• Title/Summary/Keyword: Inferior Selection

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Selection of Cluster Hierarchy Depth and Initial Centroids in Hierarchical Clustering using K-Means Algorithm (K-Means 알고리즘을 이용한 계층적 클러스터링에서 클러스터 계층 깊이와 초기값 선정)

  • Lee, Shin-Won;An, Dong-Un;Chong, Sung-Jong
    • Journal of the Korean Society for information Management
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    • v.21 no.4 s.54
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    • pp.173-185
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    • 2004
  • Fast and high-quality document clustering algorithms play an important role in providing data exploration by organizing large amounts of information into a small number of meaningful clusters. Many papers have shown that the hierarchical clustering method takes good-performance, but is limited because of its quadratic time complexity. In contrast, with a large number of variables, K-means has a time complexity that is linear in the number of documents, but is thought to produce inferior clusters. In this paper, Condor system using K-Means algorithm Compares with regular method that the initial centroids have been established in advance, our method performance has been improved a lot.

Development of Efficient Curing Sheet for Thermal Insulation Curing of Concrete in Cold Weather

  • Han, Cheon-Goo;Son, Myung-Sik;Choi, Hyun-Kyu
    • Journal of the Korea Institute of Building Construction
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    • v.12 no.3
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    • pp.291-298
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    • 2012
  • For cold weather concreting, frost damage at early age is generated in the concrete, and problems such as delaying of setting and hardening and lowering of strength manifestation emerge due to the low outside air temperature at the early stage of pouring, making the selection of an effective curing method critically important. Unfortunately, the tent sheet currently used as the curing film for heating insulation at work sites, not only has the problems of inferior permeability and extremely deteriorated airtightness, but a phenomenon of continuous fracturing is also generated along the direction of fabric of the material itself, presenting difficult circumstances for maintaining adequate curing temperature. The aim of this study was to develop an improved bubble sheet type curing film for heating insulation of cold weather concrete by combining mesh-tarpaulin, which has excellent tension properties, with bubble sheet, which offers superior insulation performance. The analysis showed that the improved curing film in which BBS1 is stacked to MT was a suitable replacement for curing films currently in use, as it has better permeability, tension property, and insulation performance than the T type film used at work sites today.

A Study on Cluster Hierarchy Depth in Hierarchical Clustering (계층적 클러스터링에서 분류 계층 깊이에 관한 연구)

  • Jin, Hai-Nan;Lee, Shin-won;An, Dong-Un;Chung, Sung-Jong
    • Proceedings of the Korea Information Processing Society Conference
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    • 2004.05a
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    • pp.673-676
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    • 2004
  • Fast and high-quality document clustering algorithms play an important role in providing data exploration by organizing large amounts of information into a small number of meaningful clusters. In particular, hierarchical clustering provide a view of the data at different levels, making the large document collections are adapted to people's instinctive and interested requires. Many papers have shown that the hierarchical clustering method takes good-performance, but is limited because of its quadratic time complexity. In contrast, K-means has a time complexity that is linear in the number of documents, but is thought to produce inferior clusters. Think of the factor of simpleness, high-quality and high-efficiency, we combine the two approaches providing a new system named CONDOR system [10] with hierarchical structure based on document clustering using K-means algorithm to "get the best of both worlds". The performance of CONDOR system is compared with the VIVISIMO hierarchical clustering system [9], and performance is analyzed on feature words selection of specific topics and the optimum hierarchy depth.

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The Neuroanatomy and Psychophysiology of Attention (집중의 신경해부와 정신생리)

  • Lee, Sung-Hoon;Park, Yun-Jo
    • Sleep Medicine and Psychophysiology
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    • v.5 no.2
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    • pp.119-133
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    • 1998
  • Attentional processes facilitate cognitive and behavioral performance in several ways. Attention serves to reduce the amount of information to receive. Attention enables humans to direct themselves to appropriate aspects of external environmental events and internal operations. Attention facilitates the selection of salient information and the allocation of cognitive processing appropriate to that information. Attention is not a unitary process that can be localized to a single neuroanatomical region. Before the cortical registration of sensory information, activation of important subcortical structures occurs, which is called as an orienting response. Once sensory information reaches the sensory cortex, a large number of perceptual processes occur, which provide various levels of perceptual resolution of the critical features of the stimuli. After this preattentional processing, information is integrated within higher cortical(heteromodal) systems in inferior parietal and temporal lobes. At this stage, the processing characteristics can be modified, and the biases of the system have a direct impact on attentional selection. Information flow has been traced through sensory analysis to a processing stage that enables the new information to be focused and modified in relation to preexisting biases. The limbic and paralimbic system play significant roles in modulating attentional response. It is labeled with affective salience and is integrated according to ongoing pressures from the motivational drive system of the hypothalamus. The salience of information greatly influences the allocation of attention. The frontal lobe operate response selection system with a reciprocal interaction with both the attention system of the parietal lobe and the limbic system. In this attentional process, the search with the spatial field is organized and a sequence of attentional responses is generated. Affective, motivational and appectitive impulses from limbic system and hypothalamus trigger response intention, preparation, planning, initiation and control of frontal lobe on this process. The reticular system, which produces ascending activation, catalyzes the overall system and increases attentional capacity. Also additional energetic pressures are created by the hypothalamus. As psychophysiological measurement, skin conductance, pupil diameter, muscle tension, heart rate, alpha wave of EEG can be used. Event related potentials also provide physiological evidence of attention during information process. NI component appears to be an electrophysiological index of selective attention. P3 response is developed during the attention related to stimulus discrimination, evaluation and response.

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Development of nutrigenomic based precision management model for Hanwoo steers

  • Chandima Gajaweera;Dong Hun Kang;Doo Ho Lee;Yeong-Kuk Kim;Bo Hye Park;Sun Sik Chang;Ui Hyung Kim;Seung Hwan Lee;Ki Yong Chung
    • Journal of Animal Science and Technology
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    • v.65 no.3
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    • pp.596-610
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    • 2023
  • Focusing high marble deposition, Hanwoo feedlot system uses high-energy diet over the prolonged fattening period. However, due to the individual genetic variation, around 40% of them are graded into inferior quality grades (QG), despite they utilized the same resources. Therefore, focusing on development of a nutrigenomic based precision management model, this study was to evaluated the response to the divergent selection on genetic merit for marbling score (MS), under different dietary total digestible nutrient (TDN) levels. Total of 111 calves were genotyped and initially grouped according to estimated breeding value (high and low) for marbling score (MS-EBV). Subsequently, managed under two levels of feed TDN%, over the calf period, early, middle, and final fattening periods following 2 × 2 factorial arrangement. Carcasses were evaluated for MS, Back fat thickness (BFT) and Korean beef quality grading standard. As the direct response to the selection was significant, the results confirmed the importance of initial genetic grouping of Hanwoo steers for MS-EBV. However, dietary TDN level did not show an effect (p > 0.05) on the MS. Furthermore, no genetic-by-nutrition interaction for MS (p > 0.05) was also observed. The present results showed no correlation response on BFT (p > 0.05), which indicates that the selection based on MS-EBV can be used to enhance the MS without undesirable effect on BFT. Ultimate turnover of the Hanwoo feedlot operation is primarily determined by the QGs. The present model shows that the initial grouping for MS-EBV increased the proportion of carcasses graded for higher QGs (QG1++ and QG1+) by approximately 20%. Moreover, there appear to be a potential to increase the proportion of QG 1++ animals among the high-genetic group by further increasing the dietary energy content. Overall, this precision management strategy suggests the importance of adopting an MS based initial genetic grouping system for Hanwoo steers with a subsequent divergent management based on dietary energy level.

Job Selection, Separation, and Wage Level of SME Workers: based on a Follow-up Survey on Recent College Graduates (중소기업 취업자의 직장선택과 이동 그리고 임금 수준 분석)

  • Park, Jae-Min
    • The Journal of the Korea Contents Association
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    • v.10 no.9
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    • pp.387-398
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    • 2010
  • Recently SMEs(small and medium enterprises) in Korea have experienced severe labor shortages. In particular, college graduates avoiding SMEs are widely spotted. According to previous studies, the main causes of the evasion by college graduates are the inferior working environment and low wages. Some studies also state that SME workers experience discrimination. However, most studies have focused only on unemployment issues of the young graduates. In this research, the results of follow-up surveys on the employment status and job conditions of recent college graduates was linked as a panel data, and the performance of the graduates was analyzed. Based on the analysis, we found college graduates who are employed SMEs are likely to have their initial career fixed to the SMEs. Second, the job separation records of the young SME workers does not show positive labor market performances such as upward movements or wage increases, and the process itself turned out to be entailed frequent separation. Third, the inferior wage level at SMEs and the fact that this effect is cumulatively amplified has been a key factor for evading SMEs. Thus, it is difficult to say that the early-stage careers in SMEs are constructive in future career development. On the contrary, the early careers at SMEs result in lower labor market outcomes, and frequent job separation.

Liver Cut Method Using 4 Points for Hepatic Volumerty at MDCT Image (MDCT 영상에서 간 체적 계산을 위한 4 점 이용 간 분할 방법)

  • Seo, Jeong-Joo;Cho, Baik-Hwan;Park, Jong-Won
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.47 no.1
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    • pp.17-24
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    • 2010
  • This paper proposed the method to separate a liver into left and right liver lobes for exact volumetry of the river graft at abdominal MDCT(Multi-Detector Computed Tomography) image before living donor liver transplantation. On the image of segmented liver, 4 points(the middle point of Inferior Vena Cava, a point of Middle Hepatic Vein, a point of Portal Vein, a middle point of gallbladder fossa) are selected. A liver is separated into left and right liver lobes on the basis of the 4 points. The volume and ratio of the river graft are estimated. The volume estimated using 4 points and the manual volume that radiologist processed and estimated are compared with the weight measured during surgery to support proof of the exact volumetry. After selection the 4 points, the time involved in separation a liver into left and right river lobe and volumetry of them is measured for confirmation that the algorithm can be used on real time during surgery. This study progressed to ensure donor's and recipient's safe who will undergo the liver transplantation.

Preoperative Prediction for Early Recurrence Can Be as Accurate as Postoperative Assessment in Single Hepatocellular Carcinoma Patients

  • Dong Ik Cha;Kyung Mi Jang;Seong Hyun Kim;Young Kon Kim;Honsoul Kim;Soo Hyun Ahn
    • Korean Journal of Radiology
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    • v.21 no.4
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    • pp.402-412
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    • 2020
  • Objective: To evaluate the performance of predicting early recurrence using preoperative factors only in comparison with using both pre-/postoperative factors. Materials and Methods: We retrospectively reviewed 549 patients who had undergone curative resection for single hepatcellular carcinoma (HCC) within Milan criteria. Multivariable analysis was performed to identify pre-/postoperative high-risk factors of early recurrence after hepatic resection for HCC. Two prediction models for early HCC recurrence determined by stepwise variable selection methods based on Akaike information criterion were built, either based on preoperative factors alone or both pre-/postoperative factors. Area under the curve (AUC) for each receiver operating characteristic curve of the two models was calculated, and the two curves were compared for non-inferiority testing. The predictive models of early HCC recurrence were internally validated by bootstrap resampling method. Results: Multivariable analysis on preoperative factors alone identified aspartate aminotransferase/platelet ratio index (OR, 1.632; 95% CI, 1.056-2.522; p = 0.027), tumor size (OR, 1.025; 95% CI, 0.002-1.049; p = 0.031), arterial rim enhancement of the tumor (OR, 2.350; 95% CI, 1.297-4.260; p = 0.005), and presence of nonhypervascular hepatobiliary hypointense nodules (OR, 1.983; 95% CI, 1.049-3.750; p = 0.035) on gadoxetic acid-enhanced magnetic resonance imaging as significant factors. After adding postoperative histopathologic factors, presence of microvascular invasion (OR, 1.868; 95% CI, 1.155-3.022; p = 0.011) became an additional significant factor, while tumor size became insignificant (p = 0.119). Comparison of the AUCs of the two models showed that the prediction model built on preoperative factors alone was not inferior to that including both pre-/postoperative factors {AUC for preoperative factors only, 0.673 (95% confidence interval [CI], 0.623-0.723) vs. AUC after adding postoperative factors, 0.691 (95% CI, 0.639-0.744); p = 0.0013}. Bootstrap resampling method showed that both the models were valid. Conclusion: Risk stratification solely based on preoperative imaging and laboratory factors was not inferior to that based on postoperative histopathologic risk factors in predicting early recurrence after curative resection in within Milan criteria single HCC patients.

Radiographic evaluation of the symphysis menti as a donor site for an autologous bone graft in pre-implant surgery

  • Bari, Roberto Di;Coronelli, Roberto;Cicconetti, Andrea
    • Imaging Science in Dentistry
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    • v.43 no.3
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    • pp.135-143
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    • 2013
  • Purpose: This study was performed to obtain a quantitative evaluation of the cortical and cancellous bone graft harvestable from the mental and canine regions, and to evaluate the cortical vestibular thickness. Materials and Methods: This study collected cone-beam computed tomographic (CBCT) images of 100 Italian patients. The limits of the mental region were established: 5 mm in front of the medial margin of each mental foramen, 5 mm under the apex of each tooth present, and above the inferior mandibular cortex. Cortical and cancellous bone volumes were evaluated using SimPlant software (SimPlant 3-D Pro, Materialize, Leuven, Belgium) tools. In addition, the cortical vestibular thickness (minimal and maximal values) was evaluated in 3 cross-sections corresponding to the right canine tooth (3R), the median section (M), and the left canine tooth (3L). Results: The cortical volume was $0.71{\pm}0.23mL$ (0.27-1.96 mL) and the cancellous volume was $2.16{\pm}0.76mL$ (0.86-6.28 mL). The minimal cortical vestibular thickness was $1.54{\pm}0.41mm$ (0.61-3.25 mm), and the maximal cortical vestibular thickness was $3.14{\pm}0.75mm$ (1.01-5.83 mm). Conclusion: The use of the imaging software allowed a patient-specific assessment of mental and canine region bone availability. The proposed evaluation method might help the surgeon in the selection of the donor site by the comparison between bone availability in the donor site and the reconstructive exigency of the recipient site.

A Clinical Application with the Principle of Hanging Point In the Sling Exercise Therapy (슬링운동치료에서 Hanging Point의 원리와 임상적 적용)

  • Kim, Suhn-Yeop;Kim, Taek-Yean;Park, Sung-Jin
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.9 no.2
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    • pp.25-45
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    • 2003
  • Sling exercise treatment(S-E-T) is a therapeutic exercise based on scientific studies for the purpose of treating musculoskeletal or neurological disorders thereby improving strength, endurance, and skills for sensory-motor integration. Exercise resistance and intensity can be modified in various ways by changing the length of rope, patient position, therapist's manual resistance, and using elastic rope. The therapist can also progress to successively higher levels of exercise resistance and intensity by changing the position of the hanging point: the subject of this article. In brief, there are three axial components in S-E-T; hanging point, motor axis, and suspension point. The hanging point can be changed in several ways in relation to the joint; axial, superior, inferior, medial, and posterior hanging points. The position of the hanging point affects the amount of load on agonist and antagonist muscles as well as on the range of motion. To create an advanced exercise program, selection of hanging point can be two-dimensional such as superior-lateral or anterior-medial. Therapists, therefore, can freely but carefully select the best hanging point based on the purpose of the exercise and their level of knowledge in S-E-T.

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