• Title/Summary/Keyword: inflection points

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A Novel Approach for Gastric Cancer Staging in Elderly Patients Based on the Lymph Node Ratio

  • Park, Joonseon;Jeon, Chul Hyo;Kim, So Jung;Seo, Ho Seok;Song, Kyo Young;Lee, Han Hong
    • Journal of Gastric Cancer
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    • v.21 no.1
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    • pp.84-92
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    • 2021
  • Purpose: To date, no studies have been performed on staging based on the lymph node ratio (LNR) in elderly patients with gastric cancer who may require limited lymph node (LN) dissection due to morbidity and tissue fragility. We aimed to develop a new N staging system using the LNR in elderly patients with gastric cancer. Materials and Methods: The present study included patients aged over 75 years who underwent curative gastrectomy between January 1989 and December 2018. Clinicopathological data including the number of retrieved and metastatic LNs were collected and the LNR values were obtained (LNR = the number of metastatic LNs/the number of retrieved LNs). Eleven LNR groups with intervals of 0.1 were divided into four stages based on the inflection points at which the hazard ratio (HR) increased. Survival analysis was performed to evaluate the prognostic value of the LNR. Results: The four LNR stages included LNR0 (n=364), LNR1 (n=128), LNR2 (n=103), and LNR3 (n=10). In the multivariate analysis, both N staging and LNR staging exhibited significant prognostic values for predicting survival outcomes. However, the incremental change in the hazard ratio (HR) between consecutive stages was greater for the LNR staging than for the N staging (HRs: 1.607, 2.758, and 3.675 for N staging; 1.583, 3.514, and 10.261 for LNR staging). Conclusions: LNR staging is more useful than N staging in predicting the prognosis in elderly patients with gastric cancer and may be used as a complement or alternative to N staging.

[Retracted]Analysis of Minimum Penetrated Depth of Pile bent of IPM Bridge ([논문철회]토압분리형 일체식 교대 교량의 파일벤트에 대한 최소근입깊이 해석)

  • Kim, Hongbae;Kim, Taesu;Park, Jongseo;Han, Heuisoo
    • Journal of the Korean GEO-environmental Society
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    • v.18 no.5
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    • pp.45-53
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    • 2017
  • IPM bridge was developed to revise the problems of IAB bridge by Nam et al, (2016). This research conducted the p-y analysis to examine the parameter traits among the protruded length (H), penetrated length (L) of pile bent and soil conditions. From the results, the maximum bending moment happened in the top segment of pile bent, because it is integrated to the upper structure. Also, the maximum shear force was shown in the boundary of the sand and weathered soil zones according to the analysis soil conditions. The maximum member force and unbraced length is converged when the ratio (L/H) of protruded length (H) and penetrated length (L) is 1.0. The larger material force is happened, if the pile bent is penetrated shallowly compared to the protruded length. The definite inflection points were shown in the horizontal displacement curve from the p-y analysis, also the smaller penetrated length made the curve grade slower.

Recent Advances on MOF-assisted Atmospheric Water Harvesting at Dry Regions (수분 수착 MOF를 이용한 건조한 지역의 대기 중 워터하베스팅 기술의 최근 동향)

  • Geunho Lee;Woochul Song
    • Membrane Journal
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    • v.34 no.1
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    • pp.30-37
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    • 2024
  • As a promising method to address global water scarcity, sorbent-assisted water harvesting from air has shown great potential to deliver drinking water for inlands lacking traditional water sources. In this article, the recent studies of using metal-organic frameworks (MOFs) as sorbents to harvest atmospheric water will be introduced. Compared to the other sorbent materials such as zeolites or silica-based materials, MOFs have shown prospective properties such as the water isotherm inflection points as low as ~10%, which are suitable for harvesting water at dry regions. Due to this property, recently, MOFs have been extensively adopted to develop practical water harvesting devices that can harvest water. Since atmospheric water is accessible anywhere and anytime in the world, this technology is expected to open a new avenue in terms of securing safe water for the future.

A Study of Landscape Architect YoungSun Jung's Theory of Landscape Architecture (조경가 정영선의 조경설계론 연구)

  • Ahn, Myung June
    • Journal of the Korean Institute of Landscape Architecture
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    • v.52 no.3
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    • pp.1-17
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    • 2024
  • This study focuses on the landscape architect Jung YoungSun to examine Korean landscaping. To do so, the research focuses on the artist's thoughts, her and Seoan's works, and related discourse (landscape architects, landscape works, and landscape discourse) up to 2014. Research was conducted through interviews (with Jung and related people), a literature survey, and the analysis of design works. As a result, four inflection points of Jung's landscape architecture career emerged, from the time she was introduced to landscape architecture, trained in it, and entered into practice, to the time she operated an independent office, showing different design trends and the depth of design thinking. In this process, excluding the early learning period, Jung's landscapes were categorized into three categories: contemporary landscapes, gardens, and traditional landscapes. Through these three categories of landscaping activities, Jung's achievements include the importation and internalization of modern landscapes (modern landscape theory), the establishment of her own garden theory and its practice (garden theory), and overcoming of tradition complexes and creative succession (traditional landscape theory). In sum, Jung's landscapes can be summarized as the practice of regionalists and auteurist thinking.

Estimation of the Central Aortic Pulse using Transfer Function and Improvement of an Augmentation Point Detection Algorithm (전달함수를 이용한 대동맥 맥파 추정 및 증강점 검출 알고리즘 개선에 관한 연구)

  • Im, Jae-Joong
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.45 no.3
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    • pp.68-79
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    • 2008
  • Aortic AIx(augmentation index) has been used to measure aortic stiffness quantitatively and even to evaluate ventricular load. However, in order to calculate aortic AIx catheters should be inserted to the subjects' artery, which hampers its clinical usage. To overcome such limitation, aortic AIx has been indirectly calculated by estimating aortic pressure wave from the peripheral arterial pulse by applying transfer functions. In this study, central aortic pressure waves using Millar catheter and radial artery pulse waves using tonometry pressure sensor were measured to establish transfer functions for an estimation of central aortic pressure waves from radial artery pulse waves. Also, an algorithm which detects augmentation point for the calculation of AIx were developed. Developed algorithm for the detection of augmentation point gradually increases the differential order to detect inflection point rather than detects the distinctive point that appears after a specific time. Transfer functions were established using 10th order ARX model and were verified for the stability of the transfer function through residual analysis. Evaluation of an algorithm for the detection of augmentation point were performed by comparing the augmentation points obtained from developed algorithm with the known augmentation points synthesized in various conditions. In addition, developed algorithm for the AIx is proved to provide more accurate results than the ones developed by previous studies. The significance of the study was in two folds. Firstly, the results could provide the basis for the measurement of aortic stiffness using easily-measurable radial artery pulse waves, and secondly, extension of the study may enable the early diagnosis of various vascular diseases.

A Feasibility Study on Using Neural Network for Dose Calculation in Radiation Treatment (방사선 치료 선량 계산을 위한 신경회로망의 적용 타당성)

  • Lee, Sang Kyung;Kim, Yong Nam;Kim, Soo Kon
    • Journal of Radiation Protection and Research
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    • v.40 no.1
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    • pp.55-64
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    • 2015
  • Dose calculations which are a crucial requirement for radiotherapy treatment planning systems require accuracy and rapid calculations. The conventional radiotherapy treatment planning dose algorithms are rapid but lack precision. Monte Carlo methods are time consuming but the most accurate. The new combined system that Monte Carlo methods calculate part of interesting domain and the rest is calculated by neural can calculate the dose distribution rapidly and accurately. The preliminary study showed that neural networks can map functions which contain discontinuous points and inflection points which the dose distributions in inhomogeneous media also have. Performance results between scaled conjugated gradient algorithm and Levenberg-Marquardt algorithm which are used for training the neural network with a different number of neurons were compared. Finally, the dose distributions of homogeneous phantom calculated by a commercialized treatment planning system were used as training data of the neural network. In the case of homogeneous phantom;the mean squared error of percent depth dose was 0.00214. Further works are programmed to develop the neural network model for 3-dimensinal dose calculations in homogeneous phantoms and inhomogeneous phantoms.

Relationship of Pupil's Size and Gaze Frequency for Neuro Sports Marketing: Focusing on Sigma Analysis (뉴로 스포츠 마케팅을 위한 동공 확장과 주시빈도 간의 관계: 시그마 분석법을 적용하여)

  • Ko, Eui-Suk;Song, Ki-Hyeon;Cho, Soo-Hyun;Kim, Jong-Ha
    • Science of Emotion and Sensibility
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    • v.20 no.3
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    • pp.39-48
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    • 2017
  • In order to verify the effectiveness of marketing in the basketball stadium, this study measured and analyzed the gaze frequency and interest when the pupil was expanded by using the eye-tracking technology among various neuro marketing techniques of marketing. To analyze the section where the pupil size get expanded, interval of pupil size was higher than 2.275% (2 sigma data) and higher than 0.135% high (3 sigma data). Overall the valid data was analyzed by inflection points according to gaze frequency. We also analyzed the correlation between overall valid data and the ranges where the pupil size was significantly increased. The result showed that the correlation between overall valid data and pupil size 2 sigma data showed the highest correlation with 0.805. The pupil size 2 sigma data and pupil size 3 sigma data showed a correlation with 0.781, overall the valid data and pupil size 2 sigma data showed a correlation with 0.683. Therefore, it is concluded that, the section where the pupil size was expanded and the section at which gaze frequency is higher in the eye-tracking data were similar. However, the correlation between data of pupil size is determined to be significantly expanded and overall the valid data is decreased.

A Study on the Criteria Establishment for One-way road using AHP (AHP분석을 활용한 일방통행 선정기준 정립에 관한 연구)

  • Park, Je Jin;Kim, Min Chul;Kim, Jae Gon;Ha, Tae Jun
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.16 no.3
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    • pp.39-49
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    • 2017
  • Standards suitable for local conditions on deciding one-way road are desperately required to solve traffic congestions at the backside roads in the old downtown areas which were not designated as a road by urban planning. Therefore, this study intends to re-establish a standard to decide one-way road which is regarded to be of the greatest effect among traffic system control methods in order to control one-way road system more efficiently. Also, this paper suggests a standard for such decision to improve efficiency of using backside roads and expand designation of one-way road. AHP (analytic hierarchy process) was carried out among the traffic experts to find out the factors to decide one-way road system. Its result reveals that importance of causing accident to walking quantity and traffic was high. 10,000 cases out of all the possible scenarios of accident by combining detailed evaluation items and scales were extracted to draw the outcomes of analyzing the scenarios, which were schematized in a graph. As a result, division by three sections of point of inflection was verified into $1{\leq}$ section A<1.91, 1.9$1{\leq}$ section B<2.08, and $2.08{\leq}$ section C<3. In other words, priority of deciding one-way road should be given to section C, the highest total point, while posterior to section A, where relatively low points are distributed. The standard on deciding one-way road suggested in this paper may be used for designating one-way road and basic data to re-establish the relevant system in the future.

Fermentative Water Purification based on Bio-hydrogen (생물학적 수소 발효를 통한 수처리 시스템)

  • Lee, Jung-Yeol;Chen, Xue-Jiao;Min, Kyung-Sok
    • Journal of Korean Society on Water Environment
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    • v.27 no.6
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    • pp.926-931
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    • 2011
  • Among various techniques for hydrogen production from organic wastewater, a dark fermentation is considered to be the most feasible process due to the rapid hydrogen production rate. However, the main drawback of it is the low hydrogen production yield due to intermediate products such as organic acids. To improve the hydrogen production yield, a co-culture system of dark and photo fermentation bacteria was applied to this research. The maximum specific growth rate of R. sphaeroides was determined to be $2.93h^{-1}$ when acetic acid was used as a carbon source. It was quite high compared to that of using a mixture of volatile fatty acids (VFAs). Acetic acid was the most attractive to the cell growth of R. sphaeroides, however, not less efficient in the hydrogen production. In the co-culture system with glucose, hydrogen could be steadily produced without any lag-phase. There were distinguishable inflection points in the accumulation of hydrogen production graph that resulted from the dynamic production of VFAs or consumption of it by the interaction between the dark and photo fermentation bacteria. Lastly, the hydrogen production rate of a repeated fed-batch run was $15.9mL-H_2/L/h$, which was achievable in the sustainable hydrogen production.

A Study on the Expansion of Secondary Battery Manufacturing Technology through the Scale of V4 and Energy Platform (V4와 에너지 플랫폼 규모화를 통한 2차 전지 제조 기술 확대 방안)

  • Seo, Dae-Sung
    • Journal of Industrial Convergence
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    • v.20 no.10
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    • pp.87-94
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    • 2022
  • This paper seeks to raise inflection points of battery manufacturing bases in Korea in the V4 region through the reorganization of new industrial technologies in accordance with ESG. As a result, the global supply chain market is cut off. The Russian-Ukraine war and the U.S.-China hegemony are competing in the economic crisis caused by COVID-19. It is showing diversification of new suppliers in an environment where mineral, grain procurement, gas, and even wheat imports from China and Russia are not possible. As a protective glocal, this area is used as a buffer zone(Pro-Russia, Hungary). to an isolated zone(anti-Russia, Poland) by war. In this paper, economic growth is expected to slow further due to the EU tapering period and high inflation in world countries. Due to these changes, the conversion of new tech industry and the contraction of Germany's structure due to energy supply may lose the driving force for economic growth over the past 20 years. This is caused by market disconnection(chasm) in the nominal indicators in this area. On the other hand, Korea should actively develop into the V4 area as an energy generation export (nuclear and electric hydrogen generation) area as a bypass development supply area due to the imbalance in the supply chain of rare earth materials that combines AI. By linking this industry, the energy platform can be scaled up and reliable supply technology (next generation BT, recycling technology) in diversification can be formed in countries around the world. This paper proves that in order to overcome the market chasm caused by the industries connection, new energy development and platform size can be achieved and reliable supply technology (next-generation battery and recycling technology, Low-cost LFP) can be diversified in each country.