol for $CH_4$, which allows the determination of whether the $CO_2$ and $CH_4$ contents in indoor air are less than 1,000ppm or not. The current study established that the composite gas detector can be interlinked with firefighting appliances through portable devices or home automation, and is anticipated to be very effective in fire prevention.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.4
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• pp.593-607
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• 2013

The In-Vehicle-Networking(IVN) of modern cars is constituted by an small electronic control device called ECU. In the past, there was no way to be able to access the IVN of a driving car. so IVN has been recognized as a closed environment so there is no need to exist authentication protocol between devices which are to configure the internal network and to communicate with other devices. However, constant improvements made it possible to access the IVN in many different ways as the communication technology evolves. This possibility created a need for device authentication in IVN. HB-Family are representative authentication schemes in RFID environment which has similar restrictions to IVN. In this paper, we propose an implementation method of HB-Family for device authentication between ECU considering ECU has low computing power and the message field of CAN protocol has restricted size of 8 bytes. In order to evaluate the efficiency and availability of the authentication schemes adopted our method, we have evaluated the performance based on DSP-28335 device. Further, it was possible to improve the efficiency rate of at lest 10%, up to 36%, and we then analyze this result in various aspects of the IVN.

• The Journal of the Korea Contents Association
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• v.10 no.9
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• pp.176-189
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• 2010

This study focuses on the cultural and economic effects created by long-term TV dramas that run more than 20 years. The result of this study shows that long-lasting TV dramas have significant influence in increasing audience ratings of TV broadcasting companies. An analysis of Fuji Television's "From the Northern Country" shows that the drama's audience rating has more than doubled at the end period in comparison to that at the beginning stage. The analysis shows that long-term dramas also greatly contribute to the improvement of nation's cultural capability including contents development competence by producing media contents related professionals such as actors, actresses and dramatists. Fuji Television picked an actor and an actress for the drama and kept developing their talent and make a cultural accomplishment to produce new talents who compete with performance ability for the Japanese Entertainment Business. In addition, long lasting TV dramas appear to significantly contribute to local economy by promoting tourism industry of the areas where dramas are filmed. By introducing Hurano in Hokkaido which was the main stage of "From the Northern Country" to Japanese people for 21 years, the drama played a decisive role in building Hurano's brand power.

• Korean Journal of Remote Sensing
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• v.36 no.5_1
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• pp.749-762
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• 2020

Precipitation is closely related to various hydrometeorological phenomena, such as runoff and evapotranspiration. In Korean Peninsula, observing rainfall intensity using weather radar and rain gauge network is dominating due to their accurate, intuitive and precise detecting power. However,since these methods are not suitable at ungauged regions, rainfall detection using satellite is required. Satellite-based rainfall data has coarse spatial resolution (10 km, 25 km), and has a limited range of usage due to its reliability of data. The aim of this study is to obtain finer scale precipitation. Especially, to make the applicability of satellite higher at ungauged regions, 10 km satellite-based rainfall data was downscaled to 1 km data using MODerate Resolution Imaging Spectroradiometer (MODIS) based cloud property. Downscaled precipitation was verified in urban region, which has complex topographical and environmental characteristics. Correlation coefficient was similar in summer (+0), decreased in spring (-0.08) and autumn (-0.01), and increased in winter (+0.04) season compared to Global Precipitation Measurement (GPM) based precipitation. Downscaling without calibration using in situ data could be useful in areas where rain gauge system is not sufficient or ground observations are rarely available.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.3
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• pp.326-333
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• 2015

A tidal sandshoal, called 'Puldeung' in the Daeijackdo Marine Protected Area(DMPA), is facing erosion due to sand mining in the nearby coastal region. To monitor the morphologic change and erosion of Puldeung, a camera monitoring system was established at the top of Song-Ee Mountain in Daeijack Island. The system consists of 2 Cannon digital cameras, Eye-fi memory card/Long-Term Evolution wireless network, and solar power supply. The acquired camera images were analyzed to obtain the area of Puldeung by the following methods: geometric correction of image, identification of shoreline, areal measurement of Puldeung and its error estimation. To compare the Puldeung area with previously measured area of 1.79 km2 at tidal height of 137 cm in 2008 and of 1.59 km2 at tidal height of 148 cm in 2010, we selected images with same tidal heights. The Puldeung area was 1.37 and 1.23 km2 at the tidal height of 137 and 148 cm, respectively. The erosion at DMPA is very severe and thus it is imperative to initiate the morphodynamical study on the seasonal variation and long-term evolution of Puldeung as well as the causes and measures of Puldeung erosion.

• Information Systems Review
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• v.10 no.2
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• pp.137-158
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• 2008

Rapid development of various information technologies creates new opportunities in online and offline markets. In this changing market environment, customers have various demands on new products and services. Therefore, their power and influence on the markets grow stronger each year. Companies have paid great attention to customer relationship management. Especially, personalized product recommendation systems, which recommend products and services based on customer's private information or purchasing behaviors in stores, is an important asset to most companies. CRM is one of the important business processes where reliable information is mined from customer database. Data mining techniques such as artificial intelligence are popular tools used to extract useful information and knowledge from these customer databases. In this research, we propose a recommendation system that predicts customer's purchase intention. Then, customer's purchasing intention of specific product is predicted by using data mining techniques using receipt data set. The performance of this suggested method is compared with that of other data mining technologies.