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Construction of Event Networks from Large News Data Using Text Mining Techniques (텍스트 마이닝 기법을 적용한 뉴스 데이터에서의 사건 네트워크 구축)

  • Lee, Minchul;Kim, Hea-Jin
    • Journal of Intelligence and Information Systems
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    • v.24 no.1
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    • pp.183-203
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    • 2018
  • News articles are the most suitable medium for examining the events occurring at home and abroad. Especially, as the development of information and communication technology has brought various kinds of online news media, the news about the events occurring in society has increased greatly. So automatically summarizing key events from massive amounts of news data will help users to look at many of the events at a glance. In addition, if we build and provide an event network based on the relevance of events, it will be able to greatly help the reader in understanding the current events. In this study, we propose a method for extracting event networks from large news text data. To this end, we first collected Korean political and social articles from March 2016 to March 2017, and integrated the synonyms by leaving only meaningful words through preprocessing using NPMI and Word2Vec. Latent Dirichlet allocation (LDA) topic modeling was used to calculate the subject distribution by date and to find the peak of the subject distribution and to detect the event. A total of 32 topics were extracted from the topic modeling, and the point of occurrence of the event was deduced by looking at the point at which each subject distribution surged. As a result, a total of 85 events were detected, but the final 16 events were filtered and presented using the Gaussian smoothing technique. We also calculated the relevance score between events detected to construct the event network. Using the cosine coefficient between the co-occurred events, we calculated the relevance between the events and connected the events to construct the event network. Finally, we set up the event network by setting each event to each vertex and the relevance score between events to the vertices connecting the vertices. The event network constructed in our methods helped us to sort out major events in the political and social fields in Korea that occurred in the last one year in chronological order and at the same time identify which events are related to certain events. Our approach differs from existing event detection methods in that LDA topic modeling makes it possible to easily analyze large amounts of data and to identify the relevance of events that were difficult to detect in existing event detection. We applied various text mining techniques and Word2vec technique in the text preprocessing to improve the accuracy of the extraction of proper nouns and synthetic nouns, which have been difficult in analyzing existing Korean texts, can be found. In this study, the detection and network configuration techniques of the event have the following advantages in practical application. First, LDA topic modeling, which is unsupervised learning, can easily analyze subject and topic words and distribution from huge amount of data. Also, by using the date information of the collected news articles, it is possible to express the distribution by topic in a time series. Second, we can find out the connection of events in the form of present and summarized form by calculating relevance score and constructing event network by using simultaneous occurrence of topics that are difficult to grasp in existing event detection. It can be seen from the fact that the inter-event relevance-based event network proposed in this study was actually constructed in order of occurrence time. It is also possible to identify what happened as a starting point for a series of events through the event network. The limitation of this study is that the characteristics of LDA topic modeling have different results according to the initial parameters and the number of subjects, and the subject and event name of the analysis result should be given by the subjective judgment of the researcher. Also, since each topic is assumed to be exclusive and independent, it does not take into account the relevance between themes. Subsequent studies need to calculate the relevance between events that are not covered in this study or those that belong to the same subject.

K-Ar and $^{40}$ Ar/$^{39}$ Ar Ages from Metasediments in the Okcheon Metamorphic Belt and their Tectonic Implication (옥천 변성대 변성퇴적암의 K-Ar및 $^{40}$ Ar/$^{39}$ Ar 연대와 그 의의)

  • 김성원;오창환;이덕수;이정후
    • The Journal of the Petrological Society of Korea
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    • v.12 no.2
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    • pp.79-99
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    • 2003
  • Muscovite and biotite from 52 metasediments and 5 granites in the Hwasan area, the southwest of the Okcheon metamorphic belt and the Miwon-Jeungpyeong area, central Okcheon metamorphic belt were dated by the K-Ar and $^{40}$ Ar/$^{39}$ Ar methods. Muscovite and biotite ages from metapelitic and psammitic rocks (metasediments) of the Boeun and Pibanryeong units in the Hwasan area are concentrated in the mid-Jurassic (149-180 Ma). K-Ar and $^{40}$ Ar/$^{39}$ Ar ages for metapelitic and psammitic rocks of the Boeun and Pibanryeong units in the Miwon-Jeungpyeong area show complicated age distribution. Muscovite and biotite ages are classified by three groups, 142-194 Ma, 216-234 Ma, and 241-277 Ma. Younger (Cretaceous) ages occur only in metasediments close to Cretaceous granitic rocks in the southeastern region and the older ages of 216-277 Ma are restricted to the middle Part of the Jeungpyeong area. Most ages in the other area of the central Okcheon metamorphic belt fall between 142-194 Ma (Jurassic). K-Ar and $^{40}$ Ar/$^{39}$ Ar ages for granite from the northern part in the both the southwest and central Okcheon metamorphic belt also gave middle Jurassic ages (156-168 Ma). The similar ages from both metasediments and granites in the study areas indicate simultaneous cooling of both rocks to 300-350$^{\circ}C$ during the middle Jurassic. The state of graphitization of carbonaceous material of all metasediments in the study areas Indicates fully ordered graphite falling within a small range, from 3.353 to 3.359 ${\AA}$, which indicate amphibolite facies regional metamorphism. In the southern sector of the Boeun unit from the Hwasan area, metamorphic grade indicated by mineral paragenesis during regional intermediate-P/T metamorphism is greenschist facies. Whereas, the $d_{002}$ values for carbonaceous materials in the same sector show fully ordered graphite (ca. 500$^{\circ}C$) indicating amphibolite facies. This result with the concentration of mica ages of metasediments into the middle Jurassic, the presence of low-P/T thermal metamorphic zone (>500$^{\circ}C$) in the metasediments close to the Jurassic granite and the regional intrusion of Jurassic granites and their middle Jurassic intrusion and cooling ages may indicate the low-P/T regional thermal event during the early(\ulcorner)-middle Jurassic after main intermediate-P/T metamorphism which formed main mineral assemblage regionally in the study area. The regional thermal event failed, however, to reset the mineral assemblage of regional intermediate-P/T metamorphism except for narrow aureole (1-2 km) around Jurassic granite because e duration of thermal effect was relatively short by repid cooling of the Jurassic granite. In the middle part of the Jeungpyeong area, central Ogcheon metamorphic belt, muscovite and biotite K-Ar ages from 5 samples are 263-277 Ma and 241-249 Ma, respectively. An intermediate-P/T metamorphism is currently accepted to have occurred between 280 and 300 Ma. Therefore, the muscovite and biotite ages can be interpreted as cooling ages after Ml metamorphism indicating rapid cooling to ca 350$^{\circ}C$ between 280-300 Ma and 263-271 Ma, and biotite ages indicate slower cooling to ca. 300$^{\circ}C$ between 263-277 Ma and 241-249 Ma. However, more detail study is needed to confirm why the Permian to Triassic ages occur only in the middle Part of the Jeungpyeong area.a.

Prehospital Status of the Patients with Ischemic Chest Pain before Admitting in the Emergency Department (허혈성 흉통 환자의 응급의료센터 방문 전 상황)

  • Jin, Hye-Hwa;Lee, Sam-Beom;Do, Byung-Soo;Chun, Byung-Yeol
    • Journal of Yeungnam Medical Science
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    • v.24 no.1
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    • pp.41-54
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    • 2007
  • Background : The causes of chest pain vary but the leading cause of chest pain is ischemic heart disease. Mortality from ischemic chest pain has increased more than two fold over the last ten years. The purpose of this study was to determine the data necessary for rapid treatment of patients with signs and symptoms of ischemic chest pain in the emergency department (ED). Materials and Methods : We interviewed 170 patients who had ischemic chest pain in the emergency department of Yeungnam University Hospital over 6 months with a protocol developed for the evaluation. The protocol used included gender, age, arriving time, prior hospital visits, methods of transportation to the hospital, past medical history, final diagnosis, and outcome information from follow up. Results : Among 170 patients, there were 118 men (69.4%) and the mean age was 63 years. The patients diagnosed with acute myocardial infarction (AMI) were 106 (62.4%) and with angina pectoris (AP) were 64 (37.6%). The patients who had visited another hospital were 68.8%, twice the number that came directly to this hospital (p<0.05). The ratio of patients who visited another hospital were higher for the AMI (75.5%) than the AP (59.4%) patients (p<0.05). The median time spent deciding whether to go to hospital was 521 minutes and for transportation was 40 minutes. With regard to patients that visited another hospital first, the median time spent at the other hospital was 40 minutes. The total median time spent before arriving at our hospital was 600 minutes (p>0.05). The patients who had a total time delay of over 6 hours was similar 54.8% in the AMI group and 57.9% in the AP group (p>0.05). As a result, only 12.2% of the patients with an AMI received thrombolytics, and 48.8% of them had a simultaneous percutaneous coronary intervention (PCI). In the emergency department 8.5% of the patients with an AMI died. Conclusion : Timing is an extremely important factor for the treatment of ischemic heart disease. Most patients arrive at the hospital after a long time lapse from the onset of chest pain. In addition, most patients present to a different hospital before they arrive at the final hospital for treatment. Therefore, important time is lost and opportunities for treatment with thrombolytics and/or PCI are diminished leading to poor outcomes for many patients in the ED. The emergency room treatment must improve for the identification and treatment of ischemic heart disease so that patients can present earlier and treatment can be started as soon as they present to an emergency room.

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A Refined Method for Quantification of Myocardial Blood Flow using N-13 Ammonia and Dynamic PET (N-13 암모니아와 양전자방출단층촬영 동적영상을 이용하여 심근혈류량을 정량화하는 새로운 방법 개발에 관한 연구)

  • Kim, Joon-Young;Lee, Kyung-Han;Kim, Sang-Eun;Choe, Yearn-Seong;Ju, Hee-Kyung;Kim, Yong-Jin;Kim, Byung-Tae;Choi, Yong
    • The Korean Journal of Nuclear Medicine
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    • v.31 no.1
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    • pp.73-82
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    • 1997
  • Regional myocardial blood flow (rMBF) can be noninvasively quantified using N-13 ammonia and dynamic positron emission tomography (PET). The quantitative accuracy of the rMBF values, however, is affected by the distortion of myocardial PET images caused by finite PET image resolution and cardiac motion. Although different methods have been developed to correct the distortion typically classified as partial volume effect and spillover, the methods are too complex to employ in a routine clinical environment. We have developed a refined method incorporating a geometric model of the volume representation of a region-of-interest (ROI) into the two-compartment N-13 ammonia model. In the refined model, partial volume effect and spillover are conveniently corrected by an additional parameter in the mathematical model. To examine the accuracy of this approach, studies were performed in 9 coronary artery disease patients. Dynamic transaxial images (16 frames) were acquired with a GE $Advance^{TM}$ PET scanner simultaneous with intravenous injection of 20 mCi N-13 ammonia. rMBF was examined at rest and during pharmacologically (dipyridamole) induced coronary hyperemia. Three sectorial myocardium (septum, anterior wall and lateral wall) and blood pool time-activity curves were generated using dynamic images from manually drawn ROIs. The accuracy of rMBF values estimated by the refined method was examined by comparing to the values estimated using the conventional two-compartment model without partial volume effect correction rMBF values obtained by the refined method linearly correlated with rMBF values obtained by the conventional method (108 myocardial segments, correlation coefficient (r)=0.88). Additionally, underestimated rMBF values by the conventional method due to partial volume effect were corrected by theoretically predicted amount in the refined method (slope(m)=1.57). Spillover fraction estimated by the two methods agreed well (r=1.00, m=0.98). In conclusion, accurate rMBF values can be efficiently quantified by the refined method incorporating myocardium geometric information into the two-compartment model using N-13 ammonia and PET.

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Stress/Rest Tc-99m-MIBI SPECT in Comparison with Rest/Stress Rubidium-82 PET (휴식/부하 심근 Rubidium-82 양전자단층촬영과 부하/휴식 심근 Tc-99m-MIBI 단일광자단층촬영의 비교)

  • Lee, D.S.;Kang, K.W.;Lee, K.H.;Jeong, J.M.;Kwark, C.;Chung, J.K.;Lee, M.C.;Seo, J.D.;Koh, C.S.
    • The Korean Journal of Nuclear Medicine
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    • v.29 no.1
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    • pp.31-40
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    • 1995
  • We compared stress/rest myocardial Tc-99m-MIBl tomographic image findings with rest/stress rubidium-82 tomographic images. In 23 patients with coronary artery disease (12 of them received bypass grafts before) and 6 normal subjects, rest rubidium PET study was performed : rubidium-82 and Tc-99m-MIBI were injected simultaneously to each patient after dipyridamole stress for rubidium PET and MIBI SPECT; and rest MIBI SPECT was performed 4 hours thereafter. We scored segmental decrease of rubidium or MIBI uptakes into 5 grades for 29 segments from 3 short-axis, vertical and horizontal slices. Scores were summed for each major arterial territory. When more score than two grade-2's or one grade-3 was considered as the cue for significant stenosis for major arterial territories, 67% of 46 stenosed arteries were found with MIBI studies and 78% of them by rubidium studies. Fourteen among 28 grafted arterial territories of 12 post-CABG patients were found normal with both rubidium and MIBI. Segmental scores were concordant between rubidium and MIBI in 72% of 709 stress segments and in 80% of 825 rest segments. Stress rubidium segmental scores were less than stress MIBI scores in 9%, so were rest rubidium scores. Stress rubidium scores were more than stress MIBI scores in 20% of segments, and rest rubidium segmental scores were more than rest MIBl scores in 11%. Rank correlations (Spearman's rho's more than 0.7(stress) and 0.5(rest), slopes (MIBI/rubidium) around 0.7(stress) and 0.9 (rest)) suggested deeper and wider defects in stress with rubidium. Slope over 1 (MIBI/rubidium) with LAD segemental scores at rest and 7 territories which had much larger score with MIBI revealed exaggeration of rest defects with rest MIBI in same-day stress/rest study. Difference scores (stress-rest for each territory) suggesting Ischemia were larger with rubidium (slope of MIBI/rubidium around 0.45). As has been implied by animal or separate-day-human studies, these segmental analyses with simultaneous examination in patients told that rubidium PET flow studies disclose ischemia more often than MIBI studies and that rest MIBI studies in same-day stress/rest-sequence gave a little larger rest defect than they would have shown.

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Adaptive RFID anti-collision scheme using collision information and m-bit identification (충돌 정보와 m-bit인식을 이용한 적응형 RFID 충돌 방지 기법)

  • Lee, Je-Yul;Shin, Jongmin;Yang, Dongmin
    • Journal of Internet Computing and Services
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    • v.14 no.5
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    • pp.1-10
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    • 2013
  • RFID(Radio Frequency Identification) system is non-contact identification technology. A basic RFID system consists of a reader, and a set of tags. RFID tags can be divided into active and passive tags. Active tags with power source allows their own operation execution and passive tags are small and low-cost. So passive tags are more suitable for distribution industry than active tags. A reader processes the information receiving from tags. RFID system achieves a fast identification of multiple tags using radio frequency. RFID systems has been applied into a variety of fields such as distribution, logistics, transportation, inventory management, access control, finance and etc. To encourage the introduction of RFID systems, several problems (price, size, power consumption, security) should be resolved. In this paper, we proposed an algorithm to significantly alleviate the collision problem caused by simultaneous responses of multiple tags. In the RFID systems, in anti-collision schemes, there are three methods: probabilistic, deterministic, and hybrid. In this paper, we introduce ALOHA-based protocol as a probabilistic method, and Tree-based protocol as a deterministic one. In Aloha-based protocols, time is divided into multiple slots. Tags randomly select their own IDs and transmit it. But Aloha-based protocol cannot guarantee that all tags are identified because they are probabilistic methods. In contrast, Tree-based protocols guarantee that a reader identifies all tags within the transmission range of the reader. In Tree-based protocols, a reader sends a query, and tags respond it with their own IDs. When a reader sends a query and two or more tags respond, a collision occurs. Then the reader makes and sends a new query. Frequent collisions make the identification performance degrade. Therefore, to identify tags quickly, it is necessary to reduce collisions efficiently. Each RFID tag has an ID of 96bit EPC(Electronic Product Code). The tags in a company or manufacturer have similar tag IDs with the same prefix. Unnecessary collisions occur while identifying multiple tags using Query Tree protocol. It results in growth of query-responses and idle time, which the identification time significantly increases. To solve this problem, Collision Tree protocol and M-ary Query Tree protocol have been proposed. However, in Collision Tree protocol and Query Tree protocol, only one bit is identified during one query-response. And, when similar tag IDs exist, M-ary Query Tree Protocol generates unnecessary query-responses. In this paper, we propose Adaptive M-ary Query Tree protocol that improves the identification performance using m-bit recognition, collision information of tag IDs, and prediction technique. We compare our proposed scheme with other Tree-based protocols under the same conditions. We show that our proposed scheme outperforms others in terms of identification time and identification efficiency.

Deep Learning-based Professional Image Interpretation Using Expertise Transplant (전문성 이식을 통한 딥러닝 기반 전문 이미지 해석 방법론)

  • Kim, Taejin;Kim, Namgyu
    • Journal of Intelligence and Information Systems
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    • v.26 no.2
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    • pp.79-104
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    • 2020
  • Recently, as deep learning has attracted attention, the use of deep learning is being considered as a method for solving problems in various fields. In particular, deep learning is known to have excellent performance when applied to applying unstructured data such as text, sound and images, and many studies have proven its effectiveness. Owing to the remarkable development of text and image deep learning technology, interests in image captioning technology and its application is rapidly increasing. Image captioning is a technique that automatically generates relevant captions for a given image by handling both image comprehension and text generation simultaneously. In spite of the high entry barrier of image captioning that analysts should be able to process both image and text data, image captioning has established itself as one of the key fields in the A.I. research owing to its various applicability. In addition, many researches have been conducted to improve the performance of image captioning in various aspects. Recent researches attempt to create advanced captions that can not only describe an image accurately, but also convey the information contained in the image more sophisticatedly. Despite many recent efforts to improve the performance of image captioning, it is difficult to find any researches to interpret images from the perspective of domain experts in each field not from the perspective of the general public. Even for the same image, the part of interests may differ according to the professional field of the person who has encountered the image. Moreover, the way of interpreting and expressing the image also differs according to the level of expertise. The public tends to recognize the image from a holistic and general perspective, that is, from the perspective of identifying the image's constituent objects and their relationships. On the contrary, the domain experts tend to recognize the image by focusing on some specific elements necessary to interpret the given image based on their expertise. It implies that meaningful parts of an image are mutually different depending on viewers' perspective even for the same image. So, image captioning needs to implement this phenomenon. Therefore, in this study, we propose a method to generate captions specialized in each domain for the image by utilizing the expertise of experts in the corresponding domain. Specifically, after performing pre-training on a large amount of general data, the expertise in the field is transplanted through transfer-learning with a small amount of expertise data. However, simple adaption of transfer learning using expertise data may invoke another type of problems. Simultaneous learning with captions of various characteristics may invoke so-called 'inter-observation interference' problem, which make it difficult to perform pure learning of each characteristic point of view. For learning with vast amount of data, most of this interference is self-purified and has little impact on learning results. On the contrary, in the case of fine-tuning where learning is performed on a small amount of data, the impact of such interference on learning can be relatively large. To solve this problem, therefore, we propose a novel 'Character-Independent Transfer-learning' that performs transfer learning independently for each character. In order to confirm the feasibility of the proposed methodology, we performed experiments utilizing the results of pre-training on MSCOCO dataset which is comprised of 120,000 images and about 600,000 general captions. Additionally, according to the advice of an art therapist, about 300 pairs of 'image / expertise captions' were created, and the data was used for the experiments of expertise transplantation. As a result of the experiment, it was confirmed that the caption generated according to the proposed methodology generates captions from the perspective of implanted expertise whereas the caption generated through learning on general data contains a number of contents irrelevant to expertise interpretation. In this paper, we propose a novel approach of specialized image interpretation. To achieve this goal, we present a method to use transfer learning and generate captions specialized in the specific domain. In the future, by applying the proposed methodology to expertise transplant in various fields, we expected that many researches will be actively conducted to solve the problem of lack of expertise data and to improve performance of image captioning.

Geochemical Equilibria and Kinetics of the Formation of Brown-Colored Suspended/Precipitated Matter in Groundwater: Suggestion to Proper Pumping and Turbidity Treatment Methods (지하수내 갈색 부유/침전 물질의 생성 반응에 관한 평형 및 반응속도론적 연구: 적정 양수 기법 및 탁도 제거 방안에 대한 제안)

  • 채기탁;윤성택;염승준;김남진;민중혁
    • Journal of the Korean Society of Groundwater Environment
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    • v.7 no.3
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    • pp.103-115
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    • 2000
  • The formation of brown-colored precipitates is one of the serious problems frequently encountered in the development and supply of groundwater in Korea, because by it the water exceeds the drinking water standard in terms of color. taste. turbidity and dissolved iron concentration and of often results in scaling problem within the water supplying system. In groundwaters from the Pajoo area, brown precipitates are typically formed in a few hours after pumping-out. In this paper we examine the process of the brown precipitates' formation using the equilibrium thermodynamic and kinetic approaches, in order to understand the origin and geochemical pathway of the generation of turbidity in groundwater. The results of this study are used to suggest not only the proper pumping technique to minimize the formation of precipitates but also the optimal design of water treatment methods to improve the water quality. The bed-rock groundwater in the Pajoo area belongs to the Ca-$HCO_3$type that was evolved through water/rock (gneiss) interaction. Based on SEM-EDS and XRD analyses, the precipitates are identified as an amorphous, Fe-bearing oxides or hydroxides. By the use of multi-step filtration with pore sizes of 6, 4, 1, 0.45 and 0.2 $\mu\textrm{m}$, the precipitates mostly fall in the colloidal size (1 to 0.45 $\mu\textrm{m}$) but are concentrated (about 81%) in the range of 1 to 6 $\mu\textrm{m}$in teams of mass (weight) distribution. Large amounts of dissolved iron were possibly originated from dissolution of clinochlore in cataclasite which contains high amounts of Fe (up to 3 wt.%). The calculation of saturation index (using a computer code PHREEQC), as well as the examination of pH-Eh stability relations, also indicate that the final precipitates are Fe-oxy-hydroxide that is formed by the change of water chemistry (mainly, oxidation) due to the exposure to oxygen during the pumping-out of Fe(II)-bearing, reduced groundwater. After pumping-out, the groundwater shows the progressive decreases of pH, DO and alkalinity with elapsed time. However, turbidity increases and then decreases with time. The decrease of dissolved Fe concentration as a function of elapsed time after pumping-out is expressed as a regression equation Fe(II)=10.l exp(-0.0009t). The oxidation reaction due to the influx of free oxygen during the pumping and storage of groundwater results in the formation of brown precipitates, which is dependent on time, $Po_2$and pH. In order to obtain drinkable water quality, therefore, the precipitates should be removed by filtering after the stepwise storage and aeration in tanks with sufficient volume for sufficient time. Particle size distribution data also suggest that step-wise filtration would be cost-effective. To minimize the scaling within wells, the continued (if possible) pumping within the optimum pumping rate is recommended because this technique will be most effective for minimizing the mixing between deep Fe(II)-rich water and shallow $O_2$-rich water. The simultaneous pumping of shallow $O_2$-rich water in different wells is also recommended.

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Study on the Short-Term Hemodynamic Effects of Experimental Cardiomyoplasty in Heart Failure Model (심부전 모델에서 실험적 심근성형술의 단기 혈역학적 효과에 관한 연구)

  • Jeong, Yoon-Seop;Youm, Wook;Lee, Chang-Ha;Kim, Wook-Seong;Lee, Young-Tak;Kim, Won-Gon
    • Journal of Chest Surgery
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    • v.32 no.3
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    • pp.224-236
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    • 1999
  • Background: To evaluate the short-term effect of dynamic cardiomyoplasty on circulatory function and detect the related factors that can affect it, experimental cardiomyoplasties were performed under the state of normal cardiac function and heart failure. Material and Method: A total of 10 mongrel dogs weighing 20 to 30kg were divided arbitrarily into two groups. Five dogs of group A underwent cardiomyoplasty with latissimus dorsi(LD) muscle mobilization followed by a 2-week vascular delay and 6-week muscle training. Then, hemodynamic studies were conducted. In group B, doxorubicin was given to 5 dogs in an IV dose of 1 mg/kg once a week for 8 weeks to induce chronic heart failure, and simultaneous muscle training was given for preconditioning during this period. Then, cardiomyoplasties were performed and hemodynamic studies were conducted immediately after these cardiomyoplasties in group B. Result: In group A, under the state of normal cardiac function, only mean right atrial pressure significantly increased with the pacer-on(p<0.05) and the left ventricular hemodynamic parameters did not change significantly. However, with pacer-on in group B, cardiac output(CO), rate of left ventricular pressure development(dp/dt), stroke volume(SV), and left ventricular stroke work(SW) increased by 16.7${\pm}$7.2%, 9.3${\pm}$3.2%, 16.8${\pm}$8.6%, and 23.1${\pm}$9.7%, respectively, whereas left ventricular end-diastole pressure(LVEDP) and mean pulmonary capillary wedge pressure(mPCWP) decreased by 32.1${\pm}$4.6% and 17.7${\pm}$9.1%, respectively(p<0.05). In group A, imipramine was infused at the rate of 7.5mg/kg/hour for 34${\pm}$2.6 minutes to induce acute heart failure, which resulted in the reduction of cardiac output by 17.5${\pm}$2.7%, systolic left ventricular pressure by 15.8${\pm}$2.5% and the elevation of left ventricular end-diastole pressure by 54.3${\pm}$15.2%(p<0.05). With pacer-on under this state of acute heart failu e, CO, dp/dt, SV, and SW increased by 4.5${\pm}$1.8% and 3.1${\pm}$1.1%, 5.7${\pm}$3.6%, and 6.9${\pm}$4.4%, respectively, whereas LVEDP decreased by 11.7${\pm}$4.7%(p<0.05). Comparing CO, dp/dt, SV, SW and LVEDP that changed significantly with pacer-on, both under the state of acute and chronic heart failure, augmentation widths of these left ventricular hemodynamic parameters were significantly larger under the state of chronic heart failure(group B) than acute heart failure(group A)(p<0.05). On gross inspection, variable degrees of adhesion and inflammation were present in all 5 dogs of group A, including 2 dogs that showed no muscle contraction. No adhesion and inflammation were, however, present in all 5 dogs of group B, which showed vivid muscle contractions. Considering these differences in gross findings along with the following premise that the acute heart failure state was not statistically different from the chronic one in terms of left ventricular parameters(p>0.05), the larger augmentation effect seen in group B is presumed to be mainly attributed to the viability and contractility of the LD muscle. Conclusion: These results indicate that the positive circulatory augmentation effect of cardiomyoplasty is apparent only under the state of heart failure and the preservation of muscle contractility is important to maximize this effect.

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Postoperative Radiation Therapy in the Soft-tissue Sarcoma (연부 조직 육종의 수술 후 방사선 치료 결과)

  • Kim Yeon Shil;Jang Hong Seok;Yoon Sei Chul;Ryu Mi Ryeong;Kay Chul Seung;Chung Su Mi;Kim Hoon Kyo;Kang Yong Koo
    • Radiation Oncology Journal
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    • v.16 no.4
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    • pp.485-495
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    • 1998
  • Purpose : The major goal of the therapy in the soft tissue sarcoma is to control both local and distant tumor. However, the technique of obtaining local control has changed significantly over the past few decades from more aggressive surgery to combined therapy including conservative surgery and radiation and/or chemotherapy. We retrospectively analyzed the treatment results of the postoperative radiation therapy of soft tissue sarcoma and its prognostic factor. Materials and Methods : Between March 1983 and June 1994, 50 patients with soft tissue sarcoma were treated with surgery and postoperative radiation therapy at Kang-Nam St. Mary's hospital. Complete follow up was possible for all patients with median follow up duration 50 months (range 6-162 months). There were 28 male and 32 female patients. Their age ranged from 6 to 83 with a median of 44 years. Extremity (58$\%$) was the most frequent site of occurrence followed by trunk (20$\%$) and head and neck (12$\%$). Histologically malignant fibrous histiocytoma (23$\%$), liposarcoma (17$\%$), malignant schwannoma (12$\%$) constitute 52$\%$ of the patients. Daily radiation therapy designed to treat all areas at a risk for tumor spread upto dose of 4500-5000 cGy. A shrinking field technique was then used and total 55-65 Gy was delivered to tumor bed. Twenty-five patients (42$\%$) received chemotherapy with various regimen in the postoperative period. Results : Total 41 patients failed either with local recurrence or with distant metastasis. There were 29 patients (48$\%$) of local recurrence. Four patients (7$\%$) developed simultaneous local recurrence and distant metastasis and 8 patients (13$\%$) developed only distant metastasis. Local recurrence rate was rather higher than of other reported series. This study included patients of gross residual, recurrent cases after previous operation, trunk and head and neck Primary This feature is likely explanation for the decreased local control rate. Five of 29 Patients who failed only locally were salvaged by re-excision and/or re-irradiation and remained free of disease. Factors affecting local control include histologic type, grade, stage, extent of operation and surgical margin involvement, lymph node metastasis (p<0.05). All 21 patients who failed distantly are dead with progressive disease at the time of this report. Our overall survival results are similar to those of larger series. Actuarial 5 year overall survival and disease free survival were 60.4 $\%$, 30.6$\%$ respectively. Grade, stage (being close association with grade), residual disease (negative margin, microscopic, gross) were significant as a predictor of survival in our series (p<0.05). Conclusion : Combined surgery and postoperative radiation therapy obtained 5 year survival rate comparable to that of radical surgery.

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