• Title/Summary/Keyword: exact methods

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Selectivity Estimation using the Generalized Cumulative Density Histogram (일반화된 누적밀도 히스토그램을 이용한 공간 선택율 추정)

  • Chi, Jeong-Hee;Kim, Sang-Ho;Ryu, Keun-Ho
    • The KIPS Transactions:PartD
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    • v.11D no.4
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    • pp.983-990
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    • 2004
  • Multiple-count problem is occurred when rectangle objects span across several buckets. The CD histogram is a technique which selves this problem by keeping four sub-histograms corresponding to the four points of rectangle. Although It provides exact results with constant response time, there is still a considerable issue. Since it is based on a query window which aligns with a given grid, a number of errors nay be occurred when it is applied to real applications. In this paper, we propose selectivity estimation techniques using the generalized cumulative density histogram based on two probabilistic models : \circled1 probabilistic model which considers the query window area ratio, \circled2 probabilistic model which considers intersection area between a given grid and objects. Our method has the capability of eliminating an impact of the restriction on query window which the existing cumulative density histogram has. We experimented with real datasets to evaluate the proposed methods. Experimental results show that the proposed technique is superior to the existing selectivity estimation techniques. Furthermore, selectivity estimation technique based on probabilistic model considering the intersection area is very accurate(less than 5% errors) at 20% query window. The proposed techniques can be used to accurately quantify the selectivity of the spatial range query on rectangle objects.

A Comparative Study on Elementary School Science Curriculum and Textbooks between South and North Korea (남.북한 초등학교 자연과 교육과정 및 교과서 비교 연구)

  • Choi, Don-Hyung;Lee, Yang-Rak;Kim, Jae-Young;Noh, Suk-Goo
    • Journal of The Korean Association For Science Education
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    • v.18 no.1
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    • pp.43-60
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    • 1998
  • The purpose of this study is to compare and analyse the elementary school science curriculum and textbooks of South and North Korea, then gather the fundamental sources for the establishment of elementary school science curriculum after Unification of Korea by clarifying the difference and the likeness in educational objectives, contents, teaching methods of both Korean elementary school sciences. Based on this comparison and analysis, this study tried to give the concrete suggestions for the elementary school science curriculum and textbook development after Unification. For this, analyses were carried out for the curriculum managing systems, subject organization, education goal, emphasis on each field, teaching-learning and evaluation method. Besides, this study compared and analysed the elementary school science textbook development and distribution system, apparent format, content organization, ratio of content categories, content scope and level and the related terms appeared in both Korean elementary school science textbooks. The result of this study showed a lot of differences in the educational objectives, contents, and educational method of the elementary school science between South and North Korea. The grasping of these differences and the exact understanding about what causes these differences and how the differences are made must be the necessary work for the science curriculum establishment, especially for elementary school science curriculum and textbook development, after Unification.

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The success rate of Mg-incorporated oxidized implants in partially edentulous patients: a prospective clinical study (부분 무치악 환자에서 마그네슘 이온주입 임플란트의 성공률에 대한 전향적 임상연구)

  • Choi, Su-Jung;Yoo, Jung-Ho;Lee, Ku-Bok;Kim, Jin-Wook
    • The Journal of Korean Academy of Prosthodontics
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    • v.50 no.3
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    • pp.176-183
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    • 2012
  • Purpose: This study examined the clinical success rate of Mg titanate implants (M Implant system, Shinhung, Korea), which employ a Mg coating method, by evaluating the marginal bone loss and implant stability using radiographs and Osstell$^{(R)}$, over a 1 year. Materials and methods: The locations of the implants placement were divided into 4 areas; the maxillary and mandibular premolars and molars. In the maxilla, 8 and 9 implants were inserted in the premolar and molar areas, respectively. In the mandible, 11 and 51 implants were inserted in the premolar and molar areas. Marginal bone loss and ISQ of all implants (79) were measured after insertion, mounting the prosthetic appliance, and 1, 3, 6, and 12 months after loading. The marginal bone loss was measured from the radiograph using XCP bite, which was customized, and the implant stability measured using Osstell$^{(R)}$. Fisher's exact test (${\alpha}$=.05) was used to compare the success rates of each region. Results: The mean marginal bone loss for the upper and lower jaws were 1.537 mm and 1.172 mm. The mobility showed a non-significant reduction or increase according with time. The success rates were accounted for 94.12% and 98.39% in the upper and lower jaws; the premolars and molars were accounted for 100% and 96.67%. The two cases of early failure resulted from failure of primary stability during implant insertion. The late failures were not observed for 1 year after adding a loading to the implants. Conclusion: The Mg titanate implant showed good primary stability and good clinical results in both healing and function.

Analyzing the Cognition of CPR by College Students Who Major in Public Health or Not (보건계열과 비보건계열 대학생의 심폐소생술에 대한 인지도)

  • Kwon, Hayrran
    • The Korean Journal of Emergency Medical Services
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    • v.4 no.1
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    • pp.35-46
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    • 2000
  • The results of analyzing the cognition of CPR by college students who major in public health or not order to enhance the educational efficiency of first aid ability and its expansion are as follows. 1. In case of students majoring in public health, the students who have the knowledge of term 'CPR' are 95.3% of total 300 students and 62.6% of the students who don't major in public health know it. In the item test of examining the degree of theoretical knowledge of CPR, the cases who know all 12 items are 5.2% and 1.6% respectively in cases who major in public health and don't major in it and it is judged that the extension of educational opportunity for them should be urgent. 2. The students who have experienced the practice of CPR are 20.6% in case who major in public health and 7.4% in other case. Therefore it seems to desirable that indirect field experience should be obtained by strengthening practice centered education. 3. The order of practice to examine the CPR ability is asked and the students who show very good remark are just 21~22% in both cases and they conducted very ineffective CPR and it is examined that they did first aid which may a serious damage to patients. Then the cases who recovered pulse and respiration after CPR were very low as 28.8% in the students who major in public health and 35.7% in others. It is therefore considered that the exact education of conducting the maintenance of respiratory trace, artificial respiration and CPR is necessary. 4. The cases who had the education of CPR were 51% in the students who major in public health and 39.4% in others, who had little opportunities to have CPR and 92.5~93.2% in both groups fee the necessity of continuous education and it is very encouraging to extend the education of CPR. 5. The education of CPR is mainly done at school (70.3~79.4%) and from teachers (52.7~55.4%) and 71.2% of the students majoring in public health responded that it is good for them to have education of CPR at school and lecture by first-aider and 58.9% of others did it. The cases who ask for lecture by the Professors of Dept. of First-Aid are 11.8 in students majoring in public health and 13.1% in others and it is judged that lecture by them having the theoretical foundation and first-aider with practical ability will be desirable. 6. On teaching methods, 57.5% of the cases majoring in public health and 63.3% of others ask for practice and 20% of both groups need theory centered teaching. 7. On lecture fee, 83% of the cases majoring in public health and 83.3% of others consider it should be free and 8~11.8% who are to pay for 10,000 won and it is judged that it should be opened and operated as liberal arts by college in the dimension of lifelong education. 8. On the objects of education, 83% of cases majoring in public health and 66.6% of others consider it should be conducted in people of all ages and both sexes and it is known that everyone recognizes the necessity of popularizing the education of first-aid.

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Surgical Results for Perforated Gastric Cancer (천공성 위암의 수술 방법과 치료 결과)

  • Lee, Moon-Soo;Chae, Man-Kyu;Kim, Tae-Yun;Cho, Gyu-Seok;Kim, Sung-Yong;Baek-Moo-Jun;Chung-Il-Kwon;Park, Kyung-Kyu;Kim, Chang-Ho;Song-Ok-Pyung;Cho, Moo-Sik
    • Journal of Gastric Cancer
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    • v.2 no.2
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    • pp.85-90
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    • 2002
  • Purpose: Perforated gastric cancer (PGC) is rare and occurs in $1\∼4\%$ of all gastric cancers. Possible dissemination of tumor cells at the time of perforation of the gastric carcinoma has been a matter of concern. The intraoperative determination of what kind of operation should be done and how extensive the lymphnode dissection should be still remains controversial. The purpose of this study is to evaluate the factors influencing the survival and to determine the optimal treatment for PGC. Materials and Methods: A total of 42 patients were operated on for a perforated gastric carcinoma at Soonchunhyang University Chunan Hospital from 1983 to 2000. the age and the sexes of the patients, the location of perforation, the diameter of perforation, the histologic type of the tumor, the depth of wall invasion, the absence or presence of lymph node metastasis / distant metastasis, the stage of disease, the type of operation, and the outcomes were examined. Statistically significant differences were analyzed by using Fisher's exact test. Results: The stage distributions according to the UICC classification were 1 case of stage I, 6 cases of stage II, 17 cases of stage III, and 11 cases of stage IV. An emergency gastrectomy was done in 26 patients ($61.9\%$), with a 5-yr survival rate of $44\%$. The survival of patients was significantly influenced by the depth of wall invasion, the lymphnode metastasis, distant metastasis, the stage of disease, and the type of operation. Conclusions: an emergency gastrectomy is the treatment of choice for most patients with resectable PGC. Choosing more a optimistic surgical approach for potentially curative cases of PGC should be one way to increase the patient's survival rate.

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The effect of erythropoietin in neonatal rat model of hypoxic-ischemic brain injury (Erythropoietin의 투여가 신생백서 저산소허혈뇌손상에 미치는 영향)

  • Kim, Heng-Mi;Choe, Byung-Ho;Kwon, Soon-Hak;Sohn, Yoon-Kyung
    • Clinical and Experimental Pediatrics
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    • v.52 no.1
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    • pp.105-110
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    • 2009
  • Purpose : Perinatal asphyxia is an important cause of neonatal mortality and subsequent lifelong neurodevelopmental handicaps. Although many treatment strategies have been tested, there is currently no clinically effective treatment to prevent or reduce the harmful effects of hypoxia and ischemia in humans. Erythropoietin (Epo) has been shown to exert neuroprotective effects in various brain injury models although the exact mechanisms through which Epo functions are not completely understood. This study investigates the effect of Epo on hypoxic-ischemic (HI) brain injury and the possibility that its neuroprotective actions may be associated with iron-mediated metabolism. Methods : HI brain injury was produced in 7-day-old rats by unilateral carotid artery ligation followed by hypoxia with 8% oxygen for 2 h. At the end of HI brain injury, the rats received an intraperitoneal injection of 5,000 units/kg erythropoietin. Random premedication with iron, deferoxamine, iron-deferoxamine, or saline were performed 23 d before HI brain injury. The severity of the brain injury was assessed at 7 d after HI. Results : Single Epo treatment post-HI brain injury reduced the gross and histopathological findings of brain injury. Iron premedication did not increase the incidence or severity of the injury as measured by the damage score. Deferoxamine administration before HI brain injury improved the brain injury as compared to no treatment or Epo treatment. Conclusion : These findings indicate that Epo provides neuroprotective benefits after HI in the developing brain. These findings suggest that Epos neuroprotective actions may involve reducing iron in tissues that mediate the formation of free radicals.

Epidemiological Aspects of Osteosarcoma, Giant Cell Tumor and Chondrosarcoma Musculoskeletal Tumors - Experience of the National Rehabilitation Institute, Mexico City

  • DelaGarza-Montano, P;Estrada-Villasenor, E;Dominguez Rubio, R;Martinez-Lopez, V;Avila-Luna, A;Alfaro-Rodriguez, A;Garciadiego-Cazares, D;Carlos, A;Hernandez-Perez, AD;Bandala, C
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.15
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    • pp.6451-6455
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    • 2015
  • Background: Primary bone neoplasms are rare, contributing only 0.2% of the global burden of all human malignancies. Osteosarcoma (OS) and chondrosarcoma (CS) are the most common malignancies of bone. The giant cell tumor of bone (GCTb) is a benign tumor with behavior characterized by osteolytic bone destruction. The OS, CS and GCTb affect both sexes, all races and generally have incidence peaks regarding the age of the patient which vary according to the tumor type. We analyzed the incidences of OS, CS and GCTb and their relations with gender and age in patients treated in the National Rehabilitation Institute (INR, for its acronym in Spanish) over a period of nine years. Materials and Methods: In the study period, clinic pathological data for 384 patients were obtained with clinical, radiological and histopathological diagnosis for OS, GCTb and CS. Data analysis was performed using the chi-square and Fisher's exact tests. Results: From 2006 to 2014 were recorded 384 cases of bone malignancies in the database of INR. The GCTb had the highest incidence (53.1%), followed by OS (31.3%) and finally the CS (15.6%). The overall average age was $33.6{\pm}15.8$ years and the overall frequency of gender had a ratio of 1/1.03 male/female. The states with the highest incidence were Distrito Federal and Estado de Mexico with 29.2% and 25.3% respectively. Malignant neoplasms of bone assessed in the course of nine years show three significant increases in 2008, 2011 and 2014 (p=0.14). We found association between sex and tumor type (p=0.03), GCTb and CS predominated in females (54.9% and 56.6% respectively), while for the OS males were most affected (59.1%). Age was different in relation with tumor type (p=0.0001), average age was $24.3{\pm}11.2$ years for OS, $34.5{\pm}13$ years for GCTb and $49.2{\pm}18.5$ years for CS. Furthermore, associations of tumor type with topographic location of the primary tumor (P=0.0001) were found. Conclusions: In this study we can see that incidence of musculoskeletal tumor in our population is continuously increasing and in nine years an approximately 200% increase of musculoskeletal tumor cases was observed.

Low Frequency of ETV6-RUNX1 (t 12; 21) in Saudi Arabian Pediatric Acute Lymphoblastic Leukemia Patients: Association with Clinical Parameters and Early Remission

  • Aljamaan, Khaled;Aljumah, Talal khalid;Aloraibi, Saleh;Absar, Muhammad;Iqbal, Zafar
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.17
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    • pp.7523-7527
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    • 2015
  • Background: Pediatric acute lymphoblastic leukemia (pALL) patients at King Abdulaziz Medical City represent a pure Saudi Arabian population. ETV6-RUNX1 positive pALL patients have good prognosis as compared to ETV6-RUNX1 negative counterparts. Therefore, frequencies of these two patient groups have a huge consideration in treatment strategies of pALL in a given population. Different geographical locations have been reported to have different frequencies of ETV6-RUNX1 ranging from 10% in Southeast Asia to 30% in Australia. Aim: Therefore, the objective of this study was to establish the ETV6-RUNX1 status of Saudi Arabian pALL patients and its association with clinical parameters and early remission. Materials and Methods: Clinical parameters and ETV6-RUNX1 status (using FISH technique) of pALL patients attending the Pediatric Oncology Clinic, King Abdulaziz Medical City, Riyadh from 2006 to 2011 were studied. Comparisons between ETV6-RUNX1 positive and negative groups were accomplished using chi-square test or Fisher's exact test. All statistical analyses were performed using SAS version 9.2 (SAS Institute, Inc., Cary, NC). Results: Out of 54 patients, 33 were male and 21 were females (ratio 1.57:1). B- and T-cell lineages were found in 47 (87%) and 7 (13%) patients respectively. Only 5 (9.3%) patients were ETV6-RUNX1 positive while 49(80.7%) were ETV6-RUNX1 negative. All ETV6-RUNX1 patients (100%) were of B-cell lineage and 80% (4/5) were in the 3-7 year age group. None of the ETV6-RUNX11 patients had ${\geq}5%$ blasts (no remission) at day 14 as compared with 9% in the ETV6-RUNX1 negative group (Figure 1). Conclusions: Frequency of ETV6-RUNX1 positive patients (less than 10%) in our pALL patients is much lower than reported for most European countries, North America, Australia and Japan while it is in accordance with ETV6-RUNX1 frequencies from Egypt (11.6%), Pakistan (10%), Spain (2%) and India (5-7%). This shows ethnic differences in genetics of pALL as well as higher frequencies of ETV6-RUNX1 positive pALL mostly in more industrialized countries, probably due to some industrial pollutants or westernized lifestyle.

Associations of ERCC4 rs1800067 Polymorphism with Cancer Risk: an Updated Meta-analysis

  • Yuan, Quan;Liu, Jing-Wei;Xing, Cheng-Zhong;Yuan, Yuan
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.18
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    • pp.7639-7644
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    • 2014
  • Background: Results from previous studies concerning the association of ERCC4 rs1800067 polymorphism with risk of cancer were inconsistent. To explore the exact relation with susceptibility, we conducted the present meta-analysis. Materials and Methods: Literature of electronic databases including PubMed, Web of Science, EMBASE, Wanfang and Chinese National Knowledge Infrastructure (CNKI) were systematically searched. ORs and their 95%CIs were used to assess the strength of associations between ERCC4 polymorphism and cancer risk. Results: There was no significant association between ERCC4 rs1800067 AA or AG genotypes and overall risk of cancer (AA vs. GG: OR=0.998, 95%CI=0.670-1.486, P=0.992; AG vs. GG: OR=0.970, 95%CI=0.888-1.061, P=0.508). A dominant genetic model also did not demonstrate significant association of (AA+AG) genotype carriers with altered risk of overall cancer (OR=0.985, 95%CI=0.909-1.068, P=0.719). In addition, no significant association was observed between A allele of ERCC4 rs1800067 A/G polymorphism and altered cancer risk compared with G allele (OR=0.952, 95%CI=0.851-1.063, P=0.381). Subgroup analysis suggested that AA genotype carriers were significantly associated with decreased risk of glioma compared with wild-type GG genotype individuals (OR=0.523, 95%CI=0.275-0.993, P=0.048). For subgroup of lung cancer, A allele of ERCC4 rs1800067 A/G polymorphism was significantly associated with decreased risk of lung cancer compared with G allele (OR=0.806, 95%CI=0.697-0.931, P=0.003). Conclusions: This meta-analysis indicated that ERCC4 rs1800067 A/G polymorphism might not be associated with risk of overall cancer. However, individuals with the AA genotype were associated with significantly reduced risk of glioma compared with wild-type GG genotype; The A allele was associated with significantly reduced risk of lung cancer compared with G allele. Future large-scale studies performed in multiple populations are warranted to confirm our results.

Hypermethylation and Clinicopathological Significance of RASAL1 Gene in Gastric Cancer

  • Chen, Hong;Pan, Ying;Cheng, Zheng-Yuan;Wang, Zhi;Liu, Yang;Zhao, Zhu-Jiang;Fan, Hong
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.11
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    • pp.6261-6265
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    • 2013
  • Background: Recent studies have suggested that expression of the RAS protein activator like-1 gene (RASAL1) is decreased in gastric carcinoma tissues and cell lines, indicated a role in tumorigenesis and development of gastric cancer. Reduced expression of RASAL1 could result in aberrant increase of activity of RAS signaling pathways in cancer cells. However, the exact mechanism which induces down-regulation of the RASAL1 gene remains unclear. This study aimed to determine the methylation status and regulation of RASAL1 in gastric cancer. Materials and Methods: Using the methylation-specific polymerase chain reaction (MSP), the methylation status of CpG islands in the RASAL1 promoter in gastric cancers and paired adjacent non-cancerous tissues from 40 patients was assessed and its clinicopathological significance was analyzed. The methylation status of RASAL1 in gastric cancer lines MKN-28, SGC-790l, BGC-823, as well as in normal gastric epithelial cell line GES-l was also determined after treatment with a DNA methyltransferase inhibitor, 5-aza-2'-doexycytidine (5-Aza-CdR). RAS activity (GAS-GTP) was assessed through a pull-down method, while protein levels of ERK1/2, a downstream molecule of RAS signaling pathways, were determined by Western blotting. Results: The frequencies of RASAL1 promoter methylation in gastric cancer and paired adjacent non-cancerous tissues were 70% (28/40) and 30% (12/40) respectively (P<0.05). There were significantly correlations between RASAL1 promoter methylation with tumor differentiation, tumor size, invasive depth and lymph node metastasis in patients with gastric cancer (all P<0.05), but no correlation was found for age or gender. Promoter hypermethylation of the RASAL1 gene was detected in MKN-28, SGC-790l and BGC-823 cancer cells, but not in the normal gastric epithelial cell line GES-1. Elevated expression of the RASAL1 protein, a decreased RAS-GTP and p-ERK1/2 protein were detected in three gastric cancer cell lines after treatment with 5-Aza-CdR. Conclusions: Aberrant hypermethylation of the RASAL1 gene promoter frequently occurs in gastric cancer tissues and cells. In addition, the demethylating agent 5-Aza-CdR can reverse the hypermethylation of RASAL1 gene and up-regulate the expression of RASAL1 significantly in gastric cancer cells in vivo. Our study suggests that RASAL1 promoter methylation may have a certain relationship with the reduced RASAL1 expression in gastric cancer.