• Hip & pelvis
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• v.35 no.3
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• pp.164-174
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• 2023

Purpose: This study investigates the relationship between preoperative neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-C-reactive protein ratio (LCR), albumin, and 2-year mortality in elderly patients having hemiarthroplasty for displaced femoral neck fracture (FNF). Materials and Methods: We retrospectively reviewed 284 elderly patients who underwent hemiarthroplasty for Garden type IV FNF from September 2014 to September 2020. Using the receiver operating characteristic curve, optimal cutoff values for LCR, NLR, and albumin were established, and patients were categorized as low or high. Associations with 2-year mortality were evaluated through univariate and multivariate Cox regression analyses. Results: Of the 284 patients, 124 patients (45.9%) died within 2 years post-surgery. The optimal cutoff values were: LCR at 7.758 (specificity 58.5%, sensitivity 25.0%), NLR at 3.854 (specificity 39.2%, sensitivity 40.0%), and albumin at 3.750 (specificity 65.9%, sensitivity 21.9%). Patients with low LCR (<7.758), high NLR (≥3.854), and low albumin (<3.750) had a statistically significant reduced survival time compared to their counterparts. Conclusion: Lower preoperative LCR and albumin levels, along with higher NLR, effectively predict 2-year mortality and 30-day post-surgery complications in elderly patients with Garden type IV FNF undergoing hemiarthroplasty.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.357-360
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• 1999

A 20 MHz CMOS continuous low-pass filter using simulated floating inductor consisted of two fully-differential transconductors and a capacitor is presented. The theory of operation is described and simulation results show close agreement between predicted behaviour and experimential performance. Simulation results show that the filter has ripple bandwidth of 22 MHz, pass-band ripple of 0.36 ㏈. and cutoff frequency of 26 MHz at supplay voltage of $\pm$3 V. The power dissipation is 19.2 ㎽.

• IE interfaces
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• v.8 no.2
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• pp.151-159
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• 1995

Two-dimensional cutting stock problem is to find a waste-minimizing method of cutting a single rectangular plane into a number of smaller pieces of known dimensions. In practice, besides wastes, setup cost taken during adjusting is of an important concern. We suggest 2-phased guillotine cutting method as a solution to the problem which minimize wastes and setup costs. Also, in order to reduce the computing time we apply techniques of discretization, cutoff, median. Experimental results show good performance of our algorithm.

• Korean Journal of Optics and Photonics
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• v.5 no.2
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• pp.252-259
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• 1994

The method of calculating overlap dispersion caused by group velocity mismatch between uv and visible pulses in ultrafast pump-probe experiments is presented to discuss limitations of the time resolution and signal intensity. The calculations show arrangements using a single focusing lens shall result in undesirable time resolution and low signal intensity. Achromatic doublets result in unrealistic solutions. However, dramatic improvement in the time resolution and signal intensity is expected in the optical arrangements using separate lens for each pulse and in the arrangements using a cutoff secondary lens with a main lens. lens.

• Journal of Chest Surgery
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• v.53 no.5
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• pp.297-300
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• 2020

Background: This study aimed to assess the effect of vessel size and flow characteristics on the maturation of autogenous radiocephalic arteriovenous fistulae (RCAVFs). Methods: We retrospectively reviewed records of patients undergoing RCAVF creation at a single medical center from January 2013 to December 2019. Operative variables were compared between patients whose fistulae matured and those whose fistulae failed to mature. Results: Overall, 152 patients (33 of whom were women) with a mean age of 62.6±13.6 years underwent RCAVF creation; functional maturation was achieved in 123. No statistically significant differences were observed between patients in whom maturation was or was not achieved in terms of the following variables: female sex (20.3% vs. 25.0%), radial artery size (2.5 vs. 2.4 mm), and pulsatility index (0.69 vs. 0.62). Low intraoperative transit time flowmetry (TTF; 150.4 vs. 98.1 mL/min) and small vein size (2.4 vs. 2.0 mm) were associated with failure of maturation. The best cutoff diameter for RCAVF TTF and cephalic vein size were 105 mL/min and 2.45 mm, respectively. Conclusion: In patients who undergo RCAVF creation, vein diameter on preoperative ultrasonography and intraoperative TTF are predictors of functional maturation. We identified an intraoperative TTF cutoff value that can be used for intraoperative decision-making.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.37 no.4
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• pp.28-34
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• 2000

In this paper, a continuous-time filter for low voltage and high frequency applications using fully-balanced current integrators is presented. As the balanced structure of integrator circuits, the designed filter has improved noise characteristics and wide dynamic range since even-order harmonics are cancelled and the input signal range is doubled. Using complementary current mirrors, bias circuits are simplified and the cutoff frequency of filters can be controlled easily by a single DC bias current. As a design example, the 3rd-order lowpass Butterworth filter with a leapfrog realization is designed. The designed fully-balanced current-mode filter is simulated and examined by SPICE using 0.65${\mu}{\textrm}{m}$ CMOS n-well process parameters. The simulation results show 50MHz cutoff frequency, 69㏈ dynamic range with 1% total harmonic distortion(THD), and 4㎽ power dissipation with a 3V supply voltage.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.1
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• pp.49-58
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• 1999

This paper describes an integrated low pass filter fabricated by using $0.8{\mu}m$ single poly CMOS ASIC technology. The filter has been designed for a 5th-order elliptic switched capacitor filter with cutoff frequency of 5khz, 0.1dB passband ripple. The filter consists of MOS swiches poly capacitors and five CMOS op-amps. For the realization of the SC filter, continuous time transfer function H(s) is obtained from LC passive type, and transfered as discrete time transfer H(z) through bilinear-z transform. Another filter has been designed by capacitor scaling for reduced chip area, considering dynamic range of the op-amp. The test results of two fabricated filters are cutoff frequency of 4.96~4.98khz, 35~38dB gain attenuation and 0.72~0.81dB passband ripple with the ${\pm}2.5V$power supply clock of 50KHz.

• Journal of Intelligence and Information Systems
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• v.12 no.4
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• pp.109-126
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• 2006

An effective customer classification has been essential for the successful customer relationship management. The typical customer rating is carried out by the proportionally allocating the customers into classes in terms of their life time values. However, since this method does not accurately reflect the homogeneity within a class along with the heterogeneity between classes, there would be many problems incurred due to the misclassification. This paper suggests a new method of rating customer using Holistic profit technique, and validates the new method using the customer data provided by an insurance company. Holistic profit is one of the methods used for deciding the cutoff score in screening the loan application. By rating customers using the proposed techniques, insurance companies could effectively perform customer relationship management and diverse marketing activities.

• Clinical and Experimental Pediatrics
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• v.46 no.8
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• pp.758-762
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• 2003

Purpose : Our examination was designed to determine the diagnostic properties of the cutoff point for the prediction of bacteremia in febrile children less than 3 years of age. Cutoff point is the value that simultaneously maximizes both sensitivity and specificity. Methods : We conducted a retrospective study of febrile children, less than 3 years of age, who clinically have no identifiable source of fever. Peripheral blood leukocyte count(WBC), absolute neutrophil count(ANC), erythrocyte sedimentation rate(ESR) and C-reactive protein(CRP) were measured at the same time. All patients received blood culture, urine culture and/or CSF culture. Bacterial infection was defined as single pathogen isolated from the CSF or blood or a urinary tract infection (UTI). Patients were dichotomized into two groups : those with bacterial infection and no bacterial infection. We analyzed the characteristics of the children in the two groups. Results : Seventy-one patients(44 males; 27 females) were enrolled in the study. Twenty patients (28%) had a serious bacterial infection(twelve urinary tract infection, five bacteremia, three meningitis) and fifty-one(72%) had no serious bacterial infection. WBC, ESR and CRP were significantly different between the two groups(P<0.05). The cutoff point of WBC, ESR and CRP were $20,000/mm^3$, 30 mm/hr and 3.0 mg/dL, respectively. The sensitivity and specificity of each cutoff point were WBC(75%, 75%), ESR(79%, 68%) and CRP(83%, 77%), respectively. Conclusion : These data show the ability of predictors to identify febrile children less than 3 years of age with bacterial infection. Febrile children who reach the cutoff point must be treated intensively and those who do not reach the cutoff point can be carefully managed without administering antimicrobial agents.

• The Korean Journal of Nuclear Medicine
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• v.29 no.1
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• pp.41-47
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• 1995

Tc-99m-MIBI(Sestamibi) myocardial SPECT along with T1-201 tomographic imaging has demonstrated wide application and high image qualify sufficient for the diagnosis of myocardial perfusion defect, which consequently reflects regional myocardial blood flow, The qualitative values of myocardial SPECT with Tc-99m-MIBI as well as the quantitative cases depend in some degree on the reconstruction techniques of multiple projections. Filtered backprojection(FBP) is the common standard for reconstruction rather than the complicated and time-consuming arithmetic methods. In FBP it Is known that the distribution of radioactivity in reconstructed transverse slices varies with the selected filter parameters such as cutoff frequencies and order(Butterworth case). The cutoff frequencies basically remove and decrease the true radioactive distribution and alter the pixel counts, which lead to underestimation of true counts in specific myocardial regions. In this study, we have investigated the effect of cutoff frequencies of reconstruction filter on the artifactually induced perfusion defects, which are often demonstrated near inferior and/or inferoseptal cardiac walls due to the intense hepatic uptake of Tc-99m-MIBI. A computerized method for identifying the relative degree of artifactual perfusion defect and for comparing those degrees along with the relative amount of hepatic uptake to myocardium was developed and patient images were studied to observe the quantitative degree of underestimation of myocardial perfusion, and to propose some reasonable thresh-old of cutoff frequency in the diagnosis of perfusion defect quantitatively. We concluded that from the quantitative viewpoint cutoff frequencies may be used as high as possible with the sacrifice of homogeneity of image quality, and those frequencies lower than the common 0.3 Nyquist frequency would reveal severe degradation of radio-active distribution near inferior and/or Inferoseptal myocardium when applying Butterworth or low pass filter.