• Title/Summary/Keyword: Extremely low frequency

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A study on vulnerability analysis and incident response methodology based on the penetration test of the power plant's main control systems (발전소 주제어시스템 모의해킹을 통한 취약점 분석 및 침해사고 대응기법 연구)

  • Ko, Ho-Jun;Kim, Huy-Kang
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.24 no.2
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    • pp.295-310
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    • 2014
  • DCS (Distributed Control System), the main control system of power plants, is an automated system for enhancing operational efficiency by monitoring, tuning and real-time operation. DCS is becoming more intelligent and open systems as Information technology are evolving. In addition, there are a large amount of investment to enable proactive facility management, maintenance and risk management through the predictive diagnostics. However, new upcoming weaponized malware, such as Stuxnet designed for disrupting industrial control system(ICS), become new threat to the main control system of the power plant. Even though these systems are not connected with any other outside network. The main control systems used in the power plant usually have been used for more than 10 years. Also, this system requires the extremely high availability (rapid recovery and low failure frequency). Therefore, installing updates including security patches is not easy. Even more, in some cases, installing security updates can break the warranty by the vendor's policy. If DCS is exposed a potential vulnerability, serious concerns are to be expected. In this paper, we conduct the penetration test by using NESSUS, a general-purpose vulnerability scanner under the simulated environment configured with the Ovation version 1.5. From this result, we suggest a log analysis method to detect the security infringement and react the incident effectively.

Integrated Photonic Microwave Bandpass Filter Incorporating a Polymer Microring Resonator (폴리머 마이크로링 공진기를 이용한 광학적 마이크로웨이브 대역통과 필터)

  • Chin, Won-Jun;Kim, Do-Hwan;Song, Ju-Han;Lee, Sang-Shin
    • Korean Journal of Optics and Photonics
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    • v.16 no.5
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    • pp.469-475
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    • 2005
  • An integrated photonic microwave bandpass filter has been proposed and demonstrated incorporating a coherently coupled microring resonator in low-loss polymers. The proposed device may feature compact site, simple structure, tuning via the thermooptic and electrooptic effect, and flexible integration with other electrical and optical devices. The resonator was designed to have an extremely small bandwidth so that it could be used to selectively pass the optical signal carrying the microwave signal to attain efficient bandpass filtering. We made and tested two resonators with a single ring and double rings, and performed a theoretical fitting of their measured transfer curves to predict the performance of the microwave filters based on them precisely. It was found that as the number of the rings used for the resonator increases, the bandwidth gets smaller, the rolloff sharper, and the band rejection higher. Finally our filter exhibited the center frequency of 10GHz, the 3-dB bandwidth of 1.0GHz, the corresponding quality (Q) factor of 10, and the rejection outside of the passband of more than 25dB.

Occurrence of Regalecus russellii off the Coast of Gangwon-do, Korea and Coastal Environment (강원도 속초 연안에서 산갈치(Regalecus russellii) 출현과 연안환경)

  • Jong-Won Park;Soon-Man Kwon;Pyo-Il Han;Chung Il Lee
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.5
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    • pp.520-524
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    • 2023
  • Regalecus russellii, which spends most of its life in the deep sea, occasionally appears in coastal waters. However, the reasons for its appearance remain unclear. In Korea, R. russellii mainly appears along the eastern coastal waters, and most of them are caught in fishing gear, such as gill nets, or are stranded on the shore; nevertheless, the frequency of appearance is extremely low. Even if found, this species is often identified to be morphologically similar to Trachipterus ishikawae, and comprehensive analysis to identify the species through sample collection is limited. Consequently, information on the biological characteristics of R. russellii appearing in the coastal waters of Korea is scarce. Herein, the anatomical characteristics of R. russellii caught in a gill net off the Gangwon-do coast on March 14, 2023, were analyzed, and coastal water temperature was measured using an ocean buoy. Our results showed that the individual was male, its total length was 320 cm, body weight was 27.52 kg, body length was 26.62 cm, gonad weight was 619.45 g, and liver weight was 218.71 g. The stomach was full of euphausiids. The water temperature changed drastically at 15-30 m roughly a week before the R. russellii individual was caught, and the subsurface water temperature was lower than 10 ℃. Our findings provide baseline data to understand the ecological characteristics of R. russellii appearing along the eastern coast of the Korea.

Birth Statistics and Mortality Rates for Neonatal Intensive Care Units in Korea during 2007: Collective Results from 57 Hospitals (2007년 한국의 전국 57개 종합병원에서 조사한 신생아 출생 및 신생아중환자실 사망률 통계보고)

  • Hahn, Won-Ho;Chang, Ji-Young;Bae, Chong-Woo
    • Neonatal Medicine
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    • v.16 no.1
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    • pp.36-46
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    • 2009
  • Purpose: To evaluate the neonatal statistics on a national basis, data for birth characteristics and neonatal mortality were collected and analyzed from 57 hospitals in Korea. Methods: Questionnaires were distributed to determine the characteristics of neonatal births and mortality rates in 57 hospitals in Korea during 2007. We analyzed the characteristics of all inborn births and hospitalized neonates in the neonatal care units (NICUs) and compared the results with published Korean data from 1996 and 2002. Results: A total of 40,433 inborn live births were reported from the 57 hospitals during 2007. Pre-term, term, and post-term births comprised 24.2%, 75.6%, and 0.2% of the neonates, respectively. Low birth weight infants (LBWIs), very low birth weight infants (VLBWIs), and extremely low birth weight infants (ELBWIs) made up 22.0%, 4.6%, and 1.7% of the neonates, respectively. A total of 21,957 (collected by gestational period) and 21,356 (collected by birth weight) neonates were hospitalized in the 57 NICUs. Pre-term, term, and post-term neonates comprised 39.8%, 59.8%, and 0.4% of the neonates, respectively. LBWIs, VLBWIs, and ELBWIs made up 37.3%, 9.5%, and 3.3% of the neonates, respectively. Pre-term, term, and post-term neonates had mortality rates of 4.5%, 0.7%, and 3.7%, respectively, while the mortality rates of LBWIs, VLBWIs, and ELBWIs were 4.7%, 15.3%, and 32.2%, respectively. In comparison with prematurity data from 1996 and 2002, LBWIs, and ELBWIs had a marked increase in birth frequency and a decreased mortality rate in Korea during 2007. Conclusion: The number of live births and the survival rate of pre-term neonates, especially VLBWIs and ELBWIs, are increasing. Even though the outcomes of neonatal care are improving, further efforts to manage these premature infants are needed.

Comparison of neonatal outcomes between the spontaneous and in vitro fertilization twin pregnancies (인공수정 및 자연수정으로 태어난 쌍생아간 임상 양상 비교)

  • Kim, Hee Moon;Lee, Jeong Won;Shin, Seon Hee;Kim, Sung Koo;Sung, Tae Jung
    • Clinical and Experimental Pediatrics
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    • v.50 no.8
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    • pp.740-745
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    • 2007
  • Purpose : There is a dominant opinion that in vitro fertilization (IVF) leads to an increased incidence of twins, low birth weight (LBW) infants, prematurity and mortality. On the other hand, technical development of IVF and improvement of neonatal intensive care have increased the survival rate of neonates. The purpose of this study was to verify the tendency by comparing the clinical aspects of IVF and spontaneously conceived twins, and to establish methods to increase the survival rate of neonates after IVF. Methods : Retrospective reviews were performed on all twin infants who were admitted to the nursery and NICU at Kangnam Sacred Heart Hospital, Hallym University from January 1, 2000 to December 31, 2006. Medical records of IVF twins (study group, n=92) and spontaneously conceived twins (control group, n=265) were analyzed and compared. Neonatal outcomes and complications, as well as obstetric outcomes, were analyzed and compared. Results : Mean gestational age and birth weight of the study group ($34.6{\pm}3.5$ weeks, $2,203.9{\pm}617.2g$) were considerably lower than those of the control group ($36.3{\pm}2.4$ weeks, $2,367.0{\pm}517.9g$). The frequency of prematurity less than 37 weeks (68.5% vs 51.3%) and extremely LBW (15.2% vs 6.4%) were also significantly higher in the study group. Other neonatal outcomes were all insignificant. The obstetric characteristics, maternal age ($32.6{\pm}3.3$ years vs $30.3{\pm}3.9$ years) and the frequency of cesarean delivery(95.7% vs 79.9%) were significantly higher in the study group. Other obstetric outcomes were insignificant except for the frequency of incompetent internal os of cervix (36.2% vs 3.6%) and cerclage operation (38.3% vs 4.3%). Conclusion : Based on the above results, clinical outcomes of twin infants will be further improved by careful attention and thorough antenatal care of the IVF twins.

Stability of Human Centromeric Alphoid DNA Repeat during Propagation in Recombination-Deficient Yeast Strains (효모의 재조합 변이주를 이용한 인간 Centromeric Alphoid DNA Repeat의 안정성에 관한 연구)

  • Kim, Kwang-Sup;Shin, Young-Sun;Lee, Sang-Yeop;Ahn, Eun-Kyung;Do, Eun-Ju;Park, In-Ho;Leem, Sun-Hee;SunWoo, Yang-Il
    • Korean Journal of Microbiology
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    • v.43 no.4
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    • pp.243-249
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    • 2007
  • The centromere is a highly differentiated structure of the chromosome that fulfills a multitude of essential mitotic and meiotic functions. Alphoid DNA (${\alpha}$-satellite) is the most abundant family of repeated DNA found at the centromere of all human chromosomes, and chromosomes of primates in general. The most important parts in the development of Human Artificial Chromosomes (HACs), are the isolation and maintenance of stability of centromeric region. For isolation of this region, we could use the targeting hook with alphoid DNA repeat and cloned by Transformation-Associated Recombination (TAR) cloning technique in yeast Saccharomyces cerevisiae. The method includes rolling-circle amplification (RCA) of repeats in vitro to 5 kb-length and elongation of the RCA products by homologous recombination in yeast. Four types of $35\;kb{\sim}50\;kb$ of centromeric DNA repeat arrays (2, 4, 5, 6 mer) are used to examine the stability of repeats in homologous recombination mutant strains (rad51, rad52, and rad54). Following the transformation into wild type, rad51 and rad54 mutant strains, there were frequent changes in inserted size. A rad52 mutant strain showed extremely low transformation frequency, but increased stability of centromeric DNA repeat arrays at least 3 times higher than other strains. Based on these results, the incidence of large mutations could be reduced using a rad52 mutant strain in maintenance of centromeric DNA repeat arrays. This genetic method may use more general application in the maintenance of tandem repeats in construction of HAC.

Comparison of lunch quality through home meals, institutional meals, and eating-out in Chinese adults: analysis of the data from the 2011 China Health and Nutrition Survey (중국 성인의 가정식, 급식, 외식을 통한 점심식사의 질 비교 : 2011년도 중국국민건강 영양조사 자료를 이용하여)

  • Jin, Juntai;Lee, Youngmi;Park, Haeryun;Song, Kyunghee;Chang, Yunhee
    • Journal of Nutrition and Health
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    • v.52 no.6
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    • pp.618-627
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    • 2019
  • Purpose: This study evaluated the dietary quality of lunches consumed through home meals, institutional meals, and eating-out at restaurants in Chinese adults. Methods: The total of 3,708 people (aged 20 ~ 64) were selected from the data of the 2011 China Health and Nutrition Survey and divided into three groups: the home (HM, 2,845 people), institutional (IM, 579 people), and eating-out (EO, 284 people) meal groups. Dietary intakes of eight food groups, the frequency of eating certain foods, food group intake pattern, dietary diversity and the variety score of lunches were analyzed. Results: The meat intake of IM and EO were higher than that of HM (p < 0.05), and the vegetable intake was the highest in HM, followed by IM and EO (p < 0.05). The intake of fruit and milk·dairy products were extremely low in all the groups. Compared with 1/3 daily recommended intake, the meat intake was above the standard in all the groups and the vegetable intake was insufficient only in EO. The most frequently consumed food in all the groups was rice, followed by pork. The relatively desirable food group pattern, "grain + meat + vegetable", was highest in IM (66.0%) and lowest in EO (48.2%). The "grain + vegetable" pattern in HM and the "grain + meat" pattern in EO were relatively higher than that in the other groups. The dietary diversity score (p < 0.001) and dietary variety score (p < 0.001) were significantly higher in IM than that in the HM or EO. Conclusion: The lunches of Chinese adults had common problems in excess meat intake and a severe lack of fruit and milk·dairy products. Even institutional meals were not ideal as single meals for Chinese adults, although they were better in food diversity. Customized dietary educational programs based on balanced meal plans need to be established, especially for those Chinese people having lunch at home or eating out. In addition, a systematic food service program should be developed and firmly implemented.

A Study on Knowledge Entity Extraction Method for Individual Stocks Based on Neural Tensor Network (뉴럴 텐서 네트워크 기반 주식 개별종목 지식개체명 추출 방법에 관한 연구)

  • Yang, Yunseok;Lee, Hyun Jun;Oh, Kyong Joo
    • Journal of Intelligence and Information Systems
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    • v.25 no.2
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    • pp.25-38
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    • 2019
  • Selecting high-quality information that meets the interests and needs of users among the overflowing contents is becoming more important as the generation continues. In the flood of information, efforts to reflect the intention of the user in the search result better are being tried, rather than recognizing the information request as a simple string. Also, large IT companies such as Google and Microsoft focus on developing knowledge-based technologies including search engines which provide users with satisfaction and convenience. Especially, the finance is one of the fields expected to have the usefulness and potential of text data analysis because it's constantly generating new information, and the earlier the information is, the more valuable it is. Automatic knowledge extraction can be effective in areas where information flow is vast, such as financial sector, and new information continues to emerge. However, there are several practical difficulties faced by automatic knowledge extraction. First, there are difficulties in making corpus from different fields with same algorithm, and it is difficult to extract good quality triple. Second, it becomes more difficult to produce labeled text data by people if the extent and scope of knowledge increases and patterns are constantly updated. Third, performance evaluation is difficult due to the characteristics of unsupervised learning. Finally, problem definition for automatic knowledge extraction is not easy because of ambiguous conceptual characteristics of knowledge. So, in order to overcome limits described above and improve the semantic performance of stock-related information searching, this study attempts to extract the knowledge entity by using neural tensor network and evaluate the performance of them. Different from other references, the purpose of this study is to extract knowledge entity which is related to individual stock items. Various but relatively simple data processing methods are applied in the presented model to solve the problems of previous researches and to enhance the effectiveness of the model. From these processes, this study has the following three significances. First, A practical and simple automatic knowledge extraction method that can be applied. Second, the possibility of performance evaluation is presented through simple problem definition. Finally, the expressiveness of the knowledge increased by generating input data on a sentence basis without complex morphological analysis. The results of the empirical analysis and objective performance evaluation method are also presented. The empirical study to confirm the usefulness of the presented model, experts' reports about individual 30 stocks which are top 30 items based on frequency of publication from May 30, 2017 to May 21, 2018 are used. the total number of reports are 5,600, and 3,074 reports, which accounts about 55% of the total, is designated as a training set, and other 45% of reports are designated as a testing set. Before constructing the model, all reports of a training set are classified by stocks, and their entities are extracted using named entity recognition tool which is the KKMA. for each stocks, top 100 entities based on appearance frequency are selected, and become vectorized using one-hot encoding. After that, by using neural tensor network, the same number of score functions as stocks are trained. Thus, if a new entity from a testing set appears, we can try to calculate the score by putting it into every single score function, and the stock of the function with the highest score is predicted as the related item with the entity. To evaluate presented models, we confirm prediction power and determining whether the score functions are well constructed by calculating hit ratio for all reports of testing set. As a result of the empirical study, the presented model shows 69.3% hit accuracy for testing set which consists of 2,526 reports. this hit ratio is meaningfully high despite of some constraints for conducting research. Looking at the prediction performance of the model for each stocks, only 3 stocks, which are LG ELECTRONICS, KiaMtr, and Mando, show extremely low performance than average. this result maybe due to the interference effect with other similar items and generation of new knowledge. In this paper, we propose a methodology to find out key entities or their combinations which are necessary to search related information in accordance with the user's investment intention. Graph data is generated by using only the named entity recognition tool and applied to the neural tensor network without learning corpus or word vectors for the field. From the empirical test, we confirm the effectiveness of the presented model as described above. However, there also exist some limits and things to complement. Representatively, the phenomenon that the model performance is especially bad for only some stocks shows the need for further researches. Finally, through the empirical study, we confirmed that the learning method presented in this study can be used for the purpose of matching the new text information semantically with the related stocks.