Development of Polymer Properties Prediction System for Operation of PE Reactor

A-Ram Seong,Daegeun Ha,Moon-Ki Cho 제어로봇시스템학회 2019 제어로봇시스템학회 국제학술대회 논문집 Vol.2019 No.10

Efficient operation of the polyethylene (PE) process is greatly dependent on the correct prediction or estimation of the properties including melt index, density and production rate. However, direct measurement of resin property has limitation due to cost of measuring equipment and long measurement period. Although product drops are made every few minutes to remove resin from a reactor, they vary in size and do not occur at a precisely known frequency. These problems make the difficulty of the real-time control of the product quality and lead to yield off-spec products, resulting in economic losses. For this reason, resin property in polyethylene process must be inferred or calculated from other process variables that are directly measured. The combination of online and offline measurement equipment information based on the process model not only improves the measurement performance of the quality variable but also contributes to the control performance of the product property. In this study, we developed some calculation methods based on material and energy balance around the reactor can be used to estimate the resin property in a PE process.

시트 물성 기반 착좌 안락감 추정 방법 개발

이승훈(Seunghoon Lee),정하영(Hayoung Jung),정규호(Gyuho Chung),유희천(Heecheon You) 대한인간공학회 2019 대한인간공학회 학술대회논문집 Vol.2019 No.10

Objective: The present study developed a seating comfort prediction method using the material properties of seat. Background: Different material properties are applied to each seating area to improve seating comfort such as cushioning and supportability. Prediction models of seating comfort is needed for a seat made of a combination of various material properties. Method: A group of 33 adults (7 females and 26 males) was recruited to the subjective seating comfort evaluation experiment in the present study. The material properties of 12 seats were measured by a multi-segment static load tester developed in the present study. Seating comfort prediction models were developed using data of subjective seating comfort evaluation and material propertie collected in the experiment. Results: The adjusted R<SUP>2</SUP> values of the developed models were identified as 75.3% ± 2.9% for cushion and 74.8% ± 2.0% for backrest. Conclusion: The prediction models which can predict the seating comfort of a seat with a combination of seat material properties were developed in the study. Application: The prediction models can be used to examine the adequacy of seat material properties at the early stage of seat development.

Prediction model for the hydration properties of concrete

추인엽,Muhammad Nasir Amin,김진근 사단법인 한국계산역학회 2013 Computers and Concrete, An International Journal Vol.12 No.4

This paper investigates prediction models estimating the hydration properties of concrete, such as the compressive strength, the splitting tensile strength, the elastic modulus,and the autogenous shrinkage. A prediction model is suggested on the basis of an equation that is formulated to predict the compressive strength. Based on the assumption that the apparent activation energy is a characteristic property of concrete, a prediction model for the compressive strength is applied to hydration-related properties. The hydration properties predicted by the model are compared with experimental results, and it is concluded that the prediction model properly estimates the splitting tensile strength, elastic modulus, and autogenous shrinkage as well as the compressive strength of concrete.

Using Machine Learning Algorithms for Housing Price Prediction: The Case of Islamabad Housing Data

Imran, Imran,Zaman, Umar,Waqar, Muhammad,Zaman, Atif Institute of Information Science and Technology 2021 Soft computing and machine intelligence Vol.1 No.1

House price prediction is a significant financial decision for individuals working in the housing market as well as for potential buyers. From investment to buying a house for residence, a person investing in the housing market is interested in the potential gain. This paper presents machine learning algorithms to develop intelligent regressions models for House price prediction. The proposed research methodology consists of four stages, namely Data Collection, Pre Processing the data collected and transforming it to the best format, developing intelligent models using machine learning algorithms, training, testing, and validating the model on house prices of the housing market in the Capital, Islamabad. The data used for model validation and testing is the asking price from online property stores, which provide a reasonable estimate of the city housing market. The prediction model can significantly assist in the prediction of future housing prices in Pakistan. The regression results are encouraging and give promising directions for future prediction work on the collected dataset.

Sub-level Classification and Prediction System of Fully Weathered Red Sandstone Rock Mass Based on Physical Property Indices

Haiyan Xu,Zimeng Shao,Zhijie Wang,Libin Cai,Zhen Li,Xinzheng Jiang 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.3

This paper intends to obtain a sub-level classification of fully weathered red sandstone rock mass during the Cretaceous period based on physical property indices. An automatic prediction system for mechanical properties of rock mass is also established in which the values of rock mass grade and mechanical properties can be returned when physical indices are given. In this study, water content, relative compaction, and fine content, which are relatively easy to measure on tunnel sites, are selected as physical property indices, while cohesion, internal friction angle, and compression modulus, which affect mechanical strength, are taken as mechanical indices. For the convenience of analysis, rock mass of different physical states is divided into 18 different combinations based on the results of lab tests and rock mass stability of each state is evaluated using a stability evaluation criterion we put forward. The numerical simulation of tunnel excavation is further carried out for determining the sub-level classification. A decision tree model is applied for further studying the relationship between physical and mechanical indices to ensure accurate prediction. The result shows that the prediction system works with high accuracy and can be used for engineering reference for fully weathered red sandstone rock mass.

Machine learning for prediction of atom-projected properties

진영록,Lee Jaekwang 한국물리학회 2023 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.83 No.4

The application of machine learning (ML) and deep learning techniques in materials science has revolutionized the process of material design and property prediction. ML models have been widely used to accurately predict various material properties, such as formation energy, band gap, and bulk modulus. However, interpreting the individual contribution of each atom to the overall material properties has remained an open challenge. In this paper, we introduce an atom-projected neural network (APNN) model to directly predict the individual contributions of each atom to the material properties. We demonstrate that our model achieves a great performance comparable to that of other graph-based neural networks while providing signifcantly improved interpretability. The proposed model has great potential for further applications in materials science, such as predicting thermal conductivity or bulk modulus, enabling researchers to understand how individual atoms contribute to the observed properties.

ISO 9613-2를 이용한 철도 환경소음 예측 모델 개선에 관한 연구

장승호 ( Seungho Jang ),고효인 ( Hyo-in Koh ),홍지영 ( Jiyoung Hong ) 한국환경영향평가학회 2017 환경영향평가 Vol.26 No.1

철도 소음의 환경영향평가 업무에 있어서 소음도에 대한 정확한 예측이 중요하지만, 국내에서는 overall 소음도의 거리별 측정을 통한 경험식이 근사적으로 이용되고 있다. 본 논문에서는 소음원과 소음전파의 주파수 특성을 고려하여 철도 소음의 예측 정확도를 향상할 수 있는 예측 모델을 제안하였다. 먼저 철도 소음원을 궤도(레일 및 침목), 차륜, 동력, 공력 성분으로 구분하여 각각의 옥타브 밴드 주파수별 음향파워와 속도계수를 정의하고 음향 조도와 궤도/교량 특성을 반영할 수 있는 보정항을 도입하였다. 소음원에서 수음점까지의 전파 특성은 ISO 9613-2를 적용하여 기하학적 확산, 대기 흡음, 지면 효과, 장애물의 회절에 따른 감쇠 및 지향특성을 반영하여 계산하였다. 소음원 음향파워와 지향인자를 추정하기 위하여 전동 소음원 해석 모델 및 수치해석 결과와 통과 소음도 측정값을 이용하였다. 본 철도 소음 예측 모델을 이용하여 여러 철도 차량과 궤도 유형에 따라서 예측한 소음도를 측정값과 비교하여 정확도를 검증하였으며 기존 예측 모델보다 비교적 정확한 예측이 가능하였다. 따라서 본 결과는 철도 환경 소음의 정확한 영향 예측과 효율적인 소음 저감 대책 수립에 활용될 수 있을 것이다. Approximate empirical equations obtained by measuring overall noise levels at different distances have been used to evaluate environmental influence of the railway noise though the accurate prediction of noise levels is important. In this paper, a noise prediction model considering the frequency characteristics of noise sources and propagation was suggested to improve the accuracy of noise prediction. The railway noise source was assorted into track, wheel, traction and aerodynamic components and they were characterized with the source strength and speed coefficient at each octave-band frequency. Correction terms for the acoustic roughness and the track/bridge condition were introduced. The sound attenuation from a source to a receiver was calculated taking account of the geometrical divergence, atmospheric absorption, ground effect, diffraction at obstacles and directivity of source by applying ISO 9613-2. For obtaining the source strength and speed coefficients, the results of rolling noise model, numerical analysis and measurements of pass-by noise were analyzed. We compared the predicted and measured noise levels in various vehicles and tracks, and verified the accuracy of the present model. It is found that the present model gives less error than the conventional one, so that it can be applied to make the accurate prediction of railway noise effect and establish its countermeasures efficiently.

당해세의 문제

노미리 한국세법학회 2023 조세법연구 Vol.29 No.2

The “relevant tax” pertains to a tax that is imposed on the recognition that property ownership inherently bears a burden. In the realm of national taxes, this tax includes inheritance tax, gift tax, and comprehensive real estate holding tax, as specified in Article 35, Paragraph 3 of the Framework Act on National Taxes. In the case of the relevant tax, the principle of “first- seizured-first-collected basis" is not applied when determining the order of tax claims and collateral, and the legal principle of determining the precedence of the statutory date is not applicable. However, the recognition of absolute priority of the relevant tax, even if the collateral property right is established prior to the statutory date of the tax claim, is challenging to deem reasonable in light of the principle of public disclosure of property rights and the security of transactions. On the other hand, as a response to lease deposits fraud cases, an exception to the principle of prioritization of the relevant tax (Article 35, Paragraph 7 of the Framework Act on National Taxes) was recently introduced. According to this provision, the order of repayment between the relevant tax and housing lease deposit claims is adjusted, but this has the effect of reducing the tax revenue of the relevant tax because the relevant tax cannot be transferred to the national treasury. The provision of exceptions to the “relevant tax” priority principle is meaningful in that it protects the lessee, but it does not fit the legal system in that it only adjusts the order of repayment of the relevant tax and the housing lease deposit claim. In addition, the above provision has limitations in the following points. First, in spite of various reasons why the lease deposit claims of the lessee are not recovered during the public sale or auction, all the lessees are judged uniformly. Second, the priority of reimbursement is adjusted only for the relevant tax imposed on housing, excluding commercial buildings. Third, lease deposit bonds can also be called general bonds, but only because they are related to housing, lease deposit bonds and other general bonds are treated differently. Rather than adjusting the order of repayment between housing lease deposit claims and relevant taxes, the law should be amended to reduce the scope of relevant taxes under the basic principle of respecting the principle of public disclosure of property rights, which is the basis of judicial order. According to the Supreme Court ruling on March 18, 1999, 96da23184, the “relevant tax” must satisfy ① the requirements for property tax in academic terms and ② the requirements for predictability. However, inheritance tax and gift tax have a strong character of distribution tax, and it is difficult to predict the tax amount because it is difficult to know what is in the property to be inherited or gifted, which tax bracket it belongs to, and which tax rate will be applied accordingly. Comprehensive real estate holding tax has a strong character as a policy tax system, so it is difficult to see it as a property tax in academic terms, and it is very difficult to predict the tax amount accordingly because the fair market value ratio, tax base and tax rate change depending on the policy, or the publicly notified prices change every year independently of the policy. Therefore, it is reasonable to exclude inheritance tax, gift tax, and comprehensive real estate holding tax from the scope of the relevant taxes. Even if comprehensive real estate holding tax is not discussed separately, in the case of inheritance tax and gift tax, if it is difficult to exclude from the relevant tax for tax revenue purposes, at least the case of presumed gift or deeming gift should be excluded in Article 35 Paragraph 3 of the Framework Act on National Taxes. Reducing the scope of the national tax corresponding to the relevant tax is expected to solve a significant ... 당해세는 “재산을 소유하고 있는 것 자체에 담세력을 인정하여 부과되는 조세”를 말하며, 국세에서는 상속세, 증여세, 종부세가 당해세에 해당한다(국세기본법 제35조 제3 항). 당해세의 경우에는 조세채권 간의 순서, 담보물권과 조세채권 간의 순서를 정할 때적용하는 압류선착주의, 법정기일의 선후를 따지는 법리가 적용되지 않는다. 그런데 담보물권의 설정시기가 조세채권의 법정기일보다 앞섬에도 불구하고 당해세의 절대적 우선권을 인정하는 것은 물권공시의 원칙과 거래의 안전을 고려했을 때 타당하다고 보기어렵다. 한편, 전세사기 사건의 대책으로 당해세 우선 원칙의 예외 규정(국세기본법 제35조 제7항)이 신설되었다. 외관상 국세기본법 제35조 제7항은 당해세와 주택 임대차보증금채권 간의 변제순위를 조정한 것이지만, 이는 당해세분을 국고로 가지고 오지 못하게 된것이므로 당해세분의 세수가 감소되는 효과가 있다. 당해세 우선 원칙의 예외 규정은 주택 임차인을 보호한다는 점에서는 의미가 있지만, 주택 임대차보증금채권과 당해세의변제순위만 조정한다는 점에서 법체계에 맞지 않는다. 또한, 당해세 우선 원칙의 예외규정은 다음과 같은 한계가 있다. 첫째, 공․경매 시 주택 임차인의 임대차보증금채권이회수되지 않는 이유가 다양함에도 불구하고 모든 주택 임차인을 일률적으로 판단한다. 둘째, 상가는 제외하고 주택에 부과되는 당해세에 한해서만 변제순위를 조정한다. 셋째, 임대차보증금채권도 일반 채권이라고 할 수 있는데, 단지 주거와 관련이 있다는 이유로임대차보증금채권과 다른 일반 채권을 달리 취급한다. 주택 임대차보증금채권과 당해세 간 변제순위를 조정할 것이 아니라, 사법질서의 근간이 되는 물권공시원칙 존중이라는 기본 원칙하에서 당해세의 범위를 축소하는 방향으로 법을 개정해야 한다. 대법원 1999. 3. 18. 선고 96다23184 전원합의체 판결에 의하면, 당해세는 ① 강학상 재산세 요건, ② 예측가능성 요건을 갖추어야 한다. 그런데, 상속세및 증여세는 유통세의 성격이 강하고, 상속․증여받을 재산에 무엇이 있는지, 어떤 과세구간에 속하고 그에 따라 어떤 세율을 적용받게 될지 알기 어려우므로 세액을 예측하기가 어렵다. 종부세는 정책세제로서의 성격이 강하기 때문에 강학상 재산세라고 보기 어렵고, 정책에 따라 공정시장가액비율, 과세표준과 세율이 변경되거나 정책과 별개로 매년 공시가격이 변경되기 때문에 그에 따른 세액을 예측하기가 매우 어렵다. 그러므로 상속세, 증여세, 종부세는 당해세의 범위에서 제외하는 것이 타당하다. 종부세는 별론으로 하더라도 상속세, 증여세의 경우 세수 목적상 당해세에서 제외하는 것이어렵다면, 적어도 증여의제, 증여추정의 경우는 제외한다는 내용을 국세기본법 제35조제3항에 명시하여야 한다. 당해세로서 국세의 범위를 축소하면 당해세 우선 원칙의 예외규정 신설의 발단이 된 임차인의 주택 임대차보증금 회수 문제도 상당 부분 해소될 것으로 예상된다.

Prediction of Physicochemical Properties of Organic Molecules Using Semi-Empirical Methods

김찬경,조수경,김창곤,Mi-Ri Kim,이해황 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.4

Prediction of physicochemical properties of organic molecules is an important process in chemistry and chemical engineering. The MSEP approach developed in our lab calculates the molecular surface electrostatic potential (ESP) on van der Waals (vdW) surfaces of molecules. This approach includes geometry optimization and frequency calculation using hybrid density functional theory, B3LYP, at the 6-31G(d) basis set to find minima on the potential energy surface, and is known to give satisfactory QSPR results for various properties of organic molecules. However, this MSEP method is not applicable to screen large database because geometry optimization and frequency calculation require considerable computing time. To develop a fast but yet reliable approach, we have re-examined our previous work on organic molecules using two semi-empirical methods, AM1 and PM3. This new approach can be an efficient protocol in designing new molecules with improved properties.

Prediction of Physicochemical Properties of Organic Molecules Using Semi-Empirical Methods

Kim, Chan Kyung,Cho, Soo Gyeong,Kim, Chang Kon,Kim, Mi-Ri,Lee, Hai Whang Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.4

Prediction of physicochemical properties of organic molecules is an important process in chemistry and chemical engineering. The MSEP approach developed in our lab calculates the molecular surface electrostatic potential (ESP) on van der Waals (vdW) surfaces of molecules. This approach includes geometry optimization and frequency calculation using hybrid density functional theory, B3LYP, at the 6-31G(d) basis set to find minima on the potential energy surface, and is known to give satisfactory QSPR results for various properties of organic molecules. However, this MSEP method is not applicable to screen large database because geometry optimization and frequency calculation require considerable computing time. To develop a fast but yet reliable approach, we have re-examined our previous work on organic molecules using two semi-empirical methods, AM1 and PM3. This new approach can be an efficient protocol in designing new molecules with improved properties.