The Use of a Multiple Risk Level Model to Tackle the Duration of Risk for Construction Activity

Hsien-Kuan Chang,Wen-der Yu,Shao-Tsai Cheng,Tao-Ming Cheng 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.6

The project evaluation and review technique (PERT) is the most well-known method to handle the risk due to uncertain activity durations, previous studies show that the β-distribution-based PERT estimation tends to be over-optimistic and it offers no control of the project in terms of risk duration. This study proposes a multiple risk-level (MRL) model that uses a site spatial constraint, environmental effects and the “5 Ms” of construction management to tackle the duration of risk during a construction project. A Risk-based Critical Path Scheduling Method (R-CPSM) that uses MRL is developed to calculate the duration of the project. A case study using a project selected from a previous study is used to compare the four estimation methods: two traditional PERT methods (3.2σs and 6σs), a Monte Carlo Simulation and the proposed MRL model. The results show that, compared with traditional approaches to estimate durations of uncertain activity, the proposed R-CPSM method is more systematic that can be combined with a cost estimation process and offers a rectification mechanism that dynamically monitors and adjusts the important factors that affect the risk duration. This method gives a more realistic estimate that is in agreement with the results of previous studies.

Incorporating a continuous suction system as a preventive measure against fistula-related complications in head and neck reconstructive surgery

Hsien Pin Chang,홍종원,이원재,김영석,Yoon Woo Koh,Se-Heon Kim,유대현,노태석 대한성형외과학회 2018 Archives of Plastic Surgery Vol.45 No.5

Background Although previous studies have focused on determining prognostic and causative variables associated with fistula-related complications after head and neck reconstructive surgery, only a few studies have addressed preventive measures. Noting that pooled saliva complicates wound healing and precipitates fistula-related complications, we devised a continuous suction system to remove saliva during early postoperative recovery. Methods A continuous suction system was implemented in 20 patients after head and neck reconstructive surgery between January 2012 and October 2017. This group was compared to a control group of 16 patients at the same institution. The system was placed orally when the lesion was on the anterior side of the retromolar trigone area, and when glossectomy or resection of the mouth floor was performed. When the orohypopharynx and/or larynx were eradicated, the irrigation system was placed in the pharyngeal area. Results The mean follow-up period was 9.2±2.4 months. The Hemovac system was applied for an average of 7.5 days. On average, 6.5 days were needed for the net drain output to fall below 10 mL. Complications were analyzed according to their causes and rates. A fistula occurred in two cases in the suction group. Compared to the control group, a significant difference was noted in the surgical site infection rate (P<0.031). Conclusions Clinical observations showed reduced saliva pooling and a reduction in the infection rate. This resulted in improved wound healing through the application of a continuous suction system.

Development of an easy-to-handle murine model for the characterization of radiation-induced gross and molecular changes in skin

Hsien Pin Chang,조재호,이원재,노현,이동원 대한성형외과학회 2018 Archives of Plastic Surgery Vol.45 No.5

Background Radiation-induced skin injury is a dose-limiting complication of radiotherapy. To investigate this problem and to develop a framework for making decisions on treatment and dose prescription, a murine model of radiation-induced skin injury was developed. Methods The dorsal skin of the mice was isolated, and irradiation was applied at single doses of 15, 30, and 50 Gy. The mice were followed for 12 weeks with serial photography and laser Doppler analysis. Sequential skin biopsy samples were obtained and subjected to a histological analysis, immunostaining against transforming growth factor beta (TGF-β), and Western blotting with Wnt-3 and β-catenin. Increases in the levels of TGF-β, Wnt, and β-catenin were detected after irradiation. Results All tested radiation doses caused progressive dermal thickening and fibrosis. The cause of this process, however, may not be radiation alone, as the natural course of wound healing may elicit a similar response. The latent appearance of molecular and histological markers that induce fibrosis in the 15 Gy group without causing apparent gross skin injuries indicates that 15 Gy is an appropriate dose for characterizing the effects of chronic irradiation alone. Thus, this model best mimics the patterns of injury that occur in human subjects. Conclusions This animal model can be used to elucidate the gross and molecular changes that occur in radiation-induced skin injury and provides an effective platform for studying this adverse effect without complicating the process of wound healing.

Effects of Acupuncture at Pai-Hui on the Deficit of Memory

Chang, Yung-Hsien,Hsieh, Ming-Tsuen,Wu, Chi-Rei 경희대학교 2001 INTERNATIONAL SYMPOSIUM ON EAST-WEST MEDICINE Vol.2001 No.1

Acupuncture has been introduced as one of the complementary therapies in traditional Chinese medicine. In addition to the analgesic effect, acupuncture also has anti-inflammatory, anti-allergic and immunomodulatory effects. Activation of the Bai-Hui by acupuncture was further shown to correct loss of consciousness, as well as to relieve mental abstraction, sluggish speech and hysteria. In this study, we investigated the attenuating effect of Pal-Hui acupuncture on scopolamine (SCOP)-induced or cycloheximide (CXM)-induced impairment of the passive avoidance response in rats. Our preliminary results indicated that acupuncture at Pal-Hui before or immediately after the training trial could significantly attenuate SCOP-induced impairment in rats. The effects were better than those treated before the right-room retention trial. Interestingly, the identical procedure could also significantly attenuate the CXM-induced impairment, but not those treated before the retention trial. The correction effect of acupuncture on CXM-induced impairment was equivalent to that of piracetam treatment. Acupunctures at Pal-Hui 15,30 or 60 min before the training trial could he all effective to attenuate CXM-induced impairment, and its efficacy paralleled acupuncture duration. Furthermore, we demonstrated the mechanism of the attenuating effects of acupuncture at Pal-Hui on CXM-induced memory consolidation deficits by combined with SCOP or p-chloroamphetamine(PCA). The attenuating effects of acupuncture at Pal-Hui was significantly antagonized by PCA but not SCOP. These results suggest acupuncture at Pal-Hui might mainly affect the memory storage process and had preventive and immediate therapeutic effects on the CXM-induced impairment and its efficacy paralleled acupuncture duration. The preventive effect of acupuncture at Pal-Hui on CXM-induced impairment is significantly reduced by serotonergic 5-HT releaser. However, the detailed mechanism of acupuncture on memory function and the differential mechanism of acupuncture on memory function an analgesia must be further investigated.

Incorporating a continuous suction system as a preventive measure against fistula-related complications in head and neck reconstructive surgery

Chang, Hsien Pin,Hong, Jong Won,Lee, Won Jai,Kim, Young Seok,Koh, Yoon Woo,Kim, Se-Heon,Lew, Dae Hyun,Roh, Tae Suk Korean Society of Plastic and Reconstructive Surge 2018 Archives of Plastic Surgery Vol.45 No.5

Background Although previous studies have focused on determining prognostic and causative variables associated with fistula-related complications after head and neck reconstructive surgery, only a few studies have addressed preventive measures. Noting that pooled saliva complicates wound healing and precipitates fistula-related complications, we devised a continuous suction system to remove saliva during early postoperative recovery. Methods A continuous suction system was implemented in 20 patients after head and neck reconstructive surgery between January 2012 and October 2017. This group was compared to a control group of 16 patients at the same institution. The system was placed orally when the lesion was on the anterior side of the retromolar trigone area, and when glossectomy or resection of the mouth floor was performed. When the orohypopharynx and/or larynx were eradicated, the irrigation system was placed in the pharyngeal area. Results The mean follow-up period was $9.2{\pm}2.4$ months. The Hemovac system was applied for an average of 7.5 days. On average, 6.5 days were needed for the net drain output to fall below 10 mL. Complications were analyzed according to their causes and rates. A fistula occurred in two cases in the suction group. Compared to the control group, a significant difference was noted in the surgical site infection rate (P<0.031). Conclusions Clinical observations showed reduced saliva pooling and a reduction in the infection rate. This resulted in improved wound healing through the application of a continuous suction system.

Exendin-4 improves resistance to Listeria monocytogenes infection in diabetic db/db mice

Hsien Yueh Liu,Chih-Yao Chung,Wen-Chin Yang,Chih-Lung Liang,Chi-Young Wang,Chih-Yu Chang,Cicero Lee-Tian Chang 대한수의학회 2012 Journal of Veterinary Science Vol.13 No.3

The incidence of diabetes mellitus is increasing among companion animals. This disease has similar characteristics in both humans and animals. Diabetes is frequently identified as an independent risk factor for infections associated with increased mortality. In the present study, homozygous diabetic (db/db) mice were infected with Listeria (L.) monocytogenes and then treated with the anti-diabetic drug exendin-4, a glucagon-like peptide 1 analogue. In aged db/db mice, decreased CD11b+ macrophage populations with higher lipid content and lower phagocytic activity were observed. Exendin-4 lowered high lipid levels and enhanced phagocytosis in macrophages from db/db mice infected with L. monocytogenes. Exendin-4 also ameliorated obesity and hyperglycemia, and improved ex vivo bacteria clearance by macrophages in the animals. Liver histology examined during L. monocytogenes infection indicated that abscess formation was much milder in exendin-4-treated db/db mice than in the control animals. Moreover, mechanistic studies demonstrated that expression of ATP binding cassette transporter 1, a sterol transporter, was higher in macrophages isolated from the exendin-4-treated db/db mice. Overall, our results suggest that exendin-4 decreases the risk of infection in diabetic animals by modifying the interaction between intracellular lipids and phagocytic macrophages.

Development of an easy-to-handle murine model for the characterization of radiation-induced gross and molecular changes in skin

Chang, Hsien Pin,Cho, Jae Ho,Lee, Won Jai,Roh, Hyun,Lee, Dong Won Korean Society of Plastic and Reconstructive Surge 2018 Archives of Plastic Surgery Vol.45 No.5

Background Radiation-induced skin injury is a dose-limiting complication of radiotherapy. To investigate this problem and to develop a framework for making decisions on treatment and dose prescription, a murine model of radiation-induced skin injury was developed. Methods The dorsal skin of the mice was isolated, and irradiation was applied at single doses of 15, 30, and 50 Gy. The mice were followed for 12 weeks with serial photography and laser Doppler analysis. Sequential skin biopsy samples were obtained and subjected to a histological analysis, immunostaining against transforming growth factor beta (TGF-${\beta}$), and Western blotting with Wnt-3 and ${\beta}$-catenin. Increases in the levels of TGF-${\beta}$, Wnt, and ${\beta}$-catenin were detected after irradiation. Results All tested radiation doses caused progressive dermal thickening and fibrosis. The cause of this process, however, may not be radiation alone, as the natural course of wound healing may elicit a similar response. The latent appearance of molecular and histological markers that induce fibrosis in the 15 Gy group without causing apparent gross skin injuries indicates that 15 Gy is an appropriate dose for characterizing the effects of chronic irradiation alone. Thus, this model best mimics the patterns of injury that occur in human subjects. Conclusions This animal model can be used to elucidate the gross and molecular changes that occur in radiation-induced skin injury and provides an effective platform for studying this adverse effect without complicating the process of wound healing.

A Quantity-Based Method to Predict More Accurate Project Completion Time

Hsien-Kuan Chang,Wen-der Yu,Tao-Ming Cheng 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.10

‘Completion in time’ is a crucial element of project management. Previous studies show that earned value management (EVM), earned schedule method, or earned duration management do not give an accurate project completion time estimation (PCTE) because of theoretical weaknesses. Inaccurate PCTE may provide misleading information, so that the project manager cannot take effective schedule control actions timely, and thus it results in failure of project time management. To improve the above-mentioned problem, this research proposes a quantity-based project duration estimating method (Q-PDEM), which calculates the PCTE using the de facto work quantities and the updated productivity information of activities. The results of two case studies show that the proposed Q-PDEM gives a 7.55% better mean absolute percentage error (MAPE) than the existing methods for predicted project completion duration for Case I, and 24.54% for Case II. It is concluded that the proposed Q-PDEM gives a more accurate estimation of the time for project completion and allows more effective control of the project schedule.

The feasibility of detecting endometrial and ovarian cancer using DNA methylation biomarkers in cervical scrapings

Cheng-Chang Chang,Hui-Chen Wang,Yu-Ping Liao,Yu-Chih Chen,Yu-Chun Weng,Mu-Hsien Yu,Hung-Cheng Lai 대한부인종양학회 2018 Journal of Gynecologic Oncology Vol.29 No.1

Objective: We hypothesized that DNA methylation of development-related genes may occur in endometrial cancer (EC)/ovarian cancer (OC) and may be detected in cervical scrapings. Methods: We tested methylation status by quantitative methylation-specific polymerase chain reaction for 14 genes in DNA pools of endometrial and OC tissues. Tissues of EC/normal endometrium, OC/normal ovary, were verified in training set using cervical scrapings of 10 EC/10 OC patients and 10 controls, and further validated in the testing set using independent cervical scrapings in 30 EC/30 OC patients and 30 controls. We generated cutoff values of methylation index (M-index) from cervical scrapings to distinguish between cancer patients and control. Sensitivity/specificity of DNA methylation biomarkers in detecting EC and OC was calculated. Results: Of 14 genes, 4 (PTGDR, HS3ST2, POU4F3, MAGI2) showed hypermethylation in EC and OC tissues, and were verified in training set. POU4F3 and MAGI2 exhibited hypermethylation in training set were validated in independent cases. The mean M-index of POU4F3 is 78.28 in EC and 20.36 in OC, which are higher than that in controls (6.59; p<0.001 and p=0.100, respectively), and that of MAGI2 is 246.0 in EC and 12.2 in OC, which is significantly higher that than in controls (2.85; p<0.001 and p=0.480, respectively). Sensitivity and specificity of POU4F3/MAGI2 were 83%–90% and 69%–75% for detection of EC, and 61% and 62%–69% for the detection of OC. Conclusion: The findings demonstrate the potential of EC/OC detection through testing for DNA methylation in cervical scrapings.

The Effects of Low Temperatures on Larval Survival of Aedes aegypti andAe. albopictus (Diptera: Culicidae) in Taiwan

Lun-Hsien Chang,Err-Lieh Hsu 한국응용곤충학회 2005 한국응용곤충학회 학술대회논문집 Vol.2005 No.05