• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2007년도 춘계학술발표대회
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• pp.1213-1216
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• 2007

본 논문에서는 IEEE 802.15.4 LR-WPAN 네트워크에서 계층화된 주소 할당방식을 통한 TDMA 방식의 비콘 스케쥴링 기법을 제안한다. 본 제안은 각 노드가 데이터를 전달할 다음 노드의 active 구간을 비콘 추적 없이도 알 수 있어 데이터 전송시에 다음 노드의 경쟁구간(Contention Access Period, CAP)에 바로 참여할 수 있는 있는 형태로 되어 있다. 또한 계층적 주소 할당 방식을 사용하므로 다중 홉(multi-hop) 센서 네트워크에서 에너지 효율적인 라우팅이 가능해진다.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2017년도 춘계학술발표대회
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• pp.315-318
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• 2017

Nowadays, Distributed Denial of Service (DDoS) attacks have gained increasing popularity and have been a major factor in a number of massive cyber-attacks. It could easily exhaust the computing and communicating resources of a victim within a short period of time. Therefore, we have to find the method to detect and prevent the DDoS attack. Recently, there have been some researches that provide the methods to resolve above problem, but it still gets some limitations such as low performance of detecting and preventing, scope of method, most of them just use on cloud server instead of network, and the reliability in the network. In this paper, we propose solutions for (1) handling multiple DDoS attacks from multiple IP address and (2) handling the suspicious attacks in the network. For the first solution, we assume that there are multiple attacks from many sources at a times, it should be handled to avoid the conflict when we setup the preventing rule to switches. In the other, there are many attacks traffic with the low volume and same destination address. Although the traffic at each node is not much, the traffic at the destination is much more. So it is hard to detect that suspicious traffic with the sampling based method at each node, our method reroute the traffic to another server and make the analysis to check it deeply.

• 한국정보통신학회논문지
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• 제17권3호
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• pp.755-761
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• 2013

무선 센서 네트워크에서 다중접근제어(Medium Access Control: MAC) 프로토콜은 센서 노드들이 필요할 때만 on 상태에 머물게 함으로 에너지를 효율적으로 사용하도록 하게한다. 본 논문에서는 에너지 수확 무선 센서 네트워크에서 우선순위에 기반을 둔 에너지 효율적인 MAC 프로토콜(EEPB-MAC)을 제안한다. 제안된 EEPB-MAC은 기존의 IEEE 802.15.4의 비콘 프레임에 우선순위 비트, 전송 노드 주소, NAV 값을 가지는 필드를 추가하여 이를 통하여 우선순위 데이터 전송을 지원한다. 데이터 전송을 원하는 전송자로부터 비콘 프레임을 수신한 수신 노드는 수신된 비콘 프레임의 우선순위 비트에 기반으로 데이터를 전송할 전송자를 선택한다. 데이터의 특성에 따라 우선순위 전송을 지원할 뿐 만 아니라, 수신 노드의 잔여 에너지 레벨에 따라 전송 주기를 조절하는 등 데이터 전송에 참여하는 노드에서의 에너지 소모를 줄인다. EEPB-MAC 프로토콜은 기존에 제안된 다른 프로토콜에 비해 우선순위가 높은 데이터에 대한 전송지연을 줄이며, 각 노드에서의 에너지 소모를 개선시켰다.

• 한국기술사회:학술대회논문집
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• 한국기술사회 1983년도 한일기술사 합동 심포지움
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• pp.71-73
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• 1983

I. History of the Gijutsushi Act revised II. The Revised Parts of the Act (1) The Revision of the Act; the Gijutsushi-in-Training newiy established 1) The Preliminary Examination was abolished. 2) The Normal Examination consists of two parts, i.e. 1st Stage Examination and 2nd Stage Examination. 3) Those who have passed the 1st Stage Examination are entitled to be Gijutsushi in Training: those who have passed the 2nd Stage Examination are entitled to be Gijutsushi. 4) The Gijutsushi-in-Training will register with the Science and Technology Agency and assist the professional business of Gijutsushi by using the title of Gijutsushi in Training. 5) Requirements for the Examinations. (a) No professional experience will be required for those who wish to apply for the 1st Stage Examination. (b) Those who wish to apply for the 2nd Stage Examination are required to have assisted Gijutsushi as Gijutsushi in Training for the period designated in the ordinance issued from the Prime Ministers' Office (7 years, probably) or mere. (c) All restrictions due to educational careers were abolished as to both kinds of Examinations. 6) Under certain conditions, the 1st Stage Examination will partially be waived. (2) The Subrogation of the Examinations The Director-General of the Science and Technology Agency is able to designate another agency to conduct, on its behalf, the affairs related to the Examinations. (3) The Subrogation of Affairs related to the Registrations The Director-General of the Science and Technology Agency is able to designate another agency to conduct the affairs related to the registration of Gijutsushi and Gijutsushi-in- Training. (4) The Symplification of Registration, etc. 1) The address will be deleted from the matters to be registered. 2) The address and the site of office will be deleted from the matters to be inserted in the Certificate of Registration.

• 한국기록관리학회지
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• 제20권3호
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• pp.1-21
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• 2020

국가기록원은 2015년부터 보존기간 30년 이상의 표준 전자문서를 중앙행정기관으로부터 이관 받고 있다. 이 과정에서 다양한 종류의 오류와 비효율이 발견되었으나, 그 오류원인을 분석하고 문제해결을 위한 연구는 없었다. 본 연구를 통하여 이관 시 발견되는 대부분의 오류가 생산단계에서 발생하는 것을 확인하고, 이를 해결하기 위한 4가지 방안을 제안한다. 첫째, 전자문서를 결재하기 전에 본문 및 첨부 파일의 결함을 체크하여 오류를 사전에 방지한다. 둘째, 결재와 동시에 전자파일 단위로 전자지문을 생성 및 관리하여 무결성을 보장한다. 셋째, 이관 및 보존 과정에 전자지문 비교·확인 및 결함체크 절차를 적용하여 자동으로 무결성 검증 및 이관 검수를 수행한다. 넷째, 기록화 대상 기준 및 무결성 보장 기술 등이 생산단계에 제대로 적용되는지 관리 및 감독한다.

• 천문학논총
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• 제33권2호
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• pp.9-19
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• 2018

We investigate the life of Lee Cheon (1376-1451) who was closely connected with astronomy during the reign of King Sejong of the Joseon dynasty. Lee Cheon is widely regarded as one of the outstanding scientists of King Sejong's period. However, his contributions to the development of the astronomy during the period have not been enlightened. Based on the historical records on the life and achievements of Lee Cheon, mainly referring to the Joseonwangjosillok (Annals of the Joseon Dynasty), we address three important points. First, Lee Cheon was a distinguished administrator who filled various government posts. Second, he was a supervising engineer in public works and metal smelting during his position in military. Third, he was a scientific technician and manufactured precision equipment such as the metal movable type sets. By virtue of these aspects, Lee Cheon was taken into confidence by King Sejong on the Ganui-dae project (i.e., manufacture various astronomical instruments and construct their platform in order to make a calendar suitable for Joseon). During the period of this project, Lee Cheon not only supervised the construction of the Ganui (simplified armillary sphere) and Ganui-dae (platform for astronomical instruments) but also participated in the production of the astronomical instruments such as Gyupyo (Gnomon) and Honcheonui (Armillary Sphere). In conclusion, we regard Lee Cheon as one of the astronomers who led a great advance in astronomy during King Sejong's era.

• International Journal of Advanced Culture Technology
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• 제10권1호
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• pp.274-283
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• 2022

Korea is facing a number difficulties arising from rising housing prices. As 'housing' takes the lion's share in personal assets, many difficulties are expected to arise from fluctuating housing prices. The purpose of this study is creating housing price prediction model to prevent such risks and induce reasonable real estate purchases. This study made many attempts for understanding real estate instability and creating appropriate housing price prediction model. This study predicted and validated housing prices by using the LSTM technique - a type of Artificial Intelligence deep learning technology. LSTM is a network in which cell state and hidden state are recursively calculated in a structure which added cell state, which is conveyor belt role, to the existing RNN's hidden state. The real sale prices of apartments in autonomous districts ranging from January 2006 to December 2019 were collected through the Ministry of Land, Infrastructure, and Transport's real sale price open system and basic apartment and commercial district information were collected through the Public Data Portal and the Seoul Metropolitan City Data. The collected real sale price data were scaled based on monthly average sale price and a total of 168 data were organized by preprocessing respective data based on address. In order to predict prices, the LSTM implementation process was conducted by setting training period as 29 months (April 2015 to August 2017), validation period as 13 months (September 2017 to September 2018), and test period as 13 months (December 2018 to December 2019) according to time series data set. As a result of this study for predicting 'prices', there have been the following results. Firstly, this study obtained 76 percent of prediction similarity. We tried to design a prediction model of real estate transaction price with the LSTM Model based on AI and Bigdata. The final prediction model was created by collecting time series data, which identified the fact that 76 percent model can be made. This validated that predicting rate of return through the LSTM method can gain reliability.

• Journal of Ecology and Environment
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• 제48권1호
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• pp.60-73
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• 2024

Background: The available information on terrestrial pest gastropods and their impact on the environment worldwide is scarce and outdated. The present study aimed to address this gap by conducting the first comprehensive survey of pest gastropods in the Nuwara Eliya District, an important vegetable growing area in the highlands of Sri Lanka. Eighty agricultural lands were surveyed over two years by establishing ten 1 m2 sampling plots per crop type in each agricultural land. Geo-coordinates, air temperature, elevation, relative humidity, daily rainfall, soil pH, species richness and abundance were recorded for rainy and non-rainy periods. The relationship between species composition and environmental variables was analyzed using multi-regression models and distribution maps. Results: Out of the 14 species recorded in agricultural lands, nine were identified as exotic pest species. Species abundance (t = 4.69, p < 0.05) and diversity was higher in the rainy period and the dominant species during this period were Bradybaena similaris (t = 2.69, p < 0.05) and Deroceras reticulatum (t = 2. 46, p < 0.05). Eggs and estivating adults were found in soil and under decaying organic matter during the non-rainy period. The exotic species showed broader preferences for the measured environmental factors and showed a wider range in distribution compared to the native species. Variation in pest gastropod composition was significantly accounted for by elevation, relative humidity, soil pH and daily rainfall. Additionally, the species richness and abundance varied across locations due to the combined effects of elevation, crop type and stage, and field type. Conclusions: The study emphasizes the importance of understanding the biology and ecology of gastropod pests to develop effective management strategies. By considering the influence of environmental factors and implementing appropriate soil management techniques, such as targeting specific habitats and crop stages, it is possible to mitigate pest populations and minimize their impact on agricultural lands. Overall, this research contributes valuable insights into the dynamics and interactions of terrestrial gastropods in agricultural ecosystems, supporting sustainable pest management practices.

• 대한치과교정학회지
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• 제38권1호
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• pp.31-40
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• 2008

최근 절대적인 고정원의 등장으로 다른 부작용 없이 구치부 압하 치료를 가능하게 하였고, 비수술적으로 개방교 합의 심미적인 치료를 가능하게 하였다. 그러나, 이러한 치료법의 장기적인 안정성에 대한 연구는 많이 부족한 실정이다. 이에 본 연구에서는 miniscrew implant 를 이용하여 상악 구치를 압하시켜 치료한 성인 개방교합 환자 11명(남자 1명, 여자 10명) 을 대상으로 치료 전후, 그리고 유지기의 골격성, 치아 치조성 변화를 측모 두부 방사선사진을 이용하여 평가하였으며 계측치의 치료 전후 변화량간의 상관관계와 치료에 의한 변화량과 재발량과의 상관관계를 규명하여 상악구치의 압하를 통해서 개방교합을 치료할 때에 안정성을 평가하였다. 그 결과로 상악 구치는 2.22 mm 압하 (p < 0.001) 가 일어났고, 평균 17.4 개월 유지 후 0.23 mm 의 정출 (p = 0.359) 이 나타났으며, 재발율은 10.36%로 나타났다. 전치부의 수직피개는 평균 5.47 mm 의 증가 (p < 0.01) 가 나타났고 평균 17.4 개월 유지 후 0.99 mm의 감소 (p < 0.05) 가 나타나서, 재발량은 18.10%로 계산되었다. 치료 전후 수치 변화량의 상관분석을 통해 상악 구치 압하량과 하악 평면각 변화량이 상관관계 (p < 0.05) 가 있었다. 치료 전의 개방교합량, 하악 평면각, 전하안면고 경과 치료 후의 수직피개 재발량과는 상관관계가 없었다. 상악 구치 압하량과 수직피개 개선량에서 치료에 의한 변화량과 재발량이 통계적으로 유의한 상관관계를 보였고, 이를 토대로 재발량을 예측할 수 있었다. 이상의 결과를 통하여 성인 개방교합 환자에서 miniscrew implant를 이용한 상악구치부의 압하는 비수술, 심미적 접근방법으로 효율적이고 안정적인 치료방법으로 유용하게 사용할 수 있을 것으로 생각된다.

• 한국대기환경학회지
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• 제33권3호
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• pp.205-216
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• 2017

Carbonaceous aerosols such as the equivalent black carbon (eBC), the elemental carbon (EC) and the organic carbon (OC) were monitored at the Seoul Olympic Park site ($37.521^{\circ}N$, $127.124^{\circ}E$) during the KORUS-AQ 2016 campaign using a Multi Angle Absorption Photometer (MAAP) and an OCEC Analyzer. Averaged mass concentrations of eBC, EC and OC were presented as $2.46{\pm}1.52{\mu}g/m^3$, $1.01{\pm}0.60{\mu}g/m^3$ and $4.85{\pm}2.60{\mu}g/m^3$, respectively. OC/EC ratio and mass absorption cross-section (MAC) of light absorbing aerosols were calculated as 2.32 and $14.8m^2/g$, respectively. Diesel OC concentrations were estimated from a source profile of diesel vehicles as well. eBC mass concentrations measured from May $26^{th}$ to May $27^{th}$, 2016 showed 40% higher than averaged eBC mass concentrations during campaign period. $PM_{2.5}$ concentrations measured in this period were also higher than average $PM_{2.5}$ concentrations. High eBC concentrations were observed from May $29^{th}$ to May $31^{st}$, 2016 and from June $9^{th}$ to June $11^{th}$, 2016, possibly due to morning rush hour and the effect of temperature inversion at night. Diurnal variations of eBC, EC and Diesel OC showed a typical pattern of metropolitan area. In the weekend, however, diurnal variations of eBC, EC and Diesel OC mass concentrations were different from those measured in the weekday. It is expected that this study can help to understand the relationship between carbonaceous aerosols in a metropolitan area.