202 research outputs found

    Managerial Control inside the Firm

    Get PDF
    This paper proposes an implicit control mechanism of managers inside the firm. We argue that the need to motivate workers may make it beneficial for a self-interested, short-sighted manager to pursue long-run viability of the firm. When the firm is in a stable environment, this implicit control mechanism may not contradict shareholder value maximization. However, when the firm needs restructuring, this mechanism damages firm value. We discuss when external governance is desirable, and when it is not. Our model also offers economic explanations for some related issues in managerial behavior such as restructuring aversion, survival motive, and excessive risk aversion.

    A Study on High Efficiency Wing-Vane Compressor - Part.2: Lubrication Characteristic of The Partial Arc Guide Bearing -

    Get PDF
    Low global warming refrigerants such as HFO (hydro fluoro olefin) -1234yf are attracted as an alternative working fluid in air-conditioning and cooling systems to address global warming. However, it used to require larger compressor size due to the lower fluid density compared with conventional refrigerants such as R410A. Thus, a new wing-vane compressor which has no contraction between the vane and the cylinder is developed to prevent increase in the size without performance degradation. Ă‚ Rotary motion of the vane is supported by the partial arc guide on the upper and lower ends of the vane. Revealing the lubricating properties of the guide was one of the development issues. Ă‚ So we have analyzed the guide bearing performance such as friction coefficient and oil film thickness with fluid dynamics lubrication model of the guide bearing. And we measured the friction coefficient of the guide bearing by experiment. The analysis model was validated by comparing the simulated friction coefficient and that of experiment. In addition, we examined the effect of the shape of the guide bearing on the lubricating properties. The results are as follows: (1)When the load is applied to the center of the guide arc angle, the friction coefficient of the analysis and experiment result is in good agreement. (2)The friction coefficient of the guide bearing can be organized in Stribeck diagram as well as full journal bearing in the fluid lubrication region

    A Study on High Efficiency Wing-vane Compressor - Part.3: Experimental Evaluation of the Prototype -

    Get PDF
    Low global warming refrigerants such as HFO (hydro fluoro olefin) -1234yf are attracted as an alternative working fluid in air-conditioning and cooling systems to address global warming. However, it used to require larger compressor size due to the lower fluid density compared with conventional refrigerants such as R410A. Thus, a new wing-vane compressor which has no contraction between the vane and the cylinder is developed to prevent increase in the size without performance degradation. The structure of the wing-vane compressor is different from the conventional vane compressor. Therefore, a prototype of the wing-vane compressor was operated using R134a refrigerant to simulate HFO-1234yf refrigerant. The results are as follows: (1) The steady operation is observed in the general operating condition. (2) The steady mechanism of vane is clarified by both experiment and simulation. (3) A simple lubrication structure is achieved by supplying the oil to the friction surface through the grooves with the partial arc guide bearings

    Exact Error Bound of Cox-Rower Architecture for RNS Arithmetic

    Get PDF
    Residue Number System (RNS) is a method for representing an integer as an n-tuple of its residues with respect to a given base. Since RNS has inherent parallelism, it is actively researched to implement fast public-key cryptography using RNS. This paper derives the exact error bound of approximation on the Cox-Rower architecture which was proposed for RNS modular multiplication. This is the tightest bound ever found and enables us to find new parameter sets for the Cox-Rower architecture, which cannot be found with old bounds

    Association of elevated plasma B-type natriuretic peptide levels with paroxysmal atrial fibrillation in patients with nonobstructive hypertrophic cardiomyopathy

    Get PDF
    Objectives: To investigate the relationship between the plasma B-type natriuretic peptide (BNP) level and the occurrence of atrial fibrillation (AF) in nonobstructive hypertrophic cardiomyopathy (HCM) patients. Methods: Patients (n=97) were classified into chronic AF (CAF; n=14), paroxysmal AF (PAF; n=18) and normal sinus rhythm (NSR; n=65) groups. The plasma BNP values were analyzed with logarithmic transformation. Results: The PAF group showed significantly higher plasma BNP levels than the NSR group [mean (range; -1 SD and +1 SD); 248.3 (143.5, 429.5) vs. 78.2 (27.9, 218.8 ng/L), p Conclusions: The present study indicated that plasma BNP level is clinically useful for identification of nonobstructive HCM patients who have a risk of PAF.</p

    Is this a new type of primary prosopagnosia, both progressive and apperceptive?

    Get PDF
    Prosopagnosia, the inability to recognize faces, has a history going back to Charcot and Hughlings-Jackson, but was first named by Bodamer in 1947. Its anatomical loci are still unclear. However, progressive prosopagnosia is normally linked to right dominant temporal lobe atrophy, and diagnosed as part of frontotemporal lobar degeneration. Here we report a case of prosopagnosia linked to posterior cortical atrophy. Although case reports of posterior cortical atrophy-prosopagnosia do already exist, it is normally described as an accessory symptom. The interest of our own posterior cortical atrophy patient, possibly the first such case, is that he had a rare apperceptive type of prosopagnosia unrelated to the associative, frontotemporal lobar degeneration-type

    Fournier’s gangrene in elderly patient : report of a case

    Get PDF
    Fournier’s gangrene (FG) is rapidly progressing acute gangrenous infection of the anorectal and urogenital area. FG needs precocious diagnosis and aggressive treatment with the use of wide spectrum antibioticus and surgical debridement. In our case, a 91-year-old Japanese female who had rehabilitation after treatment of pneumonia and her past history was rheumatoid arthritis treated with steroid and chronic heart failure. Her activities of daily living was bedridden with dementia. Necrotic skin was observed in urogenital and anorectal area and skin redness enlarged to the hip with high fever. Surgical debridement was performed. Both Peptostreptococcus Sp. and Fusobacterium Sp. was cultured from resected necrotic tissue. We used antibioticus, PAPM and PIPC, which had sensitivity for them. But unfortunately, disseminated intravascular coagulation occurred after 4th day of operation, and finally she died after 10th day of operation. We discussed the treatment for FG in patient with complication

    High serum levels of both carcinoembryonic antigen and carbohydrate antigen 19-9 in a patient with sigmoid colon cancer without metastasis

    Get PDF
    Carcinoembryonic antigen (CEA) and carbohydrate antigen (CA)19-9 are well known as the most common tumor markers of colon cancer, and levels are used not only for preoperative assessment of extent and outcome of cancer, but also postoperative monitoring of recurrence. We encountered a patient with sigmoid colon cancer showing abnormally high serum levels of CEA (311.1 ng/ml) and CA19-9 (5731.2 U/ml) preoperatively. We could not detect any metastases on computed tomography (CT) or 18F-fluorodeoxyglucose positron emission tomography/CT. Sigmoidectomy and lymph node dissection were performed. Pathological analysis revealed well-differentiated tubular adenocarcinoma of the sigmoid colon with cancer cells infiltrating to the subserosa, but no lymph node metastases. As of postoperative day 60, serum levels of CEA and CA19-9 were 3.4 ng/ml and 9.2 U/ml, respectively, without any further anti-tumor treatment. This represents a rare case of sigmoid colon cancer with high levels of tumor markers in sera that improved following sigmoidectomy without further anti-cancer treatment

    Acute abdomen caused by both acute appendicitis and epididymitis

    Get PDF
    Acute appendicitis often presents as right lower quadrant (RLQ) pain, severe tenderness at the point of McBurny or Lanz, and Blumberg’s sign. Scrotal events with appendicitis are very rare. In our case, a 63-year-old Japanese man presented with severe RLQ pain and high fever. Physical examination revealed severe tenderness (including both points of McBurny and Lanz) and Blumberg’s sign. The scrotum was slightly swollen and showed local heat with severe testicular pain. Abdominal computed tomography revealed ascites in a pelvic space and the right side of the spermatic cord was swollen. Emergency operation was performed and the final diagnosis was catarrhal appendicitis and acute epididymitis. This is the first report of acute appendicitis concomitant with acute epididymitis

    Impaired cognitive modification for estimating time duration in Parkinson’s disease

    Get PDF
    Parkinson\u27s disease (PD) is associated with various cognitive impairments. However, the nature of cognitive modification in patients with PD remains to be elucidated. In the present study, we examined whether patients with PD could correct and maintain subjective time duration and line length estimation. After training sessions, in which participants repeatedly memorized either a duration or a length, we compared a learning performance in 20 PD patients with 20 healthy controls. In the case of duration in the PD patients, the learned durations immediately returned to baseline of pre-training within a few minutes. However, the patients’ ability to learn length estimation remained unimpaired. In contrast, healthy controls were able to retain the learned duration and length estimations. Time compression in PD\u27s internal clock may become entrained to their altered duration estimation even after learning of accurate time duration. These deficits may be associated with disrupting cognitive modification in PD
    • …
    corecore