• Journal of Korean Society of Forest Science
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• v.97 no.4
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• pp.398-407
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• 2008

This study is to give management state information about changes of income and net profit due to the fluctuations of chestnut prices to someone who will manage a chestnut orchard or has been managing a chestnut orchard in the market opening time. This study, hence, evaluated 133 households who manage a chestnut orchard at Jin-ju, San-cheoung in Gyeong-nam, Gu-rae in Jeon-nam, Gong-ju, Bu-yeo, and Cheoung-yang in Chung-nam. This study analyzed three scenarios by chestnut prices and by tree ages to provide informations for working expenses, production cost, income and net income to cultivators. In case of chestnut of one thousand won, the income of chestnut trees generated from nine ages and the net income is obtained from ten ages and turned into deficit from twenty-eight ages. In case of chestnut of one thousand and five hundred won, the income of chestnut trees generated from seven ages and the net income is obtained from nine ages. In case of chestnut of two thousand won, the income of chestnut trees generated from six ages and the net income is obtained seven nine ages. We calculated out labor costs and material cost and figured out management cost by tree ages. Namely two man and twenty woman are employed in harvesting 3,000 kg by hectare from ten till eighteen ages maximum harvesting seasons. Material cost is fertilizer cost, agricultural chemicals cost and seeding cost.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.6
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• pp.558-564
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• 2013

Wireless sensor networks (WSNs) contain limited energy resources and are left in open environments. Since these sensor nodes are self-operated, attacks such as sinkhole attacks are possible as they can be compromised by an adversary. The sinkhole attack may cause to change initially constructed routing paths, and capture of significant information at the compromised node. A localized encryption and authentication protocol (LEAP) has been proposed to authenticate packets and node states by using four types of keys against the sinkhole attack. Even though this novel approach can securely transmits the packets to a base station, the packets are forwarded along the constructed paths without checking the next hop node states. In this paper, we propose the next hop node selection method to cater this problem. Our proposed method evaluates the next hop node considering three factors (i.e., remaining energy level, number of shared keys, and number of filtered false packets). When the suitability criterion for next hop node selection is satisfied against a fix threshold value, the packet is forwarded to the next hop node. We aim to enhance energy efficiency and a detour of attacked areas to be effectively selected Experimental results demonstrate validity of the proposed method with up to 6% energy saving against the sinkhole attack as compared to the LEAP.

• Journal of Environmental Impact Assessment
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• v.24 no.5
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• pp.499-515
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• 2015

The purpose of this study was to understand phytosociological characteristics and changes, providing basic ecology informations based for heronries. We investigated the 25 heronries sites to have more than a hundred nests in the country. The vegetations of heronries were arranged 8 plant communities that consisted of 60 families, 129 genuses and 167 species including 17 species of exotic species. The communities of heronries were composed of high NCD (Net Contribution Degree) of plants, such as pokeberry (Phytolacca americana), japanese chaff flower (Achyranthes japonica), asiatic dayflower (Commelina communis) including diagnosis species, that was heliophilous and tolerance of eutrophic and/or acidic soil condition, and had the highest composition with the annual plants. As locational condition, they were distributed a favorite feeding place (rice field, stream etc.) inside 0.5 km radius, and located on the eastern slope of the mountain. The vegetative composition among plants in the heronries didn't have plant sociological characteristics for environmental conditions of the sites. But generally, they had trends in floristic composition like the areas of polluted soil, open canopy and disturbance.

• Journal of Gifted/Talented Education
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• v.21 no.2
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• pp.547-573
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• 2011

In this study, using a questionnaire about camp programs, we surveyed 375 gifted education institutes, including 285 classes for the gifted, 70 institutes for the gifted at education offices, and 20 institutes for the gifted at universities. The survey questionnaire consists of questions relating to camp design, camp operation, and camp introspection. The questions relating to camp operation are subdivided into questions relating to content, process, product, and learning environment of the camp. In the analysis of camp design, experience-centered camps entailing visits to research institutes, science museums, and so on showed the highest ratio. The camps were generally carried out in summer vacation as two day/one night programs. The average score of camp content was 3.72, that of camp process was 3.78, that of camp product was 3.77, and that of camp environment was 3.58. In the analysis of camp introspection, the item 'a lack of information about diverse camp activities' showed the highest difficult thing. Integrating these results, we suggest that information about diverse camp activities should be developed and supplied and the camp environment strengthen the freedom of students to select camp activities.

• Journal of dental hygiene science
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• v.13 no.3
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• pp.347-353
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• 2013

This study was conducted to provide dental hygiene students with an opportunity which let them learn and have responsibility on bioethical perception by carrying out a survey for bioethical perception by personality types targeting 519 dental hygiene students. The study results were as follows: 1. Generally, in personality types, gender affects friendliness. Also, significant difference was shown in conscientiousness by age and practical experience. From finance point of view, significant difference was shown in neuroticism, extroversion, conscientiousness and openness, however, they did not satisfy test for equality of variances. 2. Generally, in bioethical perception, gender affects embryos right to life significantly (p <0.001) and considerable difference was appeared in intrauterine insemination by age. Significant differences were shown in embryos right to life by grade and whether students have practical experiences or not was the key factor which lead considerable difference in abortion. 3. In correlation of variances for personality types and bioethical perception, only friendliness and embryos right to life had weak correlation of 0.119. 4. In personality types affecting bioethical perception, friendlier personality had strong influence on embryos right to life. From this study, it can be concluded that bioethical perception could be affected by five personality types although they are not conclusive indicators which provide all the information.

• Journal of Convergence for Information Technology
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• v.10 no.11
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• pp.47-54
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• 2020

This study proposes an NFC-based payment system that considers user convenience while expanding the existing payment method for RFID-based individual food and logistics waste equipment. In line with this trend, I proposed to apply NFC to the existing RFID-based food meter to release the food in the meantime and to address the problem of re-carrying due to card loss, card not possessed, and non-filling, and the question that could not be identified by various cumbersome procedures. NFC's function alone has been certified for its convenience, which led to its introduction and research in the period of time. Of course, we need to negotiate fees with the transportation card company, but if we see a market share related to transportation card soon, we think smooth negotiations will take place. NFC method will be expanded to all phones with iPhone NFC opening. Therefore, in the next study, we intend to apply the payment system in NFC by linking with local currency, mobile vouchers, and card companies, which are being paid as respective payment means according to the recent emergency support system for COVID-19.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.6
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• pp.187-193
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• 2015

The ICT healing platform sets a couple of goals including preventing chronic diseases and sending out early disease warnings based on personal information such as bio-signals and life habits. The 2-step open system(TOS) had a relay designed between the healing platform and the storage of personal health data. It also took into account a publish/subscribe(pub/sub) service based on large-scale connections to transmit(monitor) the data processing process in real time. In the early design of TOS pub/sub, however, the same buffers were allocated regardless of connection idling and type of message in order to encode connection messages into a deflate algorithm. Proposed in this study, the dynamic buffer allocation was performed as follows: the message transmission type of each connection was first put to queuing; each queue was extracted for its feature, computed, and converted into vector through tf-idf, then being entered into a k-means cluster and forming a cluster; connections categorized under a certain cluster would re-allocate the resources according to the resource table of the cluster; the centroid of each cluster would select a queuing pattern to represent the cluster in advance and present it as a resource reference table(encoding efficiency by the buffer sizes); and the proposed design would perform trade-off between the calculation resources and the network bandwidth for cluster and feature calculations to efficiently allocate the encoding buffer resources of TOS to the network connections, thus contributing to the increased tps(number of real-time data processing and monitoring connections per unit hour) of TOS.

• Korean Journal of Environment and Ecology
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• v.27 no.5
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• pp.571-578
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• 2013

This study generated regression models through a direct harvesting method to estimate carbon storage and uptake by Pinus densiflora and Pinus koraiensis, the major evergreen tree species in urban landscape, and established essential information to quantify carbon reduction by urban trees. Open-grown landscape tree individuals for each species were sampled reflecting various diameter sizes at a given interval. The study measured biomass for each part including the roots of sample trees to compute the total carbon storage per tree. Annual carbon uptake per tree was quantified by analyzing radial growth rates of stem samples at breast height. The study then derived a regression model easily applicable in estimating carbon storage and uptake per tree for the two species by using diameter at breast height (DBH) as an independent variable. All the regression models showed high fitness with $r^2$ values of higher than 0.98. While carbon storage and uptake by young trees tended to be greater for P. densiflora than for P. koraiensis in the same diameter sizes, those by mature trees with DBH sizes of larger than 20 cm showed results to the contrary due to a difference in growth rates. A tree of P. densiflora and P. koraiensis with DBH of 25 cm stored 115.6 kg and 130.0 kg of carbon, respectively, and annually sequestered 9.4 kg and 14.6 kg. The study has broken new grounds to overcome limitations of the past studies which quantified carbon reduction of the study species by substituting, due to a difficulty in direct cutting and root digging of landscape trees, coefficients from forest trees such as biomass expansion factors, ratios of below ground/above ground biomass, and diameter growth rates.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.7
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• pp.39-47
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• 2012

The combination of the broadband property and the wide area coverage of satellite communications enables high speed transmission. Every user in the region under the satellite beam coverage can tranceiver and one can simultaneously communicate with multiple users. For these reasons, it is one of commendable telecommunication networks for information transfer. Since the satellite communications use open channels, it is likely to cause jamming with unwanted interference signals. In the thesis, APSK (Amplitude Phase Shift Keying) is employed, which is recommended for DVB-S2 due to high-speed transmission and excellent bandwidth efficiency. For obtaining reliable communication under the jamming environments, the communication satellite transponder rests on the polyphase filter bank structure, which enables switching among the subchannels and gain control on each subchannel, resulting in effectively eliminating jamming. Furthermore, the nulling scheme, one of the various anti-jamming approaches, is investigated, in which unwanted jamming signals are eliminated in the frequency domain after passing through the analysis part of the polyphase filter bank. The performance of the nulling scheme is evaluated for tone jamming and partial band jamming in terms of BER and EVM. The simulation results indicate that the nulling scheme improve the BER and EVM performance over the case without any anti-jamming approach.

• Journal of Korea Game Society
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• v.11 no.6
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• pp.127-138
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• 2011

The creation and interchange of information through the Internet network forms online community and makes Social Network Game (SNG) as a new entertainment by grafting it onto the most popular online games. SNG means the service which amalgamates social network service (e.g., Facebook, Twitter, etc) strong points and the fun of online game. It promotes the intimacy of relation between the friends above social network service and the gaming amusement for users. The domestic SNG market is currently fast changing according to the smart environment which is quickly shifted. The existing online game field will continuously maintain a market size. SNOG will be more developed because it is competitive from the business perspective of managing cost and production cost when compares with the existing online game. In relation to Facebook, Twitter, etc. overseas SNS platform base SNOG service, the domestic competition for launching SNG is expected to heat up as NHN, Daum and SK Communication introduce open type SNS. This study examines the successful factors and strategy for domestic SNOG by studying the case of MapleStory Adventures successful possibility. The possible successful factors are combing SNS on the existing popular online game, marketing through the existing users, and solving the platform problem of a failure factor of NexonStar. This case study is expected to contribute to the domestic SNOG industry development by providing several implications for the successful factors and strategy of SNOG which will be continuously developed.