• Journal of Chest Surgery
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• 제24권4호
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• pp.345-351
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• 1991

The myocardial temperature was monitored in 19 patients of open heart surgery using the Shiley myocardial temperature probe in Department of Thoracic and Cardiovascular Surgery, Yeungnam University Hospital. The myocardial temperature were measured time-wise: initial and 15 minutes following the infusion of the cardioplegic solution into the aortic root and upon reinfusion, which is 30 minutes apart from the initial. The measurements were made in the anterior wall of the right ventricle, the posterior wall of the left ventricle and the interventricular septum. Immediately after initial infusion, the temperature of the right ventricle[10.7 $\pm$4.3oC] was the lowest and that of the left ventricle[12.9$\pm$3.9 oC] the highest in the mean values among all 19 patients. However, no significant differences were noted among the different regions. At 15 minutes after infusion, the lowest temperature was in the right ventricle[17.5$\pm$5.1 oC], followed by interventricular septum[17.9$\pm$2.9 oC], and left ventricle[21.4$\pm$2.5 oC]. At 30 minutes after infusion, the lowest temperature was measured in the interventricular septum[13.6$\pm$2.7 oC ], followed by right ventricle[13.8$\pm$4.0 oC] and left ventricle[14.5$\pm$4.5 oC ]. Evaluating changes of myocardial temperature according to postinfusion time, the temperature at 15 minutes after infusion showed significant increase as compared with that immediately after the infusion in all three regions[p<0.05] and the temperature at 30 minutes after infusion showed significant decrease as compared with that at 15 minutes after the infusion in the left ventricle and the interventricular septum[p<0.05]. The left ventricle was rewarmed most rapidly and its temperature the highest in the mean values, Accordingly, the maintenance of optimal hypothermia of the left ventricle indicated a very careful factor in myocardial protection.

• Journal of Chest Surgery
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• 제33권10호
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• pp.785-791
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• 2000

Left ventricular dysfuction is common in immediate postoperative periods after surgical correction of heart diseases with chronic left ventricular volume overload. We speculated postoperative changes of left ventricular volume and unction in patients with patent ductus osus(PDA) who had underwent surgical repair at ages older than 16 years. Factors influencing postoperative left ventricular volume and function were also analyzed. Material and Method: From August 1989 to August 1999 thirty-siz adult patients with PDA 28 females and 8 males. were enrolled in this study. Their age ranged from 16 years to 57 years(mean :32 years). Types of surgical repair were division with primary closure in 22, division with patch closure in 6, internal obliteration using cardiopulmonary bypass in 4 and ligation in 4. Aortic clamping was combined during surgical repair in 22(61%) and cardiopulmonary bypass was used in 8(22%) Two-dimensional echocardiography studies were performed in 34(94%) preoperatively and in 25(66%) immediate postoperatively to assess postoperative changes of left ventricular internal dimensions. left ventricular volume and ejection fraction. Duration of postoperative follow-up ranged from 1 month to 99 months (mean:22 months) and 10 patients underwent 16 echocardiographic evaluation during this period Result : Preoperative and postoperative left ventricular systolic dimensions(LVIDs) were 42$\pm$8.0mm and 42$\pm$8.3mm left ventricular diastolic dimensions(LVIDd) were 64$\pm$10.0mm and 56$\pm$7.4mm left ventricular end systolic volumes(LVESV) were 62$\pm$19cc (z=1.87$\pm$0.06) and 59$\pm$24cc(z=1.78$\pm$0.08) left ventricular end diastolic volumes(LVEDL) were 169$\pm$40cc(z-1.17$\pm$0.1) and 112$\pm$29cc(z=0.85$\pm$0.1) and ejection fractions(EF) were 66$\pm$6.7% and 48$\pm$12.6% respectively. There were statistically significant differences between preoperative and postoperative values in LVDIDd(p=0.001) LVEDV(p=0.001) and EF(p=0.0001) while no significant difference is LVIDs and LVESV. Postoperative depression of ejcection fraction was significantly related with z-score of preoperative LVESV and LVEDV by univariateanalysis while LVEDV only was significant risk factor for postoperative LV dysfunction by multiple regressioin analysis ($\Delta$LVEF=-13.3-4.62$\times$LVEDV(z), p=0.001) During the follow-up periods ejection fractions become normalized in all except one patients. Conclusion ; Left ventricular function is usually deteriorated after the surgical correction of PDA in adult age and preoperative LVEDV is a major determinant of postoperative LV function.

• Journal of the Optical Society of Korea
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• 제13권3호
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• pp.379-385
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• 2009

The vergence control of binocular stereoscopic camera is the most essential factor for acquiring high quality stereoscopic images. In this paper, we proposed a binocular stereoscopic camera vergence control method using disparity information by the simple image processing and estimate the quantity of vergence control using the Lagrange interpolation equation. The method of extracting disparity information through image processing is as follows: first the key-object in left & right images was extracted through labeling of the central area of the image, and then a simple method was used for calculating the disparity value of the same key-object in the labeled left and right images. The vergence control method uses disparity information and keeps the convergence distance of left & right cameras and the distance of the key-object the same. According to the proposed method, variance in the distance of the key-object and application of calculated disparity information of obtained left & right images to the quadratic Lagrange interpolation equation could estimate the quantity of vergence control, which confirmed that the method of stereoscopic camera vergence control can be simplified through experiments on various key-objects and other convergence distance.

• 산업경영시스템학회지
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• 제14권24호
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• pp.123-132
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• 1991

This study deals with the experiment of perceiving visual information according to the positions of vehicle side mirrors. In the design of vehicle, the consideration of safety is very important. Therefore we consider the positions of side mirrors to use visual information effectively which is important factor to driver. This paper presents the position of side mirror to elevate the degree of visual perception for the circumstances of danger by experiments. To exhibit the circumstances of danger. 4 LED(Light Emitted Diode) art located at each side(right. left front. hack) of vehicle. A subject pushes the LED switch to see that if he perceives the circumstance of danger. To record the circumstance of randomly generated danger, computer interface card is used to control 4 LED and swithch on IBM PC/AT Experiments are divided into 2 parts. The 1st experiment present the independence of right & left side mirror. The 2nd experiment present optimal position of right & left side mirror. The vehicle used in experiment is model EL of H Co.. Statistical process of experimental data using SPSS(Statistical Package for Social Sciences)/PC package concludes that 1) the optimal position of right side mirror is 54cm forward of exist position. 2) for the left side mirror, the position of 120cm forward of exist position shows the worst degree of perception. and the optimal position does not exist in statistical meaning.

• 대한두개안면성형외과학회지
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• 제20권4호
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• pp.260-264
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• 2019

Dysplastic nevus is common and affects about 10% of the northern European-descendent population. Studies over the past several decades have identified dysplastic nevi as a risk factor for malignant melanoma. Furthermore, in rare cases, they confirmed that dysplastic nevi have progressed to melanoma. Cases in which dysplastic nevi progressed to malignant melanoma in multiple studies are not uncommon. A 35-year-old woman presented with the major symptom of multiple itchy brown nodules ($2.0cm{\times}1.3cm$) in the left cheek that had first appeared 20 years earlier. Complete excision was performed at the first visit; subsequent biopsy confirmed that they were dysplastic nevi. They recurred three times over 3 years at the same site, all of which were histologically diagnosed as dysplastic nevi. Five years after the final excision, a brownish nodule developed in the left cheek, with others at the left temporal region, right retroauricular region, and left shoulder at the same time. These lesions were histologically diagnosed as malignant melanoma. We experienced a case of malignant melanoma that occurred at the same site after three recurrences of dysplastic nevi. Although rare, the possibility of malignant melanoma should be considered in follow-ups in cases involving repeatedly recurrent dysplastic nevi.

• Journal of Cardiovascular Imaging
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• 제30권1호
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• pp.37-46
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• 2022

BACKGROUND: A body of research advocates the prognostic role and usefulness of the volumetric markers of left atrial (LA) phasic functions in the diagnosis of LA dysfunction. We aimed to determine the independent determinants of the volumetric markers of LA contraction function in candidates for coronary artery bypass graft (CABG) surgery. METHODS: This cross-sectional study enrolled 516 candidates for CABG. The biplane maximal, minimal, and pre-P volumes of the LA were measured with two-dimensional echocardiography, and LA active emptying fraction was calculated. The standardized correlation coefficient for the correlation between each factor and LA active emptying fraction was calculated by using univariate and backward multivariable regression analyses. RESULTS: The multivariable regression analysis demonstrated that the heart rate (β = 0.15; p = 0.001), S (β = 0.09; p = 0.036), E/e' ratio (β = -0.11; p = 0.014), left ventricle (LV) ejection fraction (β = 0.15; p = 0.001), and LA enlargement (β = -0.19; p < 0.001) were the independent determinants of LA active emptying fraction. CONCLUSIONS: The independent determinants of LA contraction function were the heart rate, S, LV ejection fraction, LA enlargement, and E/e' ratio in candidates for CABG surgery.

• Kyungpook Mathematical Journal
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• 제63권4호
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• pp.551-560
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• 2023

In this paper we consider a more general class of centralizers called I-centralizers. More precisely, given a prime ideal P of an arbitrary ring R we establish a connection between certain algebraic identities involving a pair of P-left centralizers and the structure of the factor ring R/P.

• 한국생산제조학회지
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• 제22권3_1spc호
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• pp.489-495
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• 2013

This study analyzed thevariation in the cutting force when the cutting area of a terrace volume is machined, which is generally left after the rough cutting of a sculptured surface. The numerically simulated results for the cutting forces are compared with cutting force measurements by considering the theoretical prediction of the cutting area formation and specific cutting volume. The variation in the cutting force is measured using a dynamometer installed on a machining center for 19 different kinds of test pieces, which are selected according to the variation in the terrace volume factor, tool diameter factor, and cutting depth factor. As a result, it is verified that the cutting forces evaluated by the numerical analysis coincide with the measured cutting forces, and it is proposed as a practical cutting force prediction model.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권8호
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• pp.529-535
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• 2000

In this paper, a current control system of a single phase PWM AC/DC converter using a reduced-order Luenberger observer without source voltage sensors is proposed. The sinusoidal input current and unity input power factor are realised based on the estimated source voltage performed by the reduced-order Luenberger observer using actual currents and DC link voltage. The poles of the reduced-order Luenberger observer are placed in the left half plane of s-plane by the pole-placement method in order to acquire the stability of the observer. The magnitude and the phase of the estimated source voltage are used to accomplish the unity power factor. The proposed method is implemented by DSP(Digital Signal Processor). Experimental Results verify that the reduced-order observer estimates the source voltage without the estimation error and the control system accomplishes the unity power factor, and constant DC link voltage.

• Archives of Plastic Surgery
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• 제37권3호
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• pp.265-270
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• 2010

Purpose: Most of the bilateral structures in our body are not perfectly balanced, such that one side is preferred than the other or it has physiological superiority. Eyes also have an imbalance; the eye with sensory and motional superiority compared to the other is called dominant eye. Authors of this study focused on analyzing the correlation between the dominant eye and levator palpebrae superioris muscle. Methods: The subject of this study was 42 patients with no ptosis and with no past history of blepharoplasty. Hand dominance was identified through questionnaire and dominant eye was identified by hole-in-the-card dominance test (Dolman's test) in all patients. The function of levator palpebrae superioris muscle was measured by MLD (marginal limbal distance). During the measuring procedure, frontalis muscle was not inhibited to avoid the eyelid skin hooding. Results: Out of 42 patients, 27 patients (64.3%) were right ocular dominant, 15 patients (35.7%) were left ocular dominant, 36 patients (85.7%) were right hand dominant and 4 patients (9.5%) were left hand dominant. Out of 27 right ocular dominant patients, right MLD was larger than the left in 26 patients (96.3%). It was larger in average of 0.47 mm (p<0.001) in 27 right ocular dominant patients. Also, left MLD was larger than the right in 11 patients (73.3%) out of 15 left ocular dominant patients. It was larger in average of 0.57 mm (p=0.003) in 27 left ocular dominant patients. MLD on the side of the dominant eye was larger in average of 0.50 mm (p<0.001) than the MLD of non-dominant eye side. Right MLD was larger than the left in average of 0.28mm (p=0.010) in right hand dominant patients, and left MLD was larger than the right in average of 1.15 mm (p=0.025) in left hand dominant patients. Conclusion: The function of levator palpebrae muscle differs in right and left, and the difference correlates with the dominant eye. Also, the function of levator palpebrae muscle is stronger in the dominant eye. We were able to present statistical evidence regarding the difference of the function in right and left levator palpebrae muscle. This may be a factor worth consideration in terms of balancing the eyes during the blepharoplasty.