• Title/Summary/Keyword: ADI Technique

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Numerical Simulation of Chemically Reacting Laminar and Thrbulent Flowfields Using Preconditioning Scheme (예조건화 기법을 이용한 층류 및 난류 화학반응 유동장 해석)

  • Kim Gyo-Soon;Choi Yun-Ho;Rhee Byung-Ohk;Song Bong-Ha
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.30 no.4 s.247
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    • pp.320-327
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    • 2006
  • The computations of chemically reacting laminar and turbulent flows are performed using the preconditioned Navier-Stokes solver coupled with turbulent transport and multi-species equations. A low-Reynolds number $k-\varepsilon$ turbulence model proposed by Chien is used. The presence of the turbulent kinetic energy tenn in the momentum equation can materially affect the overall stability of the fluids-turbulence system. Because of this coupling effect, a fully coupled formulation is desirable and this approach is taken in the present study. Choi and Merkle's preconditioning technique is used to overcome the convergence difficulties occurred at low speed flows. The numerical scheme used for the present study is based on the implicit upwind ADI algorithm and is validated through the comparisons of computational and experimental results for laminar methane-air diffusion flame and $ H_2/O_2$ reacting turbulent shear flow. Preconditioning formulation shows better convergence characteristics than that of non-preconditioned system by approximately five times as much.

Financial Management Information System, Human Resource Competency and Financial Statement Accountability: A Case Study in Indonesia

  • SAPUTRA, Komang Adi Kurniawan;SUBROTO, Bambang;RAHMAN, Aulia Fuad;SARASWATI, Erwin
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.5
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    • pp.277-285
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    • 2021
  • This study aims to examine the effect of variables of financial management information systems, organizational culture, and human resource competence on the accountability of village government financial reporting. The sample was 65 villages in the two districts using a simple random sampling technique. To analyze the data of this research, multiple regression analysis was conducted. The results showed that organizational culture as a differentiator in the two districts, namely financial management information systems, organizational culture, and human resource competence has a significant positive effect on accountability in preparing village government financial reports in Tabanan Regency. Meanwhile, organizational culture does not have a significant influence in Badung Regency, this is because each village government has a different work culture. In the Tabanan regency, we use local culture as the basis for organizational culture, while in the Badung regency it can be examined between organizational culture and it is carried out differently, which indicates that no one organizational culture type is superior to other types. This means that all types can move in line with and hand-in-hand based on how and when organizational goals are to be realized.

Influence of Human Resources, Financial Attitudes, and Coordination on Cooperative Financial Management

  • ATMADJA, Anantawikrama Tungga;SAPUTRA, Komang Adi Kurniawan;TAMA, Gede Mandirta;PARANOAN, Selmita
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.2
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    • pp.563-570
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    • 2021
  • The importance of cooperative financial management is expected to be able to encourage the needs of the community especially towards the supervision of cooperatives and human resources. The study was conducted aiming to determine the effect of human resources, financial attitudes, and coordination on cooperative financial management. Research with quantitative methods. The study was conducted with multiple regression methods, while the sampling technique was based on a random sample of samples with the data collection method using a survey method in the form of a questionnaire that was measured with a Likert scale. The method of determining the research sample is done by calculating the Slovin formula, determining the research sample of 166 cooperatives in Buleleng Regency, Bali Province. The results of the research prove that partial human resources have a significant positive effect on cooperative financial management, financial attitude variables have a significant positive effect on cooperative financial management and coordination variables have a significant positive effect on cooperative financial management. The results of this study can be stated that the better the financial management of cooperatives, better will be the impact on cooperative growth so that the need for more competent resources in cooperative management.

A Study on Change of Sea Water Quality due to the Development Plan of Ilgwang Harbour (일광항의 항만개발에 따른 수질변화에 관한 연구)

  • 이중우;국승기
    • Journal of Korean Port Research
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    • v.12 no.2
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    • pp.303-312
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    • 1998
  • It is necessary to quantitatively asses the influence of tidal currents to analysis the coastal current patterns before or after constructing offshore structures like as breakwaters. This assesment can be made through the use of simulation models designed to reproduce the water movements of the area. And it is very important to predict a phenomenon of pollutant dispersion in the area. In this study, in order to predict the changes of sea water quality for the port development plan, Ilgwang harbour, located at the east coast of Pusan, the numerical computations were carried out. The flow patterns were investigated before and after the development of the harbour bay and coastal area connected on it. The computational models are an extension of earlier work on the flow which used the ADI Method (Alternating Direction Implicit Method) in appling to Osaka Bay by KANEKO et al. The transport of pollutant constituents depends upon the currental characteristics of the water-transporting medium. In the currental flow model, water velocities and water levels are computed throughout the regions of it. These value are then used in the mass-balance equation to obtain the pollutant-constituent transport. As a result of this research, the present water quality of Ilgwang harbour and the coastal areas connected on it was proved out some good condition. The changes of sea water quality due to the port development plan of the Ilgwang habour bay and the coastal area were not large compared with the present condition, but it will be likely able to get worse by increasing the semi-enclosed areas in the harbour bay. In order to improve the water quality of the area after development, the method to activate tidal exchange in the area can be needed, as a mitigation technique.

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Automatic False-Alarm Labeling for Sensor Data

  • Adi, Taufik Nur;Bae, Hyerim;Wahid, Nur Ahmad
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.2
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    • pp.139-147
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    • 2019
  • A false alarm, which is an incorrect report of an emergency, could trigger an unnecessary action. The predictive maintenance framework developed in our previous work has a feature whereby a machine alarm is triggered based on sensor data evaluation. The sensor data evaluator performs three essential evaluation steps. First, it evaluates each sensor data value based on its threshold (lower and upper bound) and labels the data value as "alarm" when the threshold is exceeded. Second, it calculates the duration of the occurrence of the alarm. Finally, in the third step, a domain expert is required to assess the results from the previous two steps and to determine, thereby, whether the alarm is true or false. There are drawbacks of the current evaluation method. It suffers from a high false-alarm ratio, and moreover, given the vast amount of sensor data to be assessed by the domain expert, the process of evaluation is prolonged and inefficient. In this paper, we propose a method for automatic false-alarm labeling that mimics how the domain expert determines false alarms. The domain expert determines false alarms by evaluating two critical factors, specifically the duration of alarm occurrence and identification of anomalies before or while the alarm occurs. In our proposed method, Hierarchical Temporal Memory (HTM) is utilized to detect anomalies. It is an unsupervised approach that is suitable to our main data characteristic, which is the lack of an example of the normal form of sensor data. The result shows that the technique is effective for automatic labeling of false alarms in sensor data.

The pathogenicity of Streptococcus parauberis isolated from cultured olive flounder Paralichthys olivaceus (양식 넙치, Paralichthys olivaceus에서 분리한 연쇄구균증 원인균, Streptococcus parauberis의 병원성)

  • Choi, Hee-Jung;Cho, Mi-Young;Lee, Jae-Il;Kwon, Mun-Gyeong;Choi, Dong-Lim;Kim, Jin-Woo;Han, Myoung-Chul;Lee, Deok-Chan
    • Journal of fish pathology
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    • v.22 no.3
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    • pp.263-273
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    • 2009
  • There is an increasing number of reports describing Streptococcus parauberis as an important pathogen of cultured olive flounder Paralichthys olivaceus and starry flounder Platichthys stellatus in Korea. We tried to determine the effects of water temperature (14${^{\circ}C}$ and 21${^{\circ}C}$) on the pathogenicity in Streptococcal disease caused by S. parauberis. We have challenged 180 olive flounder by i.p injection to $2.0{\times}10^{7}$ live cells/fish. Mortality was monitored for 21 days post challenge. And histopathological characterizations as infection degree, tissue degeneration and/or bacterial distribution were investigated with H&E stain and in situ hybridization technique. Fifty percent and 16.7% of mortality occurred within 21 days at 21${^{\circ}C}$ and 14${^{\circ}C}$ water temperature, respectively. In most cases, the typical symptoms of olive flounder infected with S. parauberis were darkness of the skin, lethargy, mild abdominal distension cause by ascites, splenomegaly, congested liver and internal organs paleness. The pericardial sac contained large amounts of cloudy fluid. Numerous whitish nodules, which were variable in size and often confluent, were randomly scattered throughout the myocardium. Especially, pericarditis and/or myocarditis was observed in all tested fishes after death. Positive in reaction with S. parauberis were found in all tissues in situ hybridization analysis. The relative numbers of S. parauberis in heart were much more than in liver, spleen, kidney and stomach. We evaluated that S. parauberis strain causes serious damage in the pericardium, shortness of breath and the blood disorder. Therefore, pericarditis and myocarditis caused by S. parauberis were closely related to mortality of olive flounder.