• 한국분말재료학회지
• /
• 제12권2호
• /
• pp.106-111
• /
• 2005

The effect of post-heat treatment on the coating characteristics and the fatigue strength of the gas flame thermally sprayed Stellite alloy coatings on $0.35\%$ carbon steel were investigated. The fatigue fracture surfaces of the heat treated samples were observed using SEM (Scanning Electron Microscopy). For as-sprayed samples, there was considerable scattering in the fatigue life due to the presence of the pores in the coating. After the post-heat treatment to improve the microstructural characteristics of the coating layer, the fatigue strength of the specimens was greatly improved, increasing with increasing the coating thickness. For the specimens with the 0.3mm and 0.5mm thick coating, the fatigue cracks originated in the substrate region just below the interface. On the contrary, for the specimens with the 1.0mm thick coating, they nucleated at the pore within the coating, and the fatigue strength was 2.6 times higher than that of the substrate due to the high fatigue resistance of the coating.

• Journal of Contemporary Eastern Asia
• /
• 제19권2호
• /
• pp.84-103
• /
• 2020

Spurred by the ongoing globalization, an increase in mobility has diversified migrant categories and strengthened intercultural rapport. Alongside the "traditional" migrants, "White" (Caucasian) individuals are coming into greater focus of migration studies as "lifestyle migrants". Although White migrations are not a new phenomenon, the deep-seated idea of White supremacy continues to play an important role in contemporary intercultural communication, awarding Whites across communities a "cosmopolitan" status of highly educated cultural elites. As such, the focus of this research is on highly skilled White European migrants, on their subjective experiences of integration in Japan, and whether they perceive Whiteness as an obstacle or an advantage in this process, if integration is desired at all. To discern the connection between race and integration, this research investigates the non-White majority society of Japan as it has established racial hierarchies according to the Western models, consequently influencing the status of its contemporary White immigrants. Privileged, yet singled out as racial and cultural role models, White Europeans' integration seemingly becomes nearly impossible. The data obtained in fifteen semi-structured interviews confirms that Whiteness grants advantages when entering the Japanese job market, but remains an obstacle in everyday community integration. European professionals do not feel accepted and abandon efforts to integrate, if such were made, retreating into "cosmopolitan islets" wherein they renegotiate their White European identities.

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권5호
• /
• pp.1957-1962
• /
• 2012

Bladder cancer is a common malignancy worldwide. Despite the increased use of cisplatin-based combination therapy, the outcomes for patients with advanced disease remain poor. Recently, altered activation of the PI3K/Akt/mTOR pathway has been associated with reduced patient survival and advanced stage of bladder cancer, making its upstream or downstream components attractive targets for therapeutic intervention. In the present study, we showed that treatment with DTCM-glutaramide, a piperidine that targets PDK1, results in reduced proliferation, diminished cell migration and G1 arrest in 5637 and T24 bladder carcinoma cells. Conversely, no apoptosis, necrosis or autophagy were detected after treatment, suggesting that reduced cell numbers in vitro are a result of diminished proliferation rather than cell death. Furthermore previous exposure to 10 ${\mu}g/ml$ DTCM-glutarimide sensitized both cell lines to ionizing radiation. Although more studies are needed to corroborate our findings, our results indicate that PDK1 may be useful as a therapeutic target to prevent progression and abnormal tissue dissemination of urothelial carcinomas.

• Journal of Gastric Cancer
• /
• 제23권2호
• /
• pp.275-288
• /
• 2023

Purpose: This study aimed to examine the effects of 4 main types of gastrectomy for proximal gastric cancer on postoperative symptoms, living status, and quality of life (QOL) using the Postgastrectomy Syndrome Assessment Scale-45 (PGSAS-45). Materials and Methods: We surveyed 1,685 patients with upper one-third gastric cancer who underwent total gastrectomy (TG; n=1,020), proximal gastrectomy (PG; n=518), TG with jejunal pouch reconstruction (TGJP; n=93), or small remnant distal gastrectomy (SRDG; n=54). The 19 main outcome measures (MOMs) of the PGSAS-45 were compared using the analysis of means (ANOM), and the general QOL score was calculated for each gastrectomy type. Results: Patients who underwent TG experienced the lowest postoperative QOL. ANOM showed that 10 MOMs were worse in patients with TG. Four MOMs improved in patients with PG, while 1 worsened. One MOM was improved in patients with TGJP versus 8 MOMs in patients with SRDG. The general QOL scores were as follows: SRDG (+39 points), TGJP (+6 points), PG (+3 points), and TG (-1 point). Conclusions: The TG group experienced the greatest decline in postoperative QOL. SRDG and PG, which preserve part of the stomach without compromising curability, and TGJP, which is used when TG is required, enhance the postoperative QOL of patients with proximal gastric cancer. When selecting the optimal gastrectomy method, it is essential to understand the characteristics of each and actively incorporate guidance to improve postoperative QOL.

• 한국의학물리학회:학술대회논문집
• /
• 한국의학물리학회 2002년도 Proceedings
• /
• pp.144-145
• /
• 2002

Stereotactic radiotherapy is required to irradiate a small tumor accurately. The radiotherapy showing improves when making an accidental error little boundlessly. It is performed according to treatment planning that is established by the outside landmark of head. At present, when stereotactic radiotherapy for a head is done, the Leksell Flame is fixed on the head, and positioning based on the point and so on which it is in that fixed implement is performed. However, there are problems on the method done at present in the point such as reappearance when the fractionated irradiation method in which the Leksell Flame is removed and installed at every treatment is done because there are landmarks outside the head. Landmarks in the skull were decided, and that precision was examined for the purpose of the improvement of the radiation therapeutic gain. Linac-graphy with longitudinal and lateral view were taken with 6 MV photon beams. A distance to base point inside the skull, each film measured the angle from a center of the small irradiation field, and comparison was done. From the results, a large accidental error wasn't seen as a result of the measurement by every film. Stereotactic radiotherapy for a head treatment had an accidental error of about several millimeters when treatment positioning was done. Therefore, it was thought that there was no problem about an accidental error to arise by putting a landmark in the skull. And, because an accidental error was easy to discover, we thought that modification could be done easily. It was suggested that a landmark in the skull on thus study were useful for improvement of stereotactic radiotherapy.

• Archives of Plastic Surgery
• /
• 제41권1호
• /
• pp.50-56
• /
• 2014

Background The aim of this study was to determine the efficacy of lateral intercostal artery perforator-based adipofascial free flaps for facial reconstruction in patients with facial soft tissue deficiency. Methods We conducted a retrospective study of five consecutive patients diagnosed with facial soft tissue deficiency who underwent operations between July 2006 and November 2011. Flap design included the area containing the perforators. A linear incision was made along the rib, which had the main intercostal pedicle. First, we dissected below Scarpa's fascia as the dorsal limit of the flap. Then, the adipofascial flap was elevated from the medial to the lateral side, including the perforator that pierces the serratus anterior muscle after emerging from the lateral intercostal artery. After confirming the location of the perforator, pedicle dissection was performed dorsally. Results Dominant perforators were located on the sixth to eighth intercostal space, and more than four perforators were found in fresh-cadaver angiography. In the clinical case series, the seventh or eighth intercostal artery perforators were used for the free flaps. The mean diameter of the pedicle artery was 1.36 mm, and the mean pedicle length was 61.4 mm. There was one case of partial fat necrosis. No severe complications occurred. Conclusions This is the first study of facial contour reconstruction using lateral intercostal artery perforator-based adipofascial free flaps. The use of this type of flap was effective and can be considered a good alternative for restoring facial symmetry in patients with severe facial soft tissue deficiency.

• Journal of Communications and Networks
• /
• 제12권1호
• /
• pp.52-66
• /
• 2010

Since large objects consume substantial resources, web proxy caching incurs a fundamental trade-off between performance (i.e., hit-ratio and latency) and overhead (i.e., resource usage), in terms of caching and relaying large objects to users. This paper investigates how and to what extent the current dedicated-server based web proxy caching scheme is affected by large file transfers in a high bandwidth campus network environment. We use a series of trace-based performance analyses and profiling of various resource components in our experimental squid proxy cache server. Large file transfers often overwhelm our cache server. This causes a bottleneck in a web network, by saturating the network bandwidth of the cache server. Due to the requests for large objects, response times required for delivery of concurrently requested small objects increase, by a factor as high as a few million, in the worst cases. We argue that this cache bandwidth bottleneck problem is due to the fundamental limitations of the current centralized web proxy caching model that scales poorly when there are a limited amount of dedicated resources. This is a serious threat to the viability of the current web proxy caching model, particularly in a high bandwidth access network, since it leads to sporadic disconnections of the downstream access network from the global web network. We propose a peer-to-peer cooperative web caching scheme to address the cache bandwidth bottleneck problem. We show that it performs the task of caching and delivery of large objects in an efficient and cost-effective manner, without generating significant overheads for participating peers.

• Smart Structures and Systems
• /
• 제33권2호
• /
• pp.119-131
• /
• 2024

Drift angle is a significant index for diagnosing post-event structures. A common way to estimate this drift response is by using modal parameters identified under natural excitations. Although the modal parameters of shear structures cannot be identified accurately in the real environment, the identification error has little impact on the estimation when measurements from several floors are used. However, the estimation accuracy falls dramatically when there is only one accelerometer. This paper describes the susceptibility of single sensor identification to modelling error and simulations that preliminarily verified this characteristic. To make a robust evaluation from measurements of one floor of shear structures based on imprecisely identified parameters, a novel scheme is devised to approximately correct the mode shapes with respect to fictitious frequencies generated with a genetic algorithm; in particular, the scheme uses constrained minimization to take both the mathematical aspect and the realistic aspect of the mode shapes into account. The algorithm was validated by using a full-scale shear building. The differences between single-sensor and multiple-sensor estimations were analyzed. It was found that, as the number of accelerometers decreases, the error rises due to insufficient data and becomes very high when there is only one sensor. Moreover, when measurements for only one floor are available, the proposed method yields more precise and appropriate mode shapes, leading to a better estimation on the drift angle of the lower floors compared with a method designed for multiple sensors. As well, it is shown that the reduction in space complexity is offset by increasing the computation complexity.

• Industrial Engineering and Management Systems
• /
• 제10권3호
• /
• pp.209-220
• /
• 2011

Self-tapping screws have some operational peculiarities. In spite of their economical advantage that requires no prior tapping operation, a weakness of self-tapping screw-tightening operations is that screws can easily be tightened at a non-right angle, thus resulting in an improper tightening strength. Increases in outsourced workers have reduced labor costs, but the accompanying high worker fluidity means that new workers are more frequently introduced into factories. It is necessary to train new workers for self-tapping screw-tightening operations, which occupies a considerable portion of ordinary assembly works. The purpose of this study is to develop and implement a skill transfer system for the operation. This study (1) proposes a set of characteristic values for evaluating the quality of the operation and develops a device that can measure these values; (2) proposes criteria for evaluating the resultant quality of the tightening; and (3) develops a skill training system for better work performance. Firstly, sets of characteristic values for evaluating the quality of the operation, namely, torque, vertical pressure forces and horizontal vibration forces, are proposed. A device that can measure these values is developed. Secondly, criteria for evaluating the resultant quality of the tightening are identified, involving tightening torque, maximum vertical pressure and timing, vibration area during the processing and tightening period, and work angle. By using such parameters, workers with the proper aptitude can be identified. Thirdly, a skill training system for the operation is developed. It consists of screwdriver operation training and screw-tightening training with feedback information about the results of the operation. Finally, the validity of the training system is experimentally verified using new operators and actual workers.

• 사상체질의학회지
• /
• 제25권4호
• /
• pp.289-296
• /
• 2013

Objectives This study was aimed to validate Sasang Constitution Questionnaire for Japanese (SSCQ-J). Methods Sasang Constitution Questionnaire for Patients (SSCQ-P) was developed by joint researches between the Society of Sasang Constitutional Medicine and Korea Institute of Oriental Medicine. We translated SSCQ-P into Japanese and modified some items of that for Japanese. By getting approval from the Institutional Review Board（IRB）of School of Medicine, Keio University, we conducted a questionnaire survey of patients who visited Oriental Medicine Center from early January until mid-February 2011. The total of 364 patients filled out that Questionnaire and gave an interview with a Sasang constitution specialist. Using this Questionnaire data, we made Sasang constitutional classification functions and calculated diagnostic accuracy rate of SSCQ-J using discrimination analysis. Results 1. Male group's diagnostic accuracy rate of SSCQ-J was 77.01% and female was 78.10%. 2. Diagnostic accuracy of SSCQ-J was a little higher than SSCQ-P Conclusions 1. SSCQ-J can be considered to have good discriminant power compared with SSCQ-P 2. Further research with SSCQ-J will be helpful in the comparison study on the usual symptoms between Korean and Japanese as well as development of good discriminant function.