• Korean Journal of Clinical Pharmacy
• /
• v.3 no.1
• /
• pp.15-20
• /
• 1993

The ability to precisely predict serum digoxin concentration using 7 published methods in a group of 50 patients was undertaken. Two methods of estimating creatinine clearance and two estimates of lean body weight were employed as input variables using the 7 dosing methods. TDX was used to determine the nadir SDCs(serum digoxin concentrations) in 50 in patients meeting predetermined study criteria. All patients, whose ages ranged 19-71 years, had steady-state digoxin levels, were in oral digoxin, and were free from liver dysfunction, thyroid dysfunction and renal failure. The correlation coefficients(r) of predicted versus observed SDCs were determined,. and mean error(ME) was determined for each method to reflect bias, respectively. No substantial differance in predictive reliabliity was evident among the methods studied in total group. Poor correlations existed between predicted and observed SDCs(r<0.4) and these correlations were not significantly affected by age and gender. But relatively higher correlation and lower ME was founded for the CHF group in Jelliffe method(r=0.5, p<0.05).

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.28 no.4
• /
• pp.455-461
• /
• 2010

It is one among very important works to detect change in urban area for effectively maintaining city. But, recently it is become more difficult to extract various changes using traditional method based on orthophotos because objects in urban area get higher and become more complex. To resolve these problems, we introduce new digital imagining system Pictometry which can acquire images of five directions (oblique and nadir). In this study, we compared the digital interpretation results based on Pictometry to the results from traditional method. As a result, Pictometry showed the good results in change detection of urban area.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.46 no.9
• /
• pp.760-766
• /
• 2018

Due to external disturbances on the satellite, unwanted momentum is accumulated on reaction wheels. To remove this momentum, three magnetic torquers which are installed along the satellite's axes are used. The magnetic torquers generated torque indirectly by interactions with the earth's magnetic field. Thus, during momentum dumping, we should consider both the magnetic torquer and the earth's magnetic field generated on the magnetic torquers at the same time. When low earth orbit satellite with high inclination angle holds nadir pointing attitude, weak earth's magnetic field is generated along the satellite's pitch axis. In this case, one magnetic torquer is overloaded and momentum dumping performance is degraded. This research will review the method to improve the momentum dumping performance by adjusting magnetic torquers arrangement.

• Korean Journal of Remote Sensing
• /
• v.15 no.4
• /
• pp.367-375
• /
• 1999

This paper describes the development, operations, and applications of ROCSAT-l and its Ocean Color Imager (OCI) remote-sensing payload. It is the first satellite program of NSPO. The satellite was successfully launched by Lockheed Martin's Athena on January 26, 1999 from Cape Canaveral, Florida. ROCSAT-l is a Low Earth Orbit (LEO) experimental satellite. Its circular orbit has an altitude of 600km and an inclination angle of 35 degrees. The satellite is designed to carry out scientific research missions, including ocean color imaging, experiments on ionospheric plasma and electrodynamics, and experiments using Ka-band (20∼30GHz) communication payloads. The OCI payload is utilized to observe the ocean color in 7 bands (including one redundant band) of Visible and Near-Infrared (434nm∼889nm) range with the resolution of 800m at nadir and the swath of 702km. It employs high performance telecentric optics, push-broom scanning method using Charge Coupled Devices (CCD) and large-scale integrated circuit chips. The water leaving radiance is estimated from the total inputs to the OCI, including the atmospheric scattering. The post-process estimates the water leaving radiance and generates different end products. The OCI has taken images since February 1999 after completing the early orbit checkout. Analyses have been performed to evaluate the performances of the instrument in orbit and to compare them with the pre-launch test results. This paper also briefly describes the ROCSAT-l mission operations. The spacecraft operating modes and ROCSAT Ground Segment operations are delineated, and the overall initial operations of ROCSAT-l are summarized.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.17 no.2
• /
• pp.335-352
• /
• 2023

When solving multi-objective optimization problems, the blindness of the evolution direction of the population gradually emerges with the increase in the number of objectives, and there are also problems of convergence and diversity that are difficult to balance. The many- objective optimization problem makes some classic multi-objective optimization algorithms face challenges due to the huge objective space. The sine cosine algorithm is a new type of natural simulation optimization algorithm, which uses the sine and cosine mathematical model to solve the optimization problem. In this paper, a knee-driven many-objective sine-cosine algorithm (MaSCA-KD) is proposed. First, the Latin hypercube population initialization strategy is used to generate the initial population, in order to ensure that the population is evenly distributed in the decision space. Secondly, special points in the population, such as nadir point and knee points, are adopted to increase selection pressure and guide population evolution. In the process of environmental selection, the diversity of the population is promoted through diversity criteria. Through the above strategies, the balance of population convergence and diversity is achieved. Experimental research on the WFG series of benchmark problems shows that the MaSCA-KD algorithm has a certain degree of competitiveness compared with the existing algorithms. The algorithm has good performance and can be used as an alternative tool for many-objective optimization problems.

• Journal of the Korea Institute of Building Construction
• /
• v.23 no.5
• /
• pp.519-526
• /
• 2023

This research endeavors to explore the nuances in apparent resistivity readings in concrete specimens due to the proximity of embedded reinforcement. To systematically gauge this, concrete samples incorporating singular and paired rebars were meticulously crafted. These rebars were strategically positioned at intervals of 0.03m, 0.04m, and 0.05m from each specimen's midpoint. Subsequent resistivity assessments were conducted at 0.01m increments up to the predetermined rebar location for each sample. A consistent observation was the nadir in apparent resistivity manifesting at the rebar's epicenter. Notably, dual-rebar configurations registered lower resistivity values at this central juncture compared to their single-rebar counterparts. This metric underscores the palpable impact of surrounding reinforcement on resistivity readings. Further, as the spatial separation between rebars increased, the distinctness in their locational identification via resistivity became increasingly pronounced.

• Tuberculosis and Respiratory Diseases
• /
• v.42 no.2
• /
• pp.206-217
• /
• 1995

Background: In patients with obstructive sleep apnea syndrome(OSAS), there are several factors increasing upper airway resistance and there is a predisposition to compromised respiratory function during waking and sleep related to constitutional factors including a tendency to obesity. Several recent studies have suggested a possible relationship between sleep apnea(SA) and systemic hypertension. But the possible pathophysiologic link between SA and hypertension is still unclear. In this study, we have examined the relationship among age, body mass index(BMI), pulmonary function parameters and polysomnographic data in patients with OSAS. And also we tried to know the difference among these parameters between hypertensive OSAS and normotensive OSAS patients. Methods: Patients underwent a full night of polysomnography and measured pulmonary function during waking. OSAS was diagnosed if patients had more than 5 apneas per hour(apnea index, AI). A careful history of previously known or present hypertension was obtained from each patient, and patients with systolic blood pressure $\geq$ 160mmHg and/or diastolic blood pressure $\geq$ 95mmHg were classified as hypertensives. Results: The noctural nadir of arterial oxygen saturation($SaO_2$ nadir) was negatively related to AI and respiratory disturbance index(RDI), and the degree of noctural oxygen desaturation(DOD) was positively related to AI and RDI. BMI contributed to AI, RDI, $SaO_2$ nadir and DOD values. And also BMI contributed to $FEV_1,\;FEV_1/FVC$ and DLco values. There was a correlation between airway resistance(Raw) and AI, and there was a inverse correlation between DLco and DOD. But there was no difference among these parameters between hypertensive OSAS and normotensive OSAS patients. Conclusion: The obesity contributed to the compromised respiratory function and the severity of OSAS. AI and RDI were important factors in the severity of hypoxia during sleep. The measurement of pulmonary function parameters including Raw and DLco may be helpful in the prediction and assessment of OSAS patients. But we could not find clear difference between hypertensive and normotensive OSAS patients.

• Tuberculosis and Respiratory Diseases
• /
• v.45 no.1
• /
• pp.153-168
• /
• 1998

Background: The existing data indicate that obstructive sleep apnea syndrome contributes to the development of cardiovascular dysfunction such as systemic hypertension and cardiac arrhythmias, and the cardiovascular dysfunction has a major effect on high long-term mortality rate in obstructive sleep apnea syndrome patients. To a large extent the various studies have helped to clarify the pathophysiology of obstructive sleep apnea, but many basic questions still remain unanswered. Methods: In this study, the influence of obstructive sleep apnea on systemic blood pressure, cardiac rhythm and urinary catecholamines concentration was evaluated. Over-night polysomnography, 24-hour ambulatory blood pressure and ECG monitoring, and measurement of urinary catecholamines, norepinephrine (UNE) and epinephrine (UEP), during waking and sleep were undertaken in obstructive sleep apnea syndrome patients group (OSAS, n=29) and control group (Control, n=25). Results: 1) In OSAS and Control, UNE and UEP concentrations during sleep were significantly lower than during waking (P<0.01). In UNE concentrations during sleep, OSAS showed higher levels compare to Control (P<0.05). 2) In OSAS, there was a increasing tendency of the number of non-dipper of nocturnal blood pressure compare to Control (P=0.089). 3) In both group (n=54), mean systolic blood pressure during waking and sleep showed significant correlation with polysomnographic data including apnea index (AI), apnea-hypopnea index (AHI), arterial oxygen saturation nadir ($SaO_2$ nadir) and degree of oxygen desaturation (DOD). And UNE concentrations during sleep were correlated with AI, AHI, $SaO_2$ nadir, DOD and mean diastolic blood pressure during sleep. 4) In OSAS with AI>20 (n==14), there was a significant difference of heart rates before, during and after apneic events (P<0.01), and these changes of heart rates were correlated with the duration of apnea (P<0.01). The difference of heart rates between apneic and postapneic period (${\Delta}HR$) was significantly correlated with the difference of arterial oxygen saturation between before and after apneic event (${\Delta}SaO_2$) (r=0.223, P<0.001). 5) There was no significant difference in the incidence of cardiac arrhythmias between OSAS and Control In Control, the incidence of ventricular ectopy during sleep was significantly lower than during waking. But in OSAS, there was no difference between during waking and sleep. Conclusion : These results suggested that recurrent hypoxia and arousals from sleep in patients with obstructive sleep apnea syndrome may increase sympathetic nervous system activity, and recurrent hypoxia and increased sympathetic nervous system activity could contribute to the development of cardiovascular dysfunction including the changes of systemic blood pressure and cardiac function.

• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.4
• /
• pp.555-560
• /
• 2008

The effects of utilizing evaporative cooling system equipped with tunnel ventilation on postpartum ovarian activities, energy balance and milk production of early lactating dairy cows under hot and humid climates were studied from parturition to 22 wk postpartum. Thirty-four crossbred Holstein-Friesian (93.75% HF$\times$.25% Bos indicus) primiparous cows were randomly assigned to one of two groups. Cooled cows (n = 17; treatment) were housed in the tunnel ventilated barn equipped with evaporative cooling system and uncooled (n = 17; control) were housed in the naturally ventilated barn without supplemental cooling system. Cooled cows had greater (p<0.05) dry matter intake and milk production than uncooled cows. Days to the energy balance (EB) nadir did not differ between groups. However, days to equilibrium EB for uncooled cows was longer (p<0.05) than for cooled cows. There was no significant difference in postpartum anovular condition between cooled and uncooled cows. The interval from parturition to first postpartum ovulation did not differ between groups ($31.4{\pm}4.3$ and $26.1{\pm}3.6$ day, respectively). These results suggest that the evaporative cooling and tunnel ventilation has the potential to decrease the severity of heat stress and improve both milk production and metabolic efficiency during early lactation without affecting reproductive function in dairy cows under hot and humid climates.

• Radiation Oncology Journal
• /
• v.34 no.4
• /
• pp.260-264
• /
• 2016

Purpose: Stereotactic body radiotherapy (SBRT) takes advantage of low ${\alpha}/{\beta}$ ratio of prostate cancer to deliver a large dose in few fractions. We examined clinical outcomes of SBRT using CyberKnife for the treatment of low- and intermediate-risk prostate cancer. Materials and Methods: This study was based on a retrospective analysis of the 33 patients treated with SBRT using CyberKnife for localized prostate cancer (27.3% in low-risk and 72.7% in intermediate-risk). Total dose of 36.25 Gy in 5 fractions of 7.25 Gy were administered. The acute and late toxicities were recorded using the Radiation Therapy Oncology Group scale. Prostate-specific antigen (PSA) response was monitored. Results: Thirty-three patients with a median 51 months (range, 6 to 71 months) follow-up were analyzed. There was no biochemical failure. Median PSA nadir was 0.27 ng/mL at median 33 months and PSA bounce occurred in 30.3% (n = 10) of patients at median at median 10.5 months after SBRT. No grade 3 acute toxicity was noted. The 18.2% of the patients had acute grade 2 genitourinary (GU) toxicities and 21.2% had acute grade 2 gastrointestinal (GI) toxicities. After follow-up of 2 months, most complications had returned to baseline. There was no grade 3 late GU and GI toxicity. Conclusion: Our experience with SBRT using CyberKnife in low- and intermediate-risk prostate cancer demonstrates favorable efficacy and toxicity. Further studies with more patients and longer follow-up duration are required.