A comprehensive approach for managing feasible solutions in production planning by an interacting network of Zero-Suppressed Binary Decision Diagrams

Takahashi, Keita,Onosato, Masahiko,Tanaka, Fumiki Society for Computational Design and Engineering 2015 Journal of computational design and engineering Vol.2 No.2

Product Lifecycle Management (PLM) ranges from design concepts of products to disposal. In this paper, we focus on the production planning phase in PLM, which is related to process planning and production scheduling and so on. In this study, key decisions for the creation of production plans are defined as production-planning attributes. Production-planning attributes correlate complexly in production-planning problems. Traditionally, the production-planning problem splits sub-problems based on experiences, because of the complexity. In addition, the orders in which to solve each sub-problem are determined by priorities between sub-problems. However, such approaches make solution space over-restricted and make it difficult to find a better solution. We have proposed a representation of combinations of alternatives in production-planning attributes by using Zero-Suppressed Binary Decision Diagrams. The ZDD represents only feasible combinations of alternatives that satisfy constraints in the production planning. Moreover, we have developed a solution search method that solves production-planning problems with ZDDs. In this paper, we propose an approach for managing solution candidates by ZDDs' network for addressing larger production-planning problems. The network can be created by linkages of ZDDs that express constraints in individual sub-problems and between sub-problems. The benefit of this approach is that it represents solution space, satisfying whole constraints in the production planning. This case study shows that the validity of the proposed approach.

Dual Purpose Br-Containing Schiff Base Cu(II) Complexes for DSSC Dyes and Polymer Flame Retardants

Takahashi, Keita,Tanaka, Shinnosuke,Yamaguchi, Marin,Tunoda, Yuki,Akitsu, Takashiro,Sugiyama, Mutsumi,Soni, Rakesh Kumar,Moon, Dohyun Korean Chemical Society 2017 대한화학회지 Vol.61 No.3

Dual Purpose Br-Containing Schiff Base Cu(II) Complexes for DSSC Dyes and Polymer Flame Retardants

Keita Takahashi,Shinnosuke Tanaka,Marin Yamaguchi,Yuki Tunoda,Takashiro Akitsu,Mutsumi Sugiyama,Rakesh Kumar Soni,문도현 대한화학회 2017 대한화학회지 Vol.61 No.3

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Effects of the Geometry of Components Attached to the Drain Valve on the Performance of Water Hammer Pumps

Saito, Sumio,Takahashi, Masaaki,Nagata, Yoshimi,Dejima, Keita Korean Society for Fluid machinery 2011 International journal of fluid machinery and syste Vol.4 No.4

Water hammer pumps can effectively use the water hammer phenomenon in long-distance pipeline networks that include pumps and allow fluid transport without drive sources, such as electric motors. The results of experiments that examined the effect of the geometric form of water hammer pumps by considering their major dimensions have been reported. In addition, a paper has also been published analyzing the water hammer phenomenon numerically by using the characteristic curve method for comparison with experimental results. However, these conventional studies have not fully evaluated the pump performance in terms of pump head and flow rate, common measures indicating the performance of pumps. Therefore, as a first stage for the understanding of water hammer pump performance in comparison with the characteristics of typical turbo pumps, the previous paper experimentally examined how the hydrodynamic characteristics were affected by the inner diameter ratio of the drive and lifting pipes, the form of the air chamber, and the angle of the drive pipe. To understand the behavior of the components attached to the valve chamber and the air chamber that affects the performance of water hammer pumps, the previous study also determined the relationship between the water hammer pump performance and temporal changes in valve chamber and air chamber pressures according to the air chamber capacity. For the geometry of components attached to the drain valve, which is another major component of water hammer pumps, this study experimentally examines how the water hammer pump performance is affected by the length of the spring and the angle of the drain pipe.

Effects of the Lift Valve Opening Area on Water Hammer Pump Performance and Flow Behavior in the Valve Chamber

Sumio Saito,Keita Dejima,Masaaki Takahashi,Gaku Hijikata,Takuya Iwamura 한국유체기계학회 2012 International journal of fluid machinery and syste Vol.5 No.3

Water hammer pumps can effectively use the water hammer phenomenon for water pumping. They are capable of providing an effective fluid transport method in regions without a well-developed social infrastructure. The results of experiments examining the effect of the geometric form of water hammer pumps by considering their major dimensions have been reported. However, these conventional studies have not fully evaluated pump performance in terms of pump head and flow rate, common measures of pump performance. The authors have focused on the effects on the pump performance of various geometric form factors in water hammer pumps. The previous study examined how the hydrodynamic characteristics was affected by the inner diameter ratio of the drive and lift pipes and the angle of the drive pipe, basic form factors of water hammer pumps. The previous papers also showed that the behavior of water hammer pump operation could be divided into four characteristic phases. The behavior of temporal changes in valve chamber and air chamber pressures according to the air volume in the air chamber located downstream of the lift valve was also clarified in connection with changes in water hammer pump performance. In addition, the effects on water hammer pump performance of the length of the spring attached to the drain valve and the drain pipe angle, form factors around the drain valve, were examined experimentally. This study focuses on the form of the lift valve, a major component of water hammer pumps, and examines the effects of the size of the lift valve opening area on water hammer pump performance. It also clarifies the behavior of flow in the valve chamber during water hammer pump operation.

Effects of the Lift Valve Opening Area on Water Hammer Pump Performance and Flow Behavior in the Valve Chamber

Saito, Sumio,Dejima, Keita,Takahashi, Masaaki,Hijikata, Gaku,Iwamura, Takuya Korean Society for Fluid machinery 2012 International journal of fluid machinery and syste Vol.5 No.3

Water hammer pumps can effectively use the water hammer phenomenon for water pumping. They are capable of providing an effective fluid transport method in regions without a well-developed social infrastructure. The results of experiments examining the effect of the geometric form of water hammer pumps by considering their major dimensions have been reported. However, these conventional studies have not fully evaluated pump performance in terms of pump head and flow rate, common measures of pump performance. The authors have focused on the effects on the pump performance of various geometric form factors in water hammer pumps. The previous study examined how the hydrodynamic characteristics was affected by the inner diameter ratio of the drive and lift pipes and the angle of the drive pipe, basic form factors of water hammer pumps. The previous papers also showed that the behavior of water hammer pump operation could be divided into four characteristic phases. The behavior of temporal changes in valve chamber and air chamber pressures according to the air volume in the air chamber located downstream of the lift valve was also clarified in connection with changes in water hammer pump performance. In addition, the effects on water hammer pump performance of the length of the spring attached to the drain valve and the drain pipe angle, form factors around the drain valve, were examined experimentally. This study focuses on the form of the lift valve, a major component of water hammer pumps, and examines the effects of the size of the lift valve opening area on water hammer pump performance. It also clarifies the behavior of flow in the valve chamber during water hammer pump operation.

Conformations of Ring Polystyrenes in Semidilute Solutions and in Linear Polymer Matrices Studied by SANS

Iwamoto, Takuro,Doi, Yuya,Kinoshita, Keita,Takano, Atsushi,Takahashi, Yoshiaki,Kim, Eunhye,Kim, Tae-Hwan,Takata, Shin-ichi,Nagao, Michihiro,Matsushita, Yushu American Chemical Society 2018 Macromolecules Vol.51 No.17

<P>Conformations of highly purified ring polystyrene, R-70, with the molar mass of 70 kg/mol, in a good solvent and in linear polymer homologue matrices were examined by small-angle neutron scattering (SANS) measurements. The radii of gyration <I>R</I><SUB>g</SUB> of R-70 were estimated by the Guinier’s approximation from the SANS profiles obtained, and the polymer volume fraction Φ dependence of <I>R</I><SUB>g</SUB><SUP>2</SUP> was discussed. In deuterated toluene as a good solvent, R-70 exhibits the <I>R</I><SUB>g</SUB><SUP>2</SUP> ∼ Φ<SUP>-0.29±0.01</SUP> dependence at high Φ above the overlap volume fraction, Φ<SUB>0</SUB>* (i.e., 1 < Φ/Φ<SUB>0</SUB>* < 20). This exponent −0.29 shows stronger Φ dependence than that for semidilute solutions of linear polymers, −0.25, predicted from the scaling theory, suggesting that the ring expands more sensitively than linear chains when Φ decreases in semidilute regime. In contrast, the Φ dependence of <I>R</I><SUB>g</SUB><SUP>2</SUP> of R-70 is evidently weaker than that of the recent simulation for ring polymer solutions (<I>R</I><SUB>g</SUB><SUP>2</SUP> ∼ Φ<SUP>−0.59</SUP>) by Reigh et al. This difference is thought to originate from the difference in the ring chain length; i.e., the simulation treated much longer rings than the ring adopted in this study. Therefore, it is expected that the exponent −0.29 for the ring polymer solutions obtained in this study is not a limiting value but is a transit one toward higher Φ/Φ<SUB>0</SUB>* region. The size of R-70 is also increased when the ring was diluted with linear polystyrenes. However, the degree of expansion of the rings in linear polymer matrices is considerably lower than that in toluene solutions. Moreover, the molar masses of the linear chains added hardly effect the expansion behavior of the rings. In fact, the dimension of rings gets closer to that of the Gaussian rings as a larger amount of linear chains is added.</P> [FIG OMISSION]</BR>

Mucus Plugs and Small Airway Dysfunction in Asthma, COPD, and Asthma-COPD Overlap

Tamura Kanami,Shirai Toshihiro,Hirai Keita,Nakayasu Hiromasa,Takahashi Shingo,Kishimoto Yutaro,Akamatsu Taisuke,Asada Kazuhiro,Kato Satoshi 대한천식알레르기학회 2022 Allergy, Asthma & Immunology Research Vol.14 No.2

Purpose: There are reports concerning mucus plugs detected on high-resolution computed tomography images and airflow obstruction in asthma and chronic obstructive pulmonary disease (COPD). However, little is known about the associations between mucus plugs and small airway dysfunction (SAD). We evaluated the relationship between mucus plugs and pulmonary function in patients with asthma, COPD, and asthma-COPD overlap (ACO), and investigated the relevance to SAD and type 2 inflammation in a retrospective study. Methods: Subjects included 49 asthmatic, 40 ACO, and 41 COPD patients. ACO was diagnosed based on the Japanese Respiratory Society ACO guidelines. Clinical and laboratory parameters, including blood eosinophil count, serum total IgE levels, fractional exhaled nitric oxide (FeNO), spirometry, and forced oscillation technique (FOT), were compared between patients with and without mucus plugs. Results: Mucus plugs were found in 29 (59%) asthmatic, 25 (65%) ACO, 17 (41%) COPD patients. Patients with mucus plugs had reduced spirometry and larger FOT parameters, especially in COPD patients. Mucus scores correlated positively with IgE in ACO and FeNO in asthmatic patients, but not in COPD patients. Multivariate logistic regression analysis revealed that SAD parameters, including forced vital capacity and resonant frequency, a respiratory reactance parameter, were significantly associated with the presence of mucus plugs in the whole studied population. Conclusions: SAD, rather than large airway dysfunction, was associated with mucus plugs in asthma, ACO, and COPD patients.