• Title/Summary/Keyword: Henry problem

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Development of a Visual-Basic based Two-Dimensional Finite-Difference Density-Coupled Flow Numerical Code for Simulating Saltwater Intrusion (해수침투 모의를 위한 Visual Basic 기반 2차원 유한차분 밀도 결합 흐름 모델 개발)

  • Chang, Sun Woo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.37 no.6
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    • pp.973-980
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    • 2017
  • The purpose of this study is to develop VDFT (Visual Basic based Density-coupled Flow and Transport), a numerical modeling code used to simulate density coupled flow equations used to simulate seawater intrusion in a two dimensional finite difference method. The VDFT code has the advantage of being intuitive and simple to use and has the advantage of utilizing the EXCEL Visual Basic platform, which is widely used for general business purposes. Generally, code developed for numerical simulation can be verified through representative example models called benchmark problem. In this study, we verified the VDFT code using benchmark problem called Henry Problem and Modified Henry Problem as well as two laboratory test data. The results of this study are analyzed the importance of each benchmark problems, validated VDFT code compared to those problems. In conclusion, the possibility of using VDFT code is diagnosed and the direction of future research is suggested.

Retrospective Review of Magnetic Resonance Imaging of the Lumbosacral Spine: Are We Overinvestigating?

  • Khanduja, Suchit;Loomba, Vivek;Salama-Hannah, Joseph;Upadhyay, Aman;Khanduja, Neha;Chauhan, Gaurav
    • Neurospine
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    • v.15 no.4
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    • pp.383-387
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    • 2018
  • Objective: Lower back pain (LBP) is a worldwide health problem, and magnetic resonance imaging (MRI) is a common modality used to aid in its diagnosis. Although specific guidelines for assessing the necessity of MRI usage exist, the use of MRI as the initial imaging method for LBP seems to be more common than necessary in general practice. Methods: We conducted a retrospective chart review of 313 patients who had undergone MRI of the lumbosacral spine during 2014-2015. We recorded and compared various factors, including age, sex, body mass index, current smoking status, race, symptoms, MRI findings, and progression to surgery within the next year. All rates were compared according to whether the MRI results showed radiographically significant findings (MRI-positive) or not (MRI-negative) using the chi-square or Fisher exact tests (if the expected cell count was <5). All analyses were performed using SAS version 9.4. Results: There were no statistically significant differences in the rates of each symptom between the MRI-positive and MRI-negative groups, which accounted for 58.5% (183 of 313) and 41.5% (130 of 313) of the MRIs, respectively. The difference in the rate of surgery in the next year (18% among MRI-positive patients and 8.5% among MRI-negative patients) was found to be statistically significant (p<0.05). Conclusion: Based on our findings, 41.5% of patients underwent lumbar MRI unnecessarily and 81% of patients with positive MRIs did not have surgery within the next year. Further physician training is needed to avoid unnecessary investigations and expenditures.

A Study on the Reforming Method of the Rural Land Regulations in the North Korea;Focused on the Public Land Lease from Henry George's Theory (북한 농촌의 토지제도 개혁 방안 연구;헨리 조지(Henry George)의 이론을 적용한 '토지 공공 임대제'를 중심으로)

  • Park, Chang-Soo
    • Journal of Agricultural Extension & Community Development
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    • v.9 no.1
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    • pp.43-60
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    • 2002
  • Recently the North Korea has been suffered from the grain shortage, and the fundamental reason was in the socialistic land regulations and collective production which restrain farmers' labor desire. So one of the key in solve the problem may be in the reformation of the socialistic land regulations and collective production, however, the capitalistic land regulations may not work as the reformational alternative in the North Korea. The third alternative for land should consider efficiency and equality of reformation itself as well as environmental problems. The purpose of the study was to discuss the possible application of the Public Land Lease from Henry $George(1839{\sim}1897)'s$ theory. The basic idea of the Public Land Lease was that the government has the right of sentence and the right of profit for the land, and the individual has the right of use for the land. Under the Public Land Lease, the individual must pay the land rent for the period of the use for land, and must return the land when the contract is over. If the North Korea's rural land regulations reformed into the Public Land Lease, it would be the first reformational model beyond china.

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Henry gas solubility optimization for control of a nuclear reactor: A case study

  • Mousakazemi, Seyed Mohammad Hossein
    • Nuclear Engineering and Technology
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    • v.54 no.3
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    • pp.940-947
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    • 2022
  • Meta-heuristic algorithms have found their place in optimization problems. Henry gas solubility optimization (HGSO) is one of the newest population-based algorithms. This algorithm is inspired by Henry's law of physics. To evaluate the performance of a new algorithm, it must be used in various problems. On the other hand, the optimization of the proportional-integral-derivative (PID) gains for load-following of a nuclear power plant (NPP) is a good challenge to assess the performance of HGSO. Accordingly, the power control of a pressurized water reactor (PWR) is targeted, based on the point kinetics model with six groups of delayed-neutron precursors. In any optimization problem based on meta-heuristic algorithms, an efficient objective function is required. Therefore, the integral of the time-weighted square error (ITSE) performance index is utilized as the objective (cost) function of HGSO, which is constrained by a stability criterion in steady-state operations. A Lyapunov approach guarantees this stability. The results show that this method provides superior results compared to an empirically tuned PID controller with the least error. It also achieves good accuracy compared to an established GA-tuned PID controller.

Application of Screening Technology for Capture of Hydrogen Sulfide Using Ionic Liquids (이온성 액체의 황화수소의 포집을 위한 스크리닝 기법의 활용)

  • Han, Sangil;Lee, Bong-Seop
    • Journal of Industrial Technology
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    • v.39 no.1
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    • pp.41-45
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    • 2019
  • Hydrogen sulfide ($H_2S$) is mainly produced along with methane and hydrocarbons in many gas fields as well as hydrodesulfurization processes of crude oils containing sulfur compounds and the emission of $H_2S$ has a considerable effect on both environmental problem and human health aspects due to formation of, e.g. acid rain and smog. In recent years, ionic liquids (ILs) have been proposed as the most promising solvents for $CO_2$ and hazardous pollutants capture, such as $H_2S$ and sulfur dioxide ($SO_2$). In this work, we demonstrate the use of the predictive COSMO-SAC model for the prediction of Henry's law constant of $H_2S$ in ILs. Furthermore, the method is used to screen for potential IL candidates for $H_2S$ capture from a set of 2,624 ILs formed from 82 cations and 32 anions. The effects of cation on the Henry's law constant of $H_2S$ such as (i) the variation of the alkyl chain length on cation, (ii) the substituent of methyl group ($-CH_3$) for H in C(2) position and (iii) the change of ring structure for cation family are clearly predicted by COSMO-SAC model.

An Ensemble Fingerprint Classification System Using Changes of Gradient of Ridge (융선 기울기의 변화량을 이용한 앙상블 지문분류 시스템)

  • Yoon, Kyung-Bae;Park, Chang-Hee
    • Journal of the Korean Institute of Intelligent Systems
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    • v.13 no.5
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    • pp.545-551
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    • 2003
  • Henry System which is a traditional fingerprint classification model is difficult to apply to a modem Automatic Fingerprint Identification System (AFIS). To tackle this problem, this study is to apply algorithm for an An Ensemble Fingerprint Classroom System using changes of gradient of ridge in order to improve precise joining speed of a large volume of database. The existing classification system, Henry System, is useful in a captured fingerprint image of core point and delta point using paper and ink. However, the Henry System is unapplicable in modem Automatic Fingerprint Identification System (AFIS) because of problems such as size of input sensor and way of input. This study is to suggest an Ensemble Fingerprint Classroom System which can classify 5 basic patterns of Henry System in uncaptured delta image using changes of gradient of ridge. The proposed fingerprint classification technique will make an improvement of precise joining speed by reducing data volume.

Considering Issues of Vision in Panoptical Representation: Bentham, Bender, Fried, and Mayhew (파놉티콘적 재현에 나타난 시각성의 여러 측면들: 벤쌈, 벤더, 프리드, 메이휴)

  • Shin, Hi-Sup
    • The Journal of Art Theory & Practice
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    • no.7
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    • pp.189-240
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    • 2009
  • This essay aims to develop a critical approach of interpretation in examining the panoptical condition of representation that is said to permeate the tradition of modern realism in novels and paintings. In defining this approach, I am interested in the problem or inability of panoptical representation to tell a coherent story of solitude(solitary confinement, isolation, self-absorption, etc.) in a range of texts from prison documents to paintings and novels, and also what might occasion such an inability including social, material, or stylistic contradictions and conflicting epistemological angles. This task potentially anticipates a trajectory of readings and investigations that cuts through the history of panoptical representation, which is outside the scope of this essay. In this writing, I will engage in a series of debates with what I consider as major theories and views of panoptical representation offered by Jeremy Bentham, John Bender, and Michael Fried. Based on this, I will formulate a conceptual or methodological frame of discourse that would envisage an anti-panoptical approach of interpretation. As an attempt to validate this formulation, I will offer a reading of Henry Mayhew's Criminal Prisons of London and Scenes of Prison Life(1862), a case of panoptical representation that produces a peculiar sense of ambivalence while accounting for sites of penal solitude.

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A Critical Study on Colin Rowe's 'Transparency' - Focusing on the Analysis of the meaning of 'Time and Simultaneity' implicated in 'Transparency' - (콜린 로우(Colin Rowe) '투명성(transparency) 이론'의 비판적 고찰 - 투명성에 내재된 시간 개념의 분석을 중심으로 -)

  • Kweon, Tae-Ill
    • Journal of architectural history
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    • v.15 no.2
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    • pp.115-136
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    • 2006
  • Colin Rowe's 'Transparency' is one of core ideas applied to 20th Modern Architecture. It implies not only an optical characteristic, the perfectly clear, but also a broader spacial order, a simultaneous perception of different spacial locations. The former connected with physical attribute itself, and the latter deeply with the metaphorical idea of time, 'Simultaneity', embodying a new spacial quality. However, If we analyze the meaning of "Simultaneity" implicated in "Transparency" with the perspective of Henry Bergson's "Duration", there would be only little possibility as a solution to the problem of embodying a new spacial quality in architecture. As such a question emerging, this paper attempts to point out the problem of Colin Rowe's idea, "Simultaneity", and suggest a new architectural design method to overcome its inconsistency by interpretation and application of Bergson's "Image and Rhythm".

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Municipal solid waste management in Aba, Nigeria: Challenges and prospects

  • Ezechi, Ezerie Henry;Nwabuko, Chima George;Enyinnaya, Ogbonna Chidi;Babington, Chibunna John
    • Environmental Engineering Research
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    • v.22 no.3
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    • pp.231-236
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    • 2017
  • Solid waste disposal and management is a critical problem in Nigeria. Annually, a huge quantity of municipal solid waste is generated in Aba. Municipal solid waste disposal in Aba poses severe challenge to environmental safety, public health and welfare of citizens. The situation is made worse by the indiscriminate dumping of refuse at roadsides, streets, waterways and empty lands. The impact of this waste management practice in Aba is environmental deterioration. Efforts to improve waste management in Aba have not recorded significant success. This paper therefore aims to highlight the challenges facing the waste management sector in Aba and proffer solutions on how to improve the sector.

NPP Site Selection : A Systems Engineering Approach (시스템즈 엔지니어링 기법을 이용한 원자력발전소 부지 선정 방법에 대한 연구)

  • Pwani, Henry;Kamanja, Florah;Zolkaffly, Zulfakar;Jung, J.C.
    • Journal of the Korean Society of Systems Engineering
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    • v.9 no.1
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    • pp.55-63
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    • 2013
  • Nuclear power plant site selection is a complex process and its successful completion is a critical milestone in the NPP development cycle. Proper siting of NPP will ensure public health and safety, environmental conservation, reduced project failure risks and a smooth NPP development process among other benefits. The objective of this paper is to demonstrate the application of systems engineering to the problem of NPP siting in Kenya. The siting process demonstrated in this paper includes stakeholder need analysis where stakeholders are identified and their needs concerning NPP site are elicited and converted into system functional requirements. A value model is then developed and potential sites iteratively subjected to three types of criteria i.e. exclusionary criteria, avoidance criteria and suitability criteria. This process is used to identify the candidate sites. An additive value model; multiple objectives Decision Analysis (MODA) is then used to calculate candidate solutions values. The site with the highest solution value score is selected. Sensitivity studies using different criterion weight sets (thereby reflecting different viewpoints) can be conducted to assess their effect on the selection of a preferred site and thereby lend additional credibility to the decision process.