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This paper presents the use of a mathematical model in updating a decision maker's belief before selecting a product/system concept and demonstrates a procedure to calculate the maximum monetary value of such a model in terms of the expected value of information. Acquiring information about uncertainty and updating belief according to the new information is an important step in concept selection. However, obtaining additional information can be considered beneficial only if the acquisition cost is less than the benefit. In this paper, a mathematical model is used as an information source that predicts outcomes of an uncertainty. The prediction, however, is imperfect information because the model is constructed based on simplifying assumptions. Thus, the expected value of imperfect information needs to be calculated in order to evaluate the tradeoff between the accuracy and the cost of model prediction (information). The construction and analysis of a mathematical model, the calculation of the expected value of information (model prediction) and updating the belief based on the model prediction are illustrated using a concept selection for a public project. [DOI: 10.1115/1.4001974] Keywords: concept selection, updating belief mathematical model, expected value of information

This paper proposes a game-theoretic model that provides insights into conditions when two engineers collaborate on a design project which has both team and individual components. Collaboration of engineers with diverse technical backgrounds, such as those found in cross-functional teams, has been addressed as a key for successful product development. Similarly, the benefit of a team-based-project class is increasingly emphasized in curriculum development. In a single product design, a team project (in which two engineers work together) may be the design of a product base, and an individual project (in which engineers work individually) may be the design of chunks or modules assembled to the base. In a product family design, a team project may be the design of a product platform and an individual project may be the design of modules assembled to the platform that creates product variants. The proposed model assumes that the engineers receive the same evaluation on their team project (whether they actually contribute to the project or not), and independent evaluations on their individual projects. The proposed model identifies conditions that lead to collaboration of two engineers in the team project, which maximizes product performance. The insights obtained from the model and possible implications in design project and curriculum development are discussed. [DOI: 10.1115/1.4001205] Keywords: collaboration, design project, game theory, prisoner's dilemma

In the conceptual design phase, engineers may need to perceptually screen and prioritize feasible design concepts by their potential to fulfill both customer and financial requirements. This paper presents a system design methodology that integrates perception-based concept evaluation and target costing of complex and large-scale systems. The methodology decomposes a system into modules and evaluates each module concept with its target requirements and cost. This method proposes the decomposition of quality function deployment matrices simultaneously for both requirements and structure in order to allocate the worth and target cost of the modules in a system. Developed from module concepts that satisfy their target requirements and cost, this new system should better satisfy both customer and financial requirements. [DOI: 10.1115/1.2336256] Keywords: concept evaluation, target costing, quality function deployment, requirement and structure decomposition, mapping, modularization, worth allocation

Aims: Recording a voiding diary can be bothersome for patients and is sometimes inaccurate and unhygienic. This study aimed to develop and assess the accuracy and convenience of a novel device that automatically records the voiding diary by measuring pre‐ and post‐void body weight. Methods: We used this novel device for seven healthy volunteers and ten hospitalized patients. The examinees got on the device before and after voiding and the device recorded the voiding diary automatically. The examinees also manually recorded a voiding diary by collecting their urine in a cup and measuring its volume and weight. We examined the correlation between the traditional and the automated voiding diary to confirm the accuracy of voiding measurements using this device. Additionally, we investigated which measurement method was preferred by the participants. Results: In the healthy volunteers group, there was a strong correlation between the voided urine weight recorded by the device and voided urine weight measured manually by the examinee (R2 = 0.9935). In the patients group, there was a strong (R2 = 0.9117) but lower correlation than that of the volunteers group, with an error of ±25 g 62% of the time, and ±50 g 82% of the time, respectively. All of the healthy volunteers and seven of the ten patients preferred using the automated voiding diary. Conclusions: This novel device recorded a reasonably accurate voiding diary for everyday clinical practice. [ABSTRACT FROM AUTHOR]

Introduction: To investigate possible pre-treatment factors related to the therapeutic effect of tadalafil on bladder outlet obstruction (BOO).Materials and Methods: Eighty untreated outpatients with lower urinary tract symptoms (LUTS) due to BOO received 5 mg tadalafil daily for 12 months. Subjective symptoms and objective findings were evaluated before and 12 months after treatment. At 12 months, the patients were divided into two groups according to an improvement grade in BOO index (BOOI). Patient characteristics including age, serum total testosterone level (TT), PSA, and prostate volume, and subjective and objective parameters on LUTS were set as candidates of pre-treatment factors, and the parameters that influenced the improvement of BOO were statistically analysed.Results: A total of 69 patients with mean age of 69.8 years and mean prostate volume of 48.8 mL were included. Subjective symptoms and BOOI were significantly ameliorated after 12 months. In terms of an improvement of BOOI, 30 patients (43.5%) showed insignificant improvement in BOO, whereas 39 patients (56.5%) exhibited excellent improvement. Comparison of pre-treatment factors between the groups showed that TT was the only independent predictor related to the improvement in BOO. The improvement of BOO was significantly better in patients with higher TT.Conclusions: Pre-treatment TT was considered to be a useful predictor of therapeutic effects of tadalafil for BOO. [ABSTRACT FROM AUTHOR]

Objective: To investigate the clinical characteristics and useful signs to differentiate detrusor underactivity from bladder outlet obstruction in men with non‐neurogenic lower urinary tract symptoms. Methods: A total of 638 treatment‐naive men with non‐neurogenic lower urinary tract symptoms who underwent subjective and objective evaluations were reviewed retrospectively. We divided the patients into detrusor underactivity and bladder outlet obstruction groups based on urodynamic findings, and compared parameters obtained from questionnaires and non‐invasive tests. Detrusor underactivity was defined as bladder contractility index ≤100 and bladder outlet obstruction index ≤40, whereas bladder outlet obstruction was defined as bladder contractility index >100 and bladder outlet obstruction index >40. Results: Of 638 patients, 145 (22.7%) had detrusor underactivity and 273 (42.8%) had bladder outlet obstruction. Total international prostate symptom score and international prostate symptom score‐voiding subscore were significantly higher in the detrusor underactivity group. There were significant differences in prostate volume, intravesical prostatic protrusion, and all uroflowmetry parameters between the two groups. In multivariate logistic regression analysis, lower intravesical prostatic protrusion (cut‐off value 8.2 mm), lower bladder voiding efficiency (cut‐off value 70%), and the presence of sawtooth and interrupted waveform on uroflowmetry were significant predictive factors for detrusor underactivity. In particular, the incidence of sawtooth and interrupted waveform was significantly higher in the detrusor underactivity group (80%) than in the bladder outlet obstruction group (12.8%), which showed both high sensitivity (80%) and specificity (87.2%) in differentiating detrusor underactivity from bladder outlet obstruction. Conclusions: Sawtooth and interrupted waveform on uroflowmetry can be a useful predictive factor for detrusor underactivity. In addition, lower intravesical prostatic protrusion and bladder voiding efficiency can be of supplementary use. [ABSTRACT FROM AUTHOR]