• Transactions of the Korean Society of Mechanical Engineers
• /
• v.8 no.2
• /
• pp.97-103
• /
• 1984

Post weld heat treatment(PWHT) of weldment of the low alloy steel is carried out to remove residual stress existing in weldment and to improve fracture toughness, but it is often observed that there occurs grain boundary failure and that fracture toughness decreases in weld heat affected zone(HAZ)because of PWHT. In this paper, the effect of heating rate and holding time of PWHT on fracture toughness were evaluated by crack opening displacement (CDD)test and micro-hardness test under the constant stress simulated residual stress in HAZ of Cr-Mo steel. The experimental results are as follow; (1)Transition temperature of weld HAZ after PWHT was dependent upon heating rate greater than holding time, and fracture toughness was decreased with an increase of the heating rate. (2)Softening ration of the notch tip was increased with holding time within one hour and saturated after one hour, but under applied stress it was increasing continuously. (3)The average hardness value in weld HAZ was increased with heating rate of PWHT.

• Journal of Korean Critical Care Nursing
• /
• v.4 no.1
• /
• pp.37-50
• /
• 2011

Purpose: This study is to evaluate the effect of abdominal breathing on postoperative pain, state anxiety, blood pressure, and heart rate of cardiac surgery patients treated in intensive care unit. Methods: A non-synchronized design of nonequivalent control group pre-post test was used. Participants were divided into an experimental group(n=22) and a control group(n=21). Just usual postoperative treatments were provided to the control group, while abdominal breathing interventions were provided to the experimental group, in addition to usual treatments. The intervention was consisted of 4 stages-introductions, breathing perception, breathing training, and closing-and it lasted twelve minutes in total. Pain, state anxiety, blood pressure and heart rate were the dependent variables of the abdominal breathing. Results: Those who carried out abdominal breathing showed a significant reduction in pain, as well as decrease of systolic blood pressure. However, it turned out to have no effect on state anxiety, diastolic blood pressure and heart rate. Conclusion: Abdominal breathing is simple and harmless and is effective for reducing postoperative pain.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.19 no.8
• /
• pp.1940-1949
• /
• 1995

A numerical study for a two dimensional multi-jet with crossflow of the spent fluid has been carried out. Three different distributions of mass-flow rate at 5 jet exits were assumed to see their effects upon the flow characteristics, especially in the jet-flow region. For each distribution, various Reynolds numbers ranging from laminar to turbulent flows were considered. Results show that a fully developed laminar flow exists above a certain Reynolds number whose exact value depends upon the mass flow rate distribution. AS the Reynolds number increases, the flow becomes transitional from downstream and finally a fully developed turbulent flow forms in the jet-flow region. The critical Reynolds number where the fully developed turbulent flow forms is quite dependent upon the distribution of mass-flow rate. One interesting result is that the distribution of the skin friction coefficient along the inpingement plate in the jet-flow region shows a consistent dependency on the Reynolds number, i.e. inversely proportional to the square root of the Reynolds number, regardless of flow regime.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.21 no.9
• /
• pp.947-954
• /
• 2010

The decision of threat target in the MWR(Missile Warning Radar) of GVES(Ground Vehicle Equipment System) such as MBT(Main Battle Tank) is very important. Threat decision is judged by angular rate and the accurate azimuth calculation for good threat decision is very important. The angular rate is dependent upon the direction of an approaching target. The target is classified into a threat or non-threat using a boundary condition of the angular rate. This paper presents the eighth azimuth calculation methods and compares the results.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.15
• /
• pp.6455-6459
• /
• 2014

Background: Nasopharyngeal carcinoma (NPC) is the fourth most common cancer in Malaysia. The objective of this study was to determine the five-year survival rate and median survival time of NPC patients in Hospital Universiti Sains Malaysia (USM). Methods: One hundred and thirty four NPC cases confirmed by histopathology in Hospital USM between $1^{st}$ January 1998 and $31^{st}$ December 2007 that fulfilled the inclusion and exclusion criteria were retrospectively reviewed. Survival time of NPC patients were estimated by Kaplan-Meier survival analysis. Log-rank tests were performed to compare survival of cases among presenting symptoms, WHO type, TNM classification and treatment modalities. Results: The overall five-year survival rate of NPC patients was 38.0% (95% confidence interval (CI): 29.1, 46.9). The overall median survival time of NPC patients was 31.30 months (95%CI: 23.76, 38.84). The significant factors that altered the survival rate and time were age (p=0.041), cranial nerve involvement (p=0.012), stage (p=0.002), metastases (p=0.008) and treatment (p<0.001). Conclusion: The median survival of NPC patients is significantly longer for age ${\leq}50$ years, no cranial nerve involvement, and early stage and is dependent on treatment modalities.

• The Journal of Industrial Distribution & Business
• /
• v.9 no.7
• /
• pp.33-42
• /
• 2018

Purpose - This paper aims to verify whether the Fisher effect and the international Fisher effect are significant between China and South Korea in the long and short run, respectively. Research design, data, and methodology - The annual and monthly data, respectively, are employed to conduct an empirical estimation under the fully modified ordinary least squares(FMOLS). The nominal interest rate is treated as an independent variable. The inflation rate is treated as a dependent variable. Results - The results exhibit whenever in the long or short run, the Fisher effect exists in China and South Korea. However, the Fisher effect in South Korea is more significant than that of in China. Meanwhile, an empirical analysis is also preformed to investigate the long-run and the short-run international Fisher effect between China and South Korea. The deviation from the equilibrium relationship is that the commodity market and the Financial market have started to integrate in China. But China's integrated level proved to be relatively lower. Conclusions - To exploit that the Fisher effect and the international Fisher effect hold between China and South Korea can help both countries deal with the sufferings from integration of the commodity market and the financial market.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.15 no.5
• /
• pp.353-363
• /
• 1990

This paper analyzes effect of Data Bit Jitter(DBJ) on the Bit Slip Rate(BSR) of the receiver Data Tracking Loop(DTL). In particular, we point out the characteristic jitter parameters that can be used to estimate the BSR performance for the low frequency parts respectively. We also propose a new format for the DBJ specification, which is more sophisticated than the conventional method but is believed to be more practical and accurate in predicting DBJ effect on the receiver BSR performance. In the proposed method, receive dependent parameters are identified and weighting between different parts of jitter spectrum are properly considered.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.07a
• /
• pp.58-62
• /
• 2003

Silicon carbide (SiC) was etched in a $NF_3/CH_4$ inductively coupled plasma. The etch process was modeled by using a neural network called generalized regression neural network (GRNN). For modeling, the process was characterized by a $2^4$ full factorial experiment with one center point. To test model appropriateness, additional test data of 16 experiments were conducted. Particularly, the GRNN predictive capability was drastically improved by a genetic algorithm (GA). This was demonstrated by an improvement of more than 80% compared to a conventionally obtained model. Predicted model behaviors were highly consistent with actual measurements. From the optimized model, several plots were generated to examine etch rate variation under various plasma conditions. Unlike the typical behavior, the etch rate variation was quite different depending on the bias power Under lower bias powers, the source power effect was strongly dependent on induced dc bias. The etch rate was strongly correated to the do bias induced by the gas ratio. Particularly, the etch rate variation with the bias power at different gas ratio seemed to be limited by the etchant supply.

• Journal of Preventive Medicine and Public Health
• /
• v.26 no.3 s.43
• /
• pp.430-441
• /
• 1993

The objectives of this study are two-fold : to identify geographic variations in the rate of tonsillectomy and adenoidectomy (T&A) and appendectomy and analyze the socioeconomic variables and health resources which affect geographic variation in the rate. The nationwide three month's cases of the two surgical procedures in 1991 are obtained from the record of the National Federation of Medical Insurance. The analysis shows two to ten-fold variations in the regional rates for the performance of two common procedures such as T&A and appendectomy. T&A shows a bigger regional variations than appendectomy. As a result of multiple regression, the factor of bed supply has been found significant for the dependent variable of the rate of T&A. The finding of large variations in the rate of surgical procedures throughout the country would have important implications for allocating scarce resources and managing quality of care. Further analysis is needed for the elaboration of the above implications.

• Korean Journal of Veterinary Research
• /
• v.39 no.4
• /
• pp.710-714
• /
• 1999

In veterinary medicine amitraz has been used as an insecticide to eliminate mites, lice, and ticks in dogs, cats, goats, swine and cattle. We performed the experiment on bradycardiac effect of arnitraz in rabbits. Under anesthetized with urethane (1g/kg, 25% w/v, SC), the femoral artery was cannulated by a polyvinyl tube which was connected with pressure transducer for continuous measurement of heart rate. Amitraz (0.5-2.5mg/kg, IV) reduced the heart rate in a dose-dependent manner. Pretreatment of yohimbine (2.0mg/kg) or atropine (2.0mg/kg and 4.0mg/kg) affected the response of amitraz but pretreatment of prazosin (0.5mg/kg) or propranolol (1.0mg/kg) did not. Moreover, the effect of amitraz was blocked by vagotomy. The result of our experiment suggest that amitraz may reduce the heart rate by increasing acetylcholine through activating vagal nerves and ${\alpha}_2$-adrenoceptors could be involved in activating vagal nerves.