• Korean Journal of Clinical Laboratory Science
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• v.49 no.3
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• pp.203-213
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• 2017

Serum creatinine-based eGFR and serum cystatin C-based eGFR are the most popular methods for measuring renal function. Thyroid hormone is known to affect serum creatinine-based eGFR and serum cystatin C-based eGFR; however, the clinical significance of thyroid dysfunctional patients of renal function evaluation has not been fully elucidated to date. This study examined the effect of thyroid hormone on serum creatinine-based eGFR and serum cystatin C-based eGFR. Moreover, we also evaluated the correlation analysis between serum creatinine-based eGFR and serum cystatin C-based eGFR in patients with thyroid dysfunction. A total of 442 patients with hypothyroidism and 284 patients with hyperthyroidism were investigated. A correlation analysis between thyroid hormone and serum creatinine- (and cystatin C-) based eGFR was performed. A correlation analysis between thyroid hormone and serum cystatin-C based eGFR indicated that serum cystatin-C based eGFR is more of an independent biomarker than serum creatinine-based eGFR in thyroid dysfunction patients. Therefore, serum cystatin C-based eGFR more accurately reflects renal function than serum creatinine-based eGFR in thyroid dysfunction patients.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.1
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• pp.73-82
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• 2004

As a new service category to better support TCP traffic in ATM networks, the Guaranteed Frame Rate (GFR) service category aims to support minimum cell rate guarantee, fairly distribute available bandwidth while keeping the simplicity of Unspecified Bit Rate (UBR). In this paper, we proposed a buffer management scheme which uses the per-VC accounting of single FWO queue and capable of supporting both GFR.1 and GFR.2 conformance definition. The proposed buffer management deal with GFR.1 and GFR.2 conformance definitions differentially by controlling the number of CLP=0 cell and CLP=1 cell which are occupying buffer space. The simulation results show that our proposed scheme satisfies the requirements of GFR services as well as improves total fairness index and each conformance definition fairness index.

• Journal of Korea Society of Industrial Information Systems
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• v.10 no.1
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• pp.49-57
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• 2005

ATM Form has defined the guaranteed frame rate (GFR) service to provide minimum cell rate (MCR) guarantees for TCP traffic in ATM networks and allow it to fairly share residual bandwidth. GFR switch implementation consists of the frame-based generic cell rate algorithm (F-GCRA) and a frame forwarding mechanism. The F-GCRA identifies frames that are eligible for an MCR guarantee. The frame forwarding mechanism buffers cells at a frame unit according to information provided by the F-GCRA and forwards the buffered cells to an output port according to its scheduling discipline. A simple GFR mechanism with shared buffer with a global threshold is a feasible implementation mechanism, but has been known that it is insufficient to guarantee the MCR. This paper has estimated performance of GFR service for TCP traffic over ATM switches with the simple FIFO-based mechanism

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.12
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• pp.520-528
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• 2002

The ATM Forum recently introduced the Guaranteed Frame Rate(GFR) service category GFR service has been designed to support classical best effort traffic such as TCP/IP based traffic. The GFR service not only guarantees a minimum throughput, but also supports fair distribution of available bandwidth to completing VCs. In this paper, we proposed a new buffer management algorithm based on leaky bucket to provide minimum cell rate guarantee and improve fairness. The proposed algorithm reduces complexity and processing overhead of leaky-bucket algorithm to implement easily.

• Korean Journal of Clinical Laboratory Science
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• v.53 no.1
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• pp.32-40
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• 2021

This study examined the association between hypertension (HTN), estimated glomerular filtration rate (eGFR), and urine microalbumin/creatinine ratio (ACR) in Korean adults. Data for 8,922 adults (3,941 men and 4,981 women) aged ≥20 years from the Sixth Korean National Health and Nutrition Examination Survey VI (2013~2014) were analyzed. In men, after adjusting for the related variables, the odds ratios (ORs) of HTN [systolic blood pressure (SBP) ≥140 mmHg, diastolic blood pressure (DBP) ≥90 mmHg, or use of HTN medications] were significantly higher in the decreased eGFR group [eGFR <60 mL/min/1.73 ㎡, 1.98 (95% CI, 1.21~3.24)], elevated ACR group [ACR ≥30 mg/g, 2.03 (95% CI, 1.54~2.69)], and decreased eGFR plus elevated ACR group [eGFR <60 mL/min/1.73 ㎡ and ACR ≥30 mg/g, 6.03 (95% CI, 2.82~12.92)] than in the normal group (eGFR ≥60 mL/min/1.73 ㎡ and ACR <30 mg/g). In women, after adjusting for the related variables, the ORs of HTN were significantly higher in the decreased eGFR group (2.29, 95% CI, 1.27~4.13), elevated ACR group (2.22, 95% CI, 1.68~2.94), and decreased eGFR plus elevated ACR group (10.77, 95% CI, 3.89~29.82) than the normal group. In conclusion, HTN was associated with a decreased eGFR and elevated ACR in Korean men and women. In addition, the prevalence of HTN increased greatly when a decreased eGFR and elevated ACR occurred simultaneously.

• The Korean Journal of Nuclear Medicine Technology
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• v.23 no.2
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• pp.25-28
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• 2019

Purpose In patients with unusual kidney position after $^{99m}Tc-DTPA$ renal dynamic imaging study, the GFR(Glomerular Filtration Rate) values are significantly different according to the depth of the kidney. Thus, we tried to compare the difference of the GFR values between the depth measurement methods and in-vitro test. 30 adult patients who were subjected to renal study. 27 patients were in usual position and 3 patients were in unusual. $555{\pm}37MBq$ of $^{99m}Tc-DTPA$ was administrated to all patients. GE infinia gamma camera was used. GFR values were obtained in-vivo(gates method) and in-vitro(blood). The kidney depth in-vivo was calculated by three methods(tonnensen, manual, taylor). In-vitro, GFR was performed by blood test. Differences in the mean values of GFR and correlation between depth and GFR values were evaluated using the SPSS 12.0 statistical program. The GFR values for 27 patients with kidney in the usual position are as follows(1.tonnensen 2.manual 3.taylor 4.invitro); $69.3{\pm}4.2$, $88.2{\pm}5.6$, $77.8{\pm}4.3$, $82.2{\pm}5.8ml/min$. The three unusual cases are as follows, first(congenital renal anomaly): 66.4, 101.24, 69.07, 94.8 ml/min. second(transplantation kidney): 12.22, 29.99, 19.36, 23.5 ml/min. third(horseshoe kidney): 37.37, 93.54, 35.9, 92.5 ml/min. There was a difference between tonnensen and manual in the usual position of the kidney(p<0.05). There was no significant difference between the other methods. However, there was a significant difference in case of the unusual position of the kidneys. Correlation analysis between both kidney depth and GFR value shows person correlation as follows; Rt kidney: 0.298, Lt kidney: 0.322. When compared with the GFR values in-vitro test, it was useful to calculate the GFR value by measuring the kidney depth using a manual formula in the unusual position of the kidneys. GFR values and kidney depth were significantly related.

• The KIPS Transactions:PartC
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• v.10C no.3
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• pp.305-310
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• 2003

The performance of various GFR implementations has been recently studied due to the interest to provide bandwidth guarantees with a simpler implementation than ABR in ATM networks. One of the important factors is buffer management for guaranteeing QoS in GFR service. An efficient buffer management algorithm is necessary to guarantee MCR for untagged cell in ATM switch. In this paper, we propose and evaluate a buffer management scheme to provide the GFR service guarantees. The proposed scheme can control the cell discarding for fairness in each VC, and compared with Double-EPD and DFBA. Our results show that the proposed buffer management with per-VC queuing achieves significant enhancement on goodputs and fairness index than those of existing methods.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.7
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• pp.22-29
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• 2002

The Gauranteed Frame Rate service category was proposed by the ATM Forum as an enhancement to the UBR service. This service aims to support minimum cell rate gaurantee for each virtual connection and allow any excess bandwidth in the network to be shared among the contending VCs in a fair manner. We propose a new buffer management algorithm for GFR service through FIFO queuing discipline. Proposed scheme can provide minimum bandwidth guarantee for GFR VCs as well as improve the fairness among the competing GFR VCs on a single FIFO queue. From simulation results, we demonstrate the proposed scheme fulfills the requirement of GFR service as well as improves the TCP throughput.

• The Journal of the Korea Contents Association
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• v.7 no.12
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• pp.238-244
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• 2007

Guaranteed Frame Rate(GFR), recently approved by the ATM Forum, expects to become an important service category to efficiently support TCP/IP traffic in ATM networks. The GFR service not only guarantees a minimum service rate at the frame level, but also supports a fair share of available bandwidth. We proposed new scheduling scheme for the GFR service. Proposed scheme provides priority to VCs and high priority to a VC which have more untagged cells in buffer. High priority VCs have much more serviced than low priority. Proposed scheme can provide MCR(minimum cell rate) guarantee and fair sharing to GFR VCs. Computer simulation results show that proposed scheduling scheme provide a much better performance in TCP goodput and fairness than previous scheme.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.9
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• pp.12-19
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• 2002

Guaranteed Frame Rate(GFR) service is intended to efficiently support TCP/IP traffic in ATM networks. The GFR service not only guarantees a minimum service rate at the frame level, but also supports a fair share of available bandwidth. The original GFR proposal outlined two switch implementation scheme : FIFO Queuing and perVC-Queuing. In general, it has been shown that FIFO Queuing is not sufficient to provide rate guarantees and perVC-Queuing with scheduling is needed. In perVC-Queuing implementation, scheduling algorithm plays key rule to provide rate guarantees and to improve fairness. We proposed a new scheduling algorithm for the GFR service. Proposed algorithm can provide minimum service rate guarantee and fair sharing to GFR VCs. Computer simulation results show that proposed scheduling scheme provide a much better performance in TCP Goodput and fairness than previous scheme.