• Journal of Chest Surgery
• /
• v.15 no.2
• /
• pp.194-203
• /
• 1982

In this investigation we undertook to evaluate the utility of radionuclide cardiac angiography in the detection of cardiac shunts before and after surgical correction. Time-activity curves of ventricles and lungs were evaluated after bolus intravenous injection of 99mTc-human serum albumin in 512 preoperative patients and 551 post-operative patients. Omitting 31 cases of technical failure due to poor bolus, we detected shunts in 459 cases of 481 preoperative evaluations, so the detectability was 95.4%. The cases which couldn`t be detected by this method had small amount of shunt. Also the degree of shunt detected by radioisotope methods were well correlated with oxymetry method. [r=0.89, p<0.01 ] In postoperative evaluations, 18 out of 411 patients with left to right shunt and 10 out of 140 right to left shunt were found to have remnant shunts with radionuclide cardiac angiography. Of the 28 cases with failed operation, 2 were confirmed in reoperation, 2 by cardiac catheterization, 2 by two -dimensional echocardiography. All except one .f these patients had membranous ventricular septal defects and those with left to right shunts had moderate to severe pulmonary hypertension and shunt amount. Also those had larger septal defects than control group. We consider that radionuclide cardiac angiography is a simple and noninvasive method which can show the preoperative diagnosis and postoperative follow up of cardiac shunts.

• Journal of the Korean School Mathematics Society
• /
• v.1 no.1
• /
• pp.131-138
• /
• 1998

The aims of mathematical education are to improve uniformity and rigidity, and to apply to an information age which our society demands. One of the educational aims in the 6th educational curriculum emphasizes on the expansion of mathematical thought and utility, But, The change of contents in the text appears little. This means that mathematical teachers must actively develop the new types of problems. That the interests and concerns about mathematics lose the popularity and students recognize mathematics burdensome is the problems of not only teaching method, unrealistically given problems but abstractiveness and conceptions. Mathematical Modeling is classified exact model, almost exact theory based model and impressive model in accordance with the realistic situation and its equivalent degree of mathematical modeling. Mathematical Modeling is divided into normative model and descriptive model according to contributed roles of mathematics. The Modeling Applied Problems in the present text are exact model and stereotyped problems. That the expansion of mathematical thought in mathematics teaching fell into insignificance appears well in the result of evaluating students. For example, regardless of easy or hard problems, students tend to dislike the new types of mathematical problems which students can solve with simple thought and calculation. The ratings of the right answer tend to remarkably go down. If mathematical teachers entirely treat present situation, and social and scientific situation, students can expand the systematic thought and use the knowledge which is taught in the class. Through these abilities of solving problems, students can cultivate their general thought and systematic thought. So it is absolutely necessary for students to learn the Modeling Applied Problems.

• Proceedings of the KIPE Conference
• /
• 2004.07a
• /
• pp.97-100
• /
• 2004

Our country has depended on fossil fuel very much according to the Increasing of the demand of the electric power. For instance, if the reduction and freezing caused by the warm gas in earth by the regulation of international environment happen in Korea it will bring about the result of weakness in industrial activity. As a result, it will cause many problems to compete an advanced country which wants to connect environment with the activity of industrial product in their country. The photovoltaic system outputs have peak about a half past 13 o'clock(before and after) mainly in a good weather. The output decreases rapidly from a half past 17 o'clock and PV output doesn't work at six o'clock before the sun rises. The outputs of PV system stops at that time. The frequent degree of harmonics in dwelling house which lots of people live has peak from 19 o'clock to 22 o'clock Harmonics mainly happens at least at night. In recent, many researches about power quality has been studying very hard in order to solve the question, the voltage fluctuating and harmonics as one compensator. In this paper, I suggest the algorithm which can increase the power quality as a rate of operation of this system. This algorithm proves to have effectiveness through computer simulation.

• Korean Journal of Veterinary Research
• /
• v.57 no.2
• /
• pp.113-116
• /
• 2017

The aim of this study was to examine normal bronchi in dogs by using virtual bronchoscopy (VB) and to evaluate the utility of VB in clinical practice. The bronchi of six dogs without tracheobronchial disease were visualized by VB. Airways from the tracheal bifurcation to the lobar bronchi were well visualized in all dogs. Segmental and subsegmental bronchi were also well identified, but the degree and number of those varied with dog size. The mean numbers of segmental and subsegmental bronchi identified in the six dogs were 41.83 and 50.17, respectively, whereas, the mean numbers in medium- and large-sized dogs were 55.00 and 82.67, respectively, and in small-sized dogs, the means were 28.67 and 17.67, respectively. Although there were size-dependent differences in VB visualization of the bronchi, it was possible to identify peripheral airways to the subsegmental bronchi level, which can rarely be accomplished via conventional bronchoscopy. VB is the noninvasive method that can be used to examine bronchial anatomy, and our results suggest that VB can be useful for evaluating bronchi, including segmental and subsegmental ones that cannot be examined routinely by conventional bronchoscopy. Thus, VB has potential as an alternative to conventional bronchoscopy in the examination of bronchi in dogs.

• Journal of IKEEE
• /
• v.12 no.2
• /
• pp.87-94
• /
• 2008

Pelvic floor muscle is the main subsystem that maintains urinary continence. It is possible to diagnose the degree of the stress urinary incontinence(SUI) by evaluating the contraction pressure of the pelvic floor muscle. Bio-signal measurement system was developed to measure the contraction pressure. Diagnostic parameters were drawn out by analyzing the measured data. Statistical evaluations were done to classify the all subjects with five groups each has similar characteristics. SUI diagnostic algorithm was implemented to each group separately. The accuracy of the algorithm was about 78.9% and utility was confirmed by clinical trial.

• International Journal of Advanced Culture Technology
• /
• v.8 no.3
• /
• pp.300-306
• /
• 2020

This study analyzes the distributor's inventory model in a two-stage supply chain consisting of the supplier, the distributor and the end customer. The supplier will allow a credit period before the distributor settles the account with him in order to stimulate the demand for the product he produces. It is also assumed that the distributor pays the shipping cost for the order and hence, the distributor's ordering cost consists of a fixed ordering cost and the shipping cost that depend on the order quantity. The availability of the delay in payments from the supplier enables discount of the distributor's selling price from a wider range of the price option in anticipation of increased customer's demand. As a result, the availability of a credit transaction leads to an increase in inventory levels. On the other hand, in the case of deteriorating products in which the utility of the product perish over time, the deterioration rate with time plays a role in reducing inventory levels. In this regard, we analyze the effect of the length of the credit period and the degree of product deterioration on the distributor's inventory level. For the analysis, we formulate the distributor's annual net profit and analyze the effect of the length of credit period and deterioration rate of the product on inventory policy numerically.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.7 no.6
• /
• pp.1146-1152
• /
• 2003

Satellite television receiving antenna is required for watching TV on the vehicles, ship and car. Recently TV is not only facility as getting information but one of utility in our life. In Korea, already on the service multi-channel satellite TV using excellent visibility and sound, and there are many users using now by fixing antenna. On this thesis, developed ship's satellite TV receiving antenna, the azimuth controlling is adopted azimuth information using gyro sensor and differential of receiving signal strength algorithm, and elevation controlling used gimbals. The result of this research is successfully implemented Korean satellite tracking antenna as performance until ${\pm}$30 degree roll and pitch of ship motion.

• Fisheries and Aquatic Sciences
• /
• v.18 no.1
• /
• pp.65-71
• /
• 2015

The functional utility of a transgenic marine medaka Oryzias dancena strain carrying the red fluorescent protein (RFP) gene driven by an endogenous choriogenin H (chgH) promoter was evaluated for its ability to detect waterborne $17{\alpha}$-ethinylestradiol (EE2), a synthetic estrogen derivative. The chgH:rfp transgenic marine medaka larvae showed an age-dependent tendency in the efficiency of EE2-mediated transgene expression, in which transgenic larvae older than 6 days post-hatching displayed a more effective response in their transgene expression to EE2 than did younger hatchlings. During experimental exposures to high concentrations of EE2 (200 to 1,000 ng/L), the transgenic responses in the hatchlings were broadly dose- and duration-dependent. With exposures using lower doses of EE2 (25, 50 and 100 ng/L), EE2-induced transgenic RFP was also observed in the transgenic larvae, although the lower doses required exposure of longer duration. Under the EE2 exposure and microscope assay conditions used in our study, transgenic marine medaka larvae exhibited a similar degree of EE2-mediated RFP phenotype expression at various salinity levels (0, 15 and 30 ppt).

• Journal of Industrial Technology
• /
• v.21 no.A
• /
• pp.7-14
• /
• 2001

In building structure, the story height can be minimized by providing openings in beams which serves for the utility equipments passing through. The dead space in false ceiling thus put to economical use in the form of a substantial reduction in materials and construction cost. In the case of steel structure, there is no critical risk in the structural strength because of reinforcing methods of stiffness and steel plate but in the case of reinforced concrete structure, proper provision should be made in designing these openings, otherwise there is a risk that these opening will possibly weaken the structural strength of the building frame to a critical degree. In this paper, for the numerical analysis of the reinforced concrete beams with circular opening in the web, expecting stress concentration of the circular opening, reinforcing methods were studied. Twenty test pieces with each different reinforcing methods were tested and their resisting forces were defined. From the numerical analysis and test results, the followings were founded;(1)high shear stress distributed around the openings reduce the shearing strength, (2)from the numerical analysis, the maximum tensile stress occurred at opening nodes 1,7, these phenomena were agreed with the test results, (3)reinforcing method around openings have to carried out for stopping diagonal cracks, and (4)both, by steel plate, and wire mesh, are effective reinforcing methods.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.14 no.5
• /
• pp.424-431
• /
• 2004

An implicit direct-time integration method for obtaining transient responses of general dynamic systems is described. The conventional Newmark method cannot be directly applied to state-space first-order differential equations, which contain no explicit acceleration terms. The method proposed here is the state-space Newmark method that incorporates the average velocity concept, and can be applied to an analysis of general dynamic systems that are expressed by state-space first-order differential equations. It is also readily coded into a program. Stability and accuracy analyses indicate that the method is numerically unconditionally stable like the conventional Newmark method, and has a period error of 2nd-order accuracy for small damping and 4th-order for large damping and an amplitude error of 2nd-order, regardless of damping. In addition, its utility and validity are confirmed by two application examples. The results suggest that the proposed state-space Newmark method based on average velocity be generally applied to the analysis of transient responses of general dynamic systems with a high degree of reliability with respect to stability and accuracy.