• Journal of KIISE:Computing Practices and Letters
• /
• v.13 no.5
• /
• pp.293-299
• /
• 2007

Intelligent pipeline inspection gauges (PIGs) are inspection vehicles that move along within a (gas or oil) pipeline and acquire signals (also called sensor data) from their surrounding rings of sensors. By analyzing the signals captured in intelligent PIGs, we can detect pipeline defects, such as holes and curvatures and other potential causes of gas explosions. There are two major data access patterns apparent when an analyzer accesses the pipeline signal data. The first is a sequential pattern where an analyst reads the sensor data one time only in a sequential fashion. The second is the repetitive pattern where an analyzer repeatedly reads the signal data within a fixed range; this is the dominant pattern in analyzing the signal data. The existing PIG software reads signal data directly from the server at every user#s request, requiring network transfer and disk access cost. It works well only for the sequential pattern, but not for the more dominant repetitive pattern. This problem becomes very serious in a client/server environment where several analysts analyze the signal data concurrently. To tackle this problem, we devise a fast in-memory cache manager, called T-Cache, by considering pipeline sensor data as multiple time-series data and by efficiently caching the time-series data at T-Cache. To the best of the authors# knowledge, this is the first research on caching pipeline signals on the client-side. We propose a new concept of the signal cache line as a caching unit, which is a set of time-series signal data for a fixed distance. We also provide the various data structures including smart cursors and algorithms used in T-Cache. Experimental results show that T-Cache performs much better for the repetitive pattern in terms of disk I/Os and the elapsed time. Even with the sequential pattern, T-Cache shows almost the same performance as a system that does not use any caching, indicating the caching overhead in T-Cache is negligible.

• Journal of Applied Biological Chemistry
• /
• v.57 no.1
• /
• pp.65-72
• /
• 2014

Biochar (BC) from biomass pyrolysis is a carbonaceous material that has been used to remove various contaminants in the environment. The eliminatory action for burcucumber (Sicyos angulatus L.) as an invasive plant is being consistently carried out because of its harmfulness and ecosystem disturbance. In this study, burcucumber biomass was converted into BCs at different pyrolysis temperatures of 300 and $700^{\circ}C$ under a limited oxygen condition. Produced BCs were characterized and investigated to ensure its efficiency on antibiotics' removal in water. The adsorption experiment was performed using two different types of antibiotics, tetracycline (TC) and sulfamethazine (SMZ). For the BC pyrolyzed at a high temperature ($700^{\circ}C$), the values of pH, electrical conductivity, and the contents of ash and carbon increased whereas the yield, mobile matter, molar ratios of H/C and O/C, and functional groups decreased. Results showed that the efficiency of BCs on antibiotics' removal increased as pyrolysis temperature increased from 300 to $700^{\circ}C$ (38 to 99% for TC and 6 to 35% for SMZ). The reaction of ${\pi}-{\pi}$ EDA (electron-donor-acceptor) might be involved in antibiotics' adsorption to BCs. BC has potential to be a superior antibiotics' adsorbent with environmental benefit by recycling of waste/invasive biomass.

• Journal of Korean Society of Environmental Engineers
• /
• v.28 no.8
• /
• pp.866-871
• /
• 2006

The nutrient recovery in phosphate crystallization process was investigated by using laboratory scale uptlow reactors, adopting sequencing batch type configuration. The industrial waste lime was used as potential cation source with magnesium salt($MgCl_2$) as control. The research was focused on its successful application in a novel integrated sludge treatment process, which is comprised of a high performance fermenter followed by a crystallization reactor. In the struvite precipitation test using synthetic wastewater first, which has the similar characteristics with the real fermentation effluent, the considerable nutrient removal(about 60%) in both ammonia and phosphate was observed within $0.5{\sim}1$ hr of retention time. The results also revealed that a minor amount(<5%) of ammonia stripping naturally occurred due to the alkaline(pH 9) characteristic in feed substrate. Stripping of $CO_2$ by air did not increase the struvite precipitation rate but it led to increased ammonia removal. In the second experiment using the fermentation effluent, the optimal dosage of magnesium salt for struvite precipitation was 0.86 g Mg $g^{-1}$ P, similar to the mass ratio of the struvite. The optimal dosage of waste lime was 0.3 g $L^{-1}$, resulting in 80% of $NH_4-N$ and 41% of $PO_4-P$ removal, at about 3 hrs of retention time. In the microscopic analysis, amorphous crystals were mainly observed in the settled solids with waste lime but prism-like crystals were observed with magnesium salt. Based on mass balance analysis for an integrated sludge treatment process(fermenter followed by crystallization reactor) for full-scale application(treatment capacity Q=158,880 $m^3\;d^{-1}$), nutrient recycle loading from the crystallization reactor effluent to the main liquid stream would be significantly reduced(0.13 g N and 0.19 g P per $m^3$ of wastewater, respectively). The results of the experiment reveal therefore that the reuse of waste lime, already an industrial waste, in a nutrient recovery system has various advantages such as higher economical benefits and sustainable treatment of the industrial waste.

• Proceedings of the Korean Professional Engineer Association Conference
• /
• 1995.12b
• /
• pp.30-48
• /
• 1995

서울시는 국가의 수도로서 이제 6n년의 역사를 맞이하였다. 뛰어난 산수와 자연 경관을 가진 서울시의 자연은 근세이후 도시의 발전에 따른 점차적으로 훼손되어 왔으며, 특히 1960년대 이후의 도시성장기에 시행된 개발 위주의 도시 정책은 공원 녹지의 잠식을 가속화시켜 본래의 자연은 양적, 질적 측면에 많은 피해가 발생되었다. 또한 도시 정책의 부분으로서 공원 녹지 정책은 개발 위주의 도시 정책에 밀려 제기능을 발휘 할 수 없었으며, 정책에 있어서도 목표와 미래 방향에 대한 뚜렷한 비전을 제시하지 못하였다. 현재 공원 녹지와 관련된 정책 환경을 볼 때, 각종의 도시개발 사업, 지방 자치제 시행에 따를 도시의 난 개발은 부족한 공원녹지를 더욱 잠식하는 위협요소가 되고 있으며, 토지수요에 대한 공급의 한계 상황에 직면해 있는 시점에서 개발론자 들은 공원 녹지를 개발의 주요대상으로 인식하는 자세를 견지하고 있다. 그러나 최근 들어 지구 환경의 문제의 대두, 환경에 대한 시민의 관심, 정책 집행자들의 환경 보전과 관리의 움직임이 나타나기 시작하고 있어 서울시의 공원 녹지의 미래 전망을 밝게 해주는 긍정적인 요소가 되고 있다. 2000년대를 바라본 현시점에서 도시의 기간 요소로서 공원 녹지는 단지 존재만의 가치가 아니라 적정한 기능을 부여하고 이용의 활성화를 통한 공원 녹지의 새로운 탄생이 요구되고 있다. 이것은 공원 녹지정책 측면에서 공원 녹지의 양적 측면에서의 풍요로움과 질적 측면에서의 기능성의 회복과 도시 구성적 측면에서의 공원 녹지의 네트워크의 구성이라는 3가지의 정책 이슈를 제기한다. 양적 측면에서 녹의 풍요로움을 확보하기 위해서는 기존의 공급 지표 위주의 정책보다는 공원 녹지의 총량적인 관리 체제를 통한 전 도시적 차원의 공원녹지 관리 시스템이 필요하며, 공원 녹지로서 잠재 가치를 가지고 있는 새로운 유형의 공원 녹지의 조성과 각종 개발사업에 대한 공원 녹지의 잠식 방지를 위한 명확한 사회적인 공감대의 형성이 요구된다. 질적 측면에서는 공원 녹지의 기능성의 회복이라는 측면과 시대에 부합되는 새로운 기능 및 가치의 부여가 필요하며, 이를 위해서는 공원의 매력, 공원의 시설기능 증진, 녹지의 질의 향상 및 녹지 가치의 증진에 대한 다양한 시책이 요구된다. 구성적 측면에서는 공원녹지의 개별적 존재보다는 공원 녹지를 상호간 유기적인 계통을 확보하여 공원 녹지의 네트워크를 형성하여 도시 속의 산재된 고립된 섬으로서의 공원 녹지가 아닌 시민생활에 늘 가까이 있는 생활 속의 공원녹지로 재편되어야 한다. 이러한 정책의 의제는 양적 측면에서 보전(CONSERVATION)과 창출(CREATION), 질적 측면에서 쇄신(RENOVATION)과 복구(RESTORATION), 그리고 구성적 측면에서 공원 녹지의 연결(CONNECTION)과 시민 참여에 의한 운동(MOVEMENT)이라는 정책 개념의 구현을 통해 가능하다. 이러한 정책 개념과 의제를 가지고 서울시 공원 녹지 정책을 구체화시키기 위해서 푸르름의 새로운 탄생이라는 기치 아래 풍요로운 서울, 사랑 받는 공원, 생활 속의 녹지의 3대 목표, 공원 녹지의 보전, 잠재 공원 녹지의 창출, 공원의 활성화, 녹지의 복구, 경관 보전 및 복구, 공원 녹지의 네트워크, 도시 녹화의 7대 과제를 설정하고 미시설 공원 녹지 집행, 개발 사업시 공원 녹지의 확보, 환경 녹지의 총량 보호 관리, 도시 소공원 개발, 역사 문화 공원 조성, 하천 공간 복원, 공원 시설 기능 개선, 이용 프로그램 개발, 공원 관리 개선, 환경 피해 녹지의 회복, 도시 환경 림 조성, 녹지 기능 증진, 도시 자연 경관 보전, 공원 녹지체계 구성, 공원 녹지 공급 균형, 주변 환경 녹화, 가로 녹화의 17개 시책을 제안하였다. 이러한 정책사업의 원활한 추진을 위해서는 기존의 관주도의 일방적인 공원 녹지 행정이 아닌 시민의 참여를 통한 시민이 함께 하는 정 책 사업의 추진이 요구되며, 특히 민간 부문의 적극적 인 참여를 유도하기 위한 방안이 동시 에 강구되어야 한다. 또한 공공에서는 정 책 집행을 위한 조직과 행정의 개편, 예산의 확보 방안을 적극적으로 검토해야 한다. 현재 서울시는 지방자치제 시행에 따라 시 행정에 있어 많은 변화가 예고되고 있으며, 공원 녹지는 새로운 환경 변화에 부합되는 적절한 도시요소가 될 것으로 추정된다. 서울시 하천 복개의 금지, 하천공간의 복원에 대한 움직임, 환경 녹지 복구를 위한 사업의 시행, 민간부문의 환경 운동의 활성화 등 바람직 한 현상이 전개되고 있어, 공원 녹지는 미래의 도시 관리 에 있어 주요 관심사가 될 것이다.

• Journal of Intelligence and Information Systems
• /
• v.17 no.4
• /
• pp.157-173
• /
• 2011

As the Internet use explodes recently, the malicious attacks and hacking for a system connected to network occur frequently. This means the fatal damage can be caused by these intrusions in the government agency, public office, and company operating various systems. For such reasons, there are growing interests and demand about the intrusion detection systems (IDS)-the security systems for detecting, identifying and responding to unauthorized or abnormal activities appropriately. The intrusion detection models that have been applied in conventional IDS are generally designed by modeling the experts' implicit knowledge on the network intrusions or the hackers' abnormal behaviors. These kinds of intrusion detection models perform well under the normal situations. However, they show poor performance when they meet a new or unknown pattern of the network attacks. For this reason, several recent studies try to adopt various artificial intelligence techniques, which can proactively respond to the unknown threats. Especially, artificial neural networks (ANNs) have popularly been applied in the prior studies because of its superior prediction accuracy. However, ANNs have some intrinsic limitations such as the risk of overfitting, the requirement of the large sample size, and the lack of understanding the prediction process (i.e. black box theory). As a result, the most recent studies on IDS have started to adopt support vector machine (SVM), the classification technique that is more stable and powerful compared to ANNs. SVM is known as a relatively high predictive power and generalization capability. Under this background, this study proposes a novel intelligent intrusion detection model that uses SVM as the classification model in order to improve the predictive ability of IDS. Also, our model is designed to consider the asymmetric error cost by optimizing the classification threshold. Generally, there are two common forms of errors in intrusion detection. The first error type is the False-Positive Error (FPE). In the case of FPE, the wrong judgment on it may result in the unnecessary fixation. The second error type is the False-Negative Error (FNE) that mainly misjudges the malware of the program as normal. Compared to FPE, FNE is more fatal. Thus, when considering total cost of misclassification in IDS, it is more reasonable to assign heavier weights on FNE rather than FPE. Therefore, we designed our proposed intrusion detection model to optimize the classification threshold in order to minimize the total misclassification cost. In this case, conventional SVM cannot be applied because it is designed to generate discrete output (i.e. a class). To resolve this problem, we used the revised SVM technique proposed by Platt(2000), which is able to generate the probability estimate. To validate the practical applicability of our model, we applied it to the real-world dataset for network intrusion detection. The experimental dataset was collected from the IDS sensor of an official institution in Korea from January to June 2010. We collected 15,000 log data in total, and selected 1,000 samples from them by using random sampling method. In addition, the SVM model was compared with the logistic regression (LOGIT), decision trees (DT), and ANN to confirm the superiority of the proposed model. LOGIT and DT was experimented using PASW Statistics v18.0, and ANN was experimented using Neuroshell 4.0. For SVM, LIBSVM v2.90-a freeware for training SVM classifier-was used. Empirical results showed that our proposed model based on SVM outperformed all the other comparative models in detecting network intrusions from the accuracy perspective. They also showed that our model reduced the total misclassification cost compared to the ANN-based intrusion detection model. As a result, it is expected that the intrusion detection model proposed in this paper would not only enhance the performance of IDS, but also lead to better management of FNE.

• Microbiology and Biotechnology Letters
• /
• v.45 no.3
• /
• pp.250-256
• /
• 2017

The prevalence of infections due to pathogenic bacteria such as Edwardsiella tarda, Streptococcus parauberis, and Photobacterium phosphoreum in fish farms in Jeju Island and their management by marine-derived biomaterials was studied. In this study, we isolated eight spices type of marine-derived biomaterials from four sea areas of Jeju Island. An antibiotic disc susceptibility test confirmed that the isolated marine-derived biomaterials showed weak resistance only to oxytetracycline and penicillin and sensitivity to the other antibiotics tested, and antimicrobial activity against fish pathogens with the inhibitory zone of 22 mm, 18 mm, and 19 mm for MD-02, MD-04, and MD-06 against E. tarda strains, respectively, and 19 mm, 22 mm, 30 mm, and 29 mm for MD-01, MD-02, MD-04, and MD-06 against S. parauberis strains, respectively, while all the marine-derived biomaterials showed antibacterial activity against P. phosphoreum. Among the eight biomaterials selected, Bacillus subtilis MD-02 displayed the greatest antibacterial activity against the three tested fish pathogens and also displayed susceptibility to antibiotics. The growth of Bacillus subtilis MD-02 was greatest with the carbon source, dextrine; nitrogen source, peptone; and mineral source, $MgSO_4{\cdot}7H_2O$. Hence, the present study confirmed that the isolate B. subtilis MD-02 from Jeju Island could be a potential antimicrobial agent against fish pathogens and a potential pharmacotherapeutic agent.

• Korean Journal of Cognitive Science
• /
• v.21 no.1
• /
• pp.95-126
• /
• 2010

This study proposes a bottom-up and inductive manual mapping methodology for integrating two heterogenous fine-grained ontologies which were built by a top-down and deductive methodology, namely the Sejong semantic classes (SJSC) and the upper nodes in KorLexNoun 1.5 (KLN), for HLP applications. It also discusses various problematics in the mapping processes of two language resources caused by their heterogeneity and proposes the solutions. The mapping methodology of heterogeneous fine-grained ontologies uses terminal nodes of SJSC and Least Upper Bounds (LUB) of KLN as basic mapping units. Mapping procedures are as follows: first, the mapping candidate groups are decided by the lexfollocorrelation between the synsets of KLN and the noun senses of Sejong Noun Dfotionaeci(SJND) which are classified according to SJSC. Secondly, the meanings of the candidate groups are precisely disambiguated by linguistic information provided by the two ontologies, i.e. the hierarchicllostructures, the definitions, and the exae les. Thirdly, the level of LUB is determined by applying the appropriate predicates and definitions of SJSC to the upper-lower and sister nodes of the candidate LUB. Fourthly, the mapping possibility ic inthe terminal node of SJSC is judged by che aring hierarchicllorelations of the two ontologies. Finally, the ituorrect synsets of KLN and terminologiollocandidate groups are excluded in the mapping. This study positively uses various language information described in each ontology for establishing the mapping criteria, and it is indeed the advantage of the fine-grained manual mapping. The result using the proposed methodology shows that 6,487 LUBs are mapped with 474 terminal and non-terminal nodes of SJSC, excluding the multiple mapped nodes, and that 88,255 nodes of KLN are mapped including all lower-level nodes of the mapped LUBs. The total mapping coverage is 97.91% of KLN synsets. This result can be applied in many elaborate syntactic and semantic analyses for Korean language processing.

• Journal of Chest Surgery
• /
• v.31 no.12
• /
• pp.1172-1182
• /
• 1998

Background: Primary goal of anticoagulation treatment in patients with mechanical heart valve is the effective prevention of thromboembolism and safe avoidance of bleeding as well. Material and Method: Two-hundred and nine patients with the St. Jude Medical prosthesis operated on between 1984 and 1995, for mitral(MVR 122), aortic(AVR 39) and double mitral and aortic valve replacement(DVR 48) respectively, were studied on the practically achieved levels of anticoagulation and the clinical outcomes. Patients were on Coumadin and followed up by monthly visit to outpatient clinic for examination and prothrombin time measurement to adjust the International Normalized Ratios(INRs) within the low-intensity target range between 1.5 and 2.5. Result: A total anticoagulation follow-up period was 1082.0 patient- years(mean 62.1 months) and INRs of 10,205 measurements were available for evaluation. The accomplished INRs among the replacement groups were not significantly different and only 65% of INRs were within the target range. And, in individual patients, only 37% of patients had INRs included within the target range in more than 70% of tests during follow-up period. The levels of INRs in patients with atrial fibrillation, which was found in 57% of patients, were definitely higher than the ones measured in patients with regular rhythm(p<0.001). Thromboembolisms were experienced by 15 patients with the incidence of 1.265%/patient- year(MVR 1.412%, AVR 0.462% and DVR 1.531%/patient-year) and major bleeding by 4 patients with the incidence of 0.337%/patient-year(MVR 0.424%, AVR none and DVR 0.383%/patient-year). Frequent as well as prolonged missing of prothrombin time tests was the main risk factor strongly associated with the thromboembolic complications(odds ratio 1.99). The proportion of INRs within target range of less than 60% in individual patient was the highly significant risk factor of both thromboembolic and overall embolic and bleeding complications(p<0.004 and p<0.002 respectively). Conclusion: In conclusion, the low-intensity therapeutic target range of INRs was adequate in patients with AVR and in sinus rhythm. However, the patients with replacement of the mitral valve were more likely to require higher target range of INRs, especially in the presence of atrial fibrillation, to achieve the practical levels of anticoagulation enough to prevent thromboembolic complications effectively. For the higher therapeutic target range of INRs between 2.0∼3.0, further accumulation of clinical evidences are required. It is highly desirable to improve the patients' compliance under continuous instructions in visiting outpatient clinic and in taking daily Coumadin without omission and to keep INRs consistently within optimal range with tight control for minimization of chances and of periods of exposure to the risk of complications. And, particularly, patients with high risk of complications and with wide fluctuation of INRs should be better managed with frequent monitoring anticoagulation levels.

• Journal of Chest Surgery
• /
• v.37 no.4
• /
• pp.356-363
• /
• 2004

Esophageal cancer is an aggressive disease with a poor prognosis. Recently, every effort has been made to improve the long term survival, but the general prognosis for patients with this disease remains poor. In this study, we reviewed 8 years of experiences with esophageal cancer patients managed in our department at Dong-A University Hospital and evaluated the effectiveness of cervical lymph node dissection performed selectively. Material and Method: From January 1995 to August 2003, 70 patients underwent esophagectomy for esophageal cancer in our department. Among them, 51 patients who underwent curative resection, had no double primary tumors and no neoadjuvant therapy were analyzed retrospectively. In most patients, intrathoracic esophagectomy and cervical esophago-gastrostomy was performed. Since 1997, 3-field lymph node dissection was performed selectively. Result: There were 46 men and 15 women. The median age was 60 years. The tumor was located in the upper third part in 10 patients (19%), middle third in 21 (41%), and lower third in 20 (40%). Majority of the patients (90%) had squamous cell carcinoma. Cervical anastomosis was made in 41 patients, and intrathoracic anastomosis in 10. 2-field lymph node dissection was done in 40 patients, and 3-field lymph node dissection in 11. The pathologic staging were as follows: stage I in 9 patients (17.6%), IIA in 20 (39.2%), IIIB in 7 (13.7%), III in 11 (21.6%), IVA in 2 (3.9%), and IVB in 2 (3.9%). The in-hospital mortality was 3.9% (2 patients) and complications occurred in 24 patients (47%). Overall actuarial 1, 3, and 5-year survival rates were 74.4%, 48.4%, and 48.4% including operative mortality. The 4-year survival rate did not differ significantly between 3-field lymph node dissection group (50.5%) and 2-field lymph node dissection group (48.9%). In 3-field lymph node dissection group, the respiratory complications were more frequent and operative time was significantly longer. Conclusion: We think that curative resection for esophageal cancer can be performed with acceptable mortality, and aggressive surgical approach may improve the long term survival. even for advanced stages. Effectiveness of 3-field lymph node dissection needs further investigations.

• Food Science and Preservation
• /
• v.22 no.4
• /
• pp.512-519
• /
• 2015

In this study, the effects of gamma-radiation treatment on cell wall composition and physiological characteristics of astringent persimmon fruit were investigated. The soluble tannin contents of gamma-radiated samples were reduced by the radiation treatment. The hardness of the radiated fruit was decreased when compared to non-radiated fruit. Alcohol-insoluble component of the cell wall in the radiated fruit was decreased from 39.3 mg/g to 37.2 mg/g. The water-soluble content of the radiated fruit was increased from 11.4 mg/g to 13.9 mg/g. The cell wall content of the non-radiated fruit was 26.6 mg/g whereas the cell wall content of radiated fruit was decreased to 23.1 mg/g. Due to the maturation of astringent persimmon fruit by gamma-radiation, water-soluble compounds were increased whereas decreasing in cell wall compounds. The contents of lignin, pectin, and cell wall were decreased from 0.82 mg/g and 3.56 mg/g to 0.77 mg/g and 3.14 mg/g, respectively. Acid-soluble hemicellulose content was decreased by gamma-radiation, while alkali-soluble hemicellulose and cellulose contents were increased. Activities of sotening enzyme as polygalacturonase, pectinesterase and $\beta$-galactosidase existed in persimmon fruit were increased by gamma-radiation. In the sensory evaluation, gamma-radition treated persimmon showed very low astringent taste when compared to the non-radiated fruit. In hardness test, the non-radiated persimmon maintained the hardness while gamma-treated persimmon showed softened outer layer due to the condensation of tannin during radiation treatment. Therefore, gamma-radiation treatment will be used for the removal of its astringency of persimmon fruit and for enhancement of its maturation.