Effects of Clogging on Settlement Predictions of Ground Improved with Stone Columns

Pei Tai,Chao Zhou 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.9

Clogging of stone column (i.e., the mixture of column material and surrounding soil) is widely reported as well as its hindrance effect on the consolidation rate of soft ground improved with stone columns, however, its influence may be more complicated in settlement estimations. In this study, a modified consolidation model is proposed for making predictions of settlement with consideration of clogging. Its influence on permeability and compressibility is included while both radial and vertical flow in stone column are taken into account. Parametric studies reveal that the consolidation rate will be largely impeded if the permeability of clogged column drops below that of surrounding clay. The short-term settlement is lower mainly because of the reduction of permeability. On the contrary, the long-term settlement becomes larger due to an increase in compressibility. This finding implies that the final settlement may be underestimated if the clogging effects are not incorporated even when early field observations are available, as supported by a design example.

Interactive Motion Planning for Autonomous Robotic Photo Taking

Pei-Chun Lu,Kai-Tai Song 제어로봇시스템학회 2021 제어로봇시스템학회 국제학술대회 논문집 Vol.2021 No.10

In this paper, a motion planning method is proposed for an autonomous photo-taking robot. The developed human-robot interactive motion planning and control system is based on face recognition and facial pose estimation of a target person. The target person’s location is estimated after combined with robot self-localization result. Then the goal position and orientation of the robot are determined for autonomous photo-taking of the specific person. An APP for mobile phones has been integrated to select the target person and transmit the command to the robot for photo taking. After receiving the command, the robot autonomously navigates to the goal location and shoots pictures of the target person. Experimental results show that the experimental mobile robot can recognize the specific person, regardless the person is stand alone or in a crowd. The robot completed two types of picture-taking tasks by using the proposed method.

Investigation of fire resistance of cement pastes reinforced by graphene nanoribbons

Li, Pei-Qi(리패기),Liu, Jun-Xing(유준성),Piao, Tai-Yan(퍄오 타이옌),Bae, Sung-Chul(배성철) 대한건축학회 2023 대한건축학회 학술발표대회 논문집 Vol.43 No.1

Mechanism of Packing Rigidity Gain in Sand Aging: From the Perspective of Structural Order Evolution

Chengjun Liu,Pei Tai,Zhaofeng Li,Wenbiao Hu 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.6

Rigidity gain can be observed in sand aging but is usually accompanied by minute densification.This phenomenon is inconsistent with the conventional diagram of rigidity/jamming transition for granules and therefore too enigmatic to be utilized in the field by engineers. Therefore, this study aims to reveal the mechanism of rigidity gain and reconcile the inconsistency in sand aging. The aging processes of two sand packings with the same mono-sized spheres but different initial densities were reproduced via discrete element method simulations. In the simulations, sudden increases in the solid fraction destroyed the similarity between the evolution processes of rigidity gain and densification, confirming the inadequacy of explaining this gain considering densification alone. The bond-orientational order remained almost unchanged, while the contact-force order generally increased over time with distinct drops, similar to the change in rigidity gain. This evolution pattern is attributed to the laws of thermodynamics, which require the Gibbs energy of the sand packing to decrease over time, and contact-force order reduction assists with this decrease. Simultaneously, this reduces the nonaffinity under shear and rigidity demolition, consequently dominating the rigidity gain mechanism in sand aging. Based on these findings, the conventional diagram of rigidity transition was modified to jointly consider the effects of the solid fraction and structural orders. The proposed diagram can depict how the sand packing rigidity is enhanced over time and can better guide the consideration of the sand aging effect in the field.

Effect of mixture ratio and accelerator on the mechanical strength of cement mortar for binder jet 3D printing

Liu, Jun-Xing(유준성),Li, Pei-Qi(리패기),Piao, Tai-Yan(퍄오 타이옌),Bae, Sung-Chul(배성철) 대한건축학회 2023 대한건축학회 학술발표대회 논문집 Vol.43 No.1

Clinical and Histologic Features of Patients with Biopsy-Proven Metabolic Dysfunction-Associated Fatty Liver Disease

( Shang-chin Huang ),( Hau-jyun Su ),( Jia-horng Kao ),( Tai-chung Tseng ),( Hung-chih Yang ),( Tung-hung Su ),( Pei-jer Chen ),( Chun-jen Liu ) 대한간학회 2021 Gut and Liver Vol.15 No.3

Background/Aims: Fatty liver disease is defined as a cluster of diseases with heterogeneous etiologies, and its definition continues to evolve. The novel conceptional criteria for metabolic dysfunction-associated fatty liver disease (MAFLD) were proposed in 2020 to avoid the exclusion of a certain subpopulation, but their evaluations have been limited. We aimed to examine and compare the clinical as well as histologic features of MAFLD versus nonalcoholic fatty liver disease (NAFLD) in patients with biopsy-proven hepatic steatosis. Methods: From January 2009 to December 2019, 175 patients with histology-proven hepatic steatosis and 10 with cryptogenic cirrhosis who were treated at National Taiwan University Hospital, Taipei, Taiwan, were enrolled. Patients were classified into different groups according to the diagnostic criteria of MAFLD and NAFLD. The clinical and histologic features were then analyzed and compared. Results: In total, 76 patients (41.1%) were diagnosed with both MAFLD and NAFLD, 81 patients (43.8%) were diagnosed with MAFLD alone, nine patients (4.9%) were diagnosed with NAFLD alone, and 19 patients (10.3%) were diagnosed with neither. Those with MAFLD alone exhibited a higher degree of disease severity regarding histology and laboratory data than those with NAFLD alone. Advanced fibrosis was associated with the presences of hepatitis B virus infection and metabolic diseases. Conclusions: The novel diagnostic criteria for MAFLD include an additional 38.9% of patients with hepatic steatosis and can better help identify those with a high degree of disease severity for early intervention than can the previous NAFLD criteria. (Gut Liver 2021;15:451-458)

Impact of Peri-Operative Anemia and Blood Transfusions in Patients with Gastric Cancer Receiving Gastrectomy

Chang, Chih-Chun,Sun, Jen-Tang,Chen, Jing-Yuan,Chen, Yi-Ting,Li, Pei-Yu,Lee, Tai-Chen,Su, Ming-Jang,Wu, Jiann-Ming,Yen, Tzung-Hai,Chu, Fang-Yeh Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.3

Background: Potential disadvantages of blood transfusion during curative gastrectomy for gastric cancer have been reported, and the role of peri-operative transfusions remains to be ascertained. Thus, the aim of our study was to survey its impact in patients with gastric cancer undergoinging gastrectomy. Materials and Methods: Clinical data of patients receiving curative gastrectomy at Far Eastern Memorial Hospital were obtained. Findings for pre-operative anemia states, pre-, peri- and post-operative transfusion of red blood cell (RBC) products as well as post-operative complication events were collected for univariate analysis. Results: A total of 116 patients with gastric cancer received gastrectomy at Far Eastern Memorial Hospital from 2011 to 2014. Both pre-operative and intra- and post-operative transfusion of RBC products were markedly associated with post-operative infectious events (OR: 3.70, 95% CI: 1.43-9.58, P=0.002; OR: 8.20, 95% CI: 3.11-22.62, P<0.001, respectively). In addition, peri- and post-operative RBC transfusion was significantly associated with prolonged hospital stay from admission to discharge (OR: 8.66, 95% CI: 1.73-83.00, P=0.002) and post-operative acute renal failure (OR: 19.69, 95% CI: 2.66-854.56, P<0.001). Also, the overall survival was seemingly decreased by peri-operative RBC transfusion in our gastric cancer cases (P=0.078). Conclusions: Our survey indicated that peri-operative RBC transfusion could increase the risk of infectious events and acute renal failure post curative gastrectomy as well as worsen the overall survival in gastric cancer cases. Hence, unnecessary blood transfusion before, during and after curative gastrectomy should be avoided in patients with gastric cancer.