• Childhood Kidney Diseases
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• v.3 no.1
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• pp.1-10
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• 1999

Purpose: Up to date there is no nationwide survey on epidemiological or clinical data of nephrotic syndrome, so we investigated about age of onset, sex, result of renal biopsy, treatment method, its results of treatment, its responsiveness, time of response to treatment and pattern of relapse in Korea. Methods: Between 1987 and 1997, 2193 patients with primary nephrotic syndrome diagnosed at 38 university hospital and general hospital in Korea were included. Of these 1655 were male and 538 were female. Incidence peaked at 1-5 years of age. Results: Results were as follows; 1) Among 2193 cases, male was 1655($75.5\%$), female was 538 cases($24.5\%$) and male to female ratio was about 3:1. Among 1752 patients with MCNS, male was 1338, female was 414 and male to female ratio was about 3.23:1. The most prevalent age group was 1-5 years of age. 2) Renal biopsy was done in 942 cases($43\%$), pathologic findings were as follows; MCNS 646 cases($68.6\%$), FSCS 149 cases($15.8\%$). 3) Regimen of treatment were as follows; prednisolone 1191 cases, Calcort 192 cases, cyclophosphamide 251 cases, cyclosporin A 223 cases, MPD pulse therapy 120 cases.4) Complete response to treatment were noted in 1597 cases($82.2\%$, n=1944). 5) Responsiveness according to result of renal biopsy were significantly different between MCNS and FSGS. Complete response were noted in $86.5\%$ among patients with MCNS, $35.8\%$ in patients with FSGS. 6) Time of response to treatment were noted between 1 and 4 weeks after treatment in 879 cases($67.4\%$, n=1305). 7) 994 cases($73.1\%$) relapsed during follow up, most frequently between 2 months and 6 months after response. Conclusion : Nationwide survey of epidemiological and clinical data were performed in childhood primary nephrotic syndrome. Most of the clinical and epidemiological data were similar to other reports from U.S.A. and from Europe, however male to female ratio is higher in Korean nephrotic syndrome(3:1 in contrast to 2:1).

• Childhood Kidney Diseases
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• v.2 no.2
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• pp.183-186
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• 1998

Steroid Resistant Nephrotic Syndrome(SRNS) in children has poor prognosis and no effective therapy. In 1994, Ravi Elhence have reported that IV cyclophosphamide therapy was effective against SRNS of children. So, we evaluated the efficacy of IV cyclophosphamide in 3 children with biopsy proven steroid-resistant MCNS. And the result was the rapeutic failure. In conclusion, IV cyclophosphamide therapy wass not effective against SRNS of children.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.2C
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• pp.150-159
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• 2002

This paper presents the convergence time, SER(Symbol Error Rate), MSE(Mean Square Error), hardware complexity and step-size(${\mu}$) about various LMS(Least Mean Square) algorithms in FS-DFE(Fractionally Spaced-Decision Feedback Equalize) for Cable Modem based on MCNS(Multimedia Cable Network System) DOCSIS(Data Over Cable Service Interface Specification) v1.0/v1.1 standards. We designed and simulated using ${SPW}^{TM}$ and synthesized using STD90 library through ${SYNOPSYS}^{TM}$. And also, we adopted the time-multiplexed multiplication and tap shared architecture in order to achieve the low hardware complexity. Simulation results show that DS-LMS algorithms[1][3] is the optimum solution about performace and hardware size. in high order QAM applications. Finally, we achieved area saving about 58% using DS-LMS algorithm compare with conventional equalizer architecture.

• Information and Communications Magazine
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• v.15 no.7
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• pp.75-94
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• 1998

In this paper, HFC CATV networks are introduced. HFC CATV networks are currently considered as a most effective and plausible solution for subscriber access networks in the information superhighway, among others such as ADSL and B-WLL. The advantages of HFC CATV networks include its broad upstream and downstream channel bandwidths, much wider than PSTN's and its readiness. The HFC CATV networks are already well spread among the general subscribers in Korea. This fact will shorten the installation period and significantly reduce its cost. In addition, The structure and channel environment of the HFC CATV networks are introduced. At the same time, in this paper included are major problems in the HFC CATV networks and the solutions for these problems. Also discussed are data transmission, medium access control, IEEE802.14, and MCNS for standardizations. Moreover, additional telecommunications service activities in both Korea and other countries, using HFC CATV networks are also included. The topics which are covered in detail are the ones such as interoperation between HFC CATV networks and trunk line and the digital transmission performance test for the CATV networks. In the performance test, it is concluded that HFC CATV networks can satisfy the QoS for various additional services if the number of the subscribers in a cell is limited to less than 500 and other minor requirements are satisfied. Based on all these discussions and conclusions, HFC CATV networks are suggested in this paper for the subscriber access networks of the so called information superhighway.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.9A
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• pp.1332-1339
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• 2000

This paper presents the architecture and design of a high speed asymmetric data transmission baseband MODEM ASIC chip for CATV networks. The implemented MODEM chip supports the physical layer of the DOCSIS(Data Over Cable Service Interface Specification) standard in MCNS(Multimedia Cable Network System) The chip consists of a QPSK/16-QAM transmitter and a 64/256-QAM receiver which contain a symbol timing recovery circuit, a carrier recovery circuit, a blind equalizer using MMA and LMS algorithms. The chip can support data rates of 64Mbps at 256 QAM and 48Mbps at 64-QAM and can provide symbol rates up to 8MBaud. This symbol rate is faster than existing QAM receivers. We have performed logic synthesis using the $0.35\mu\textrm{m}$ standard cell library. The total number of gates is about 290,000 and the implemented chip is being fabricated and will be delivered soon.

• Journal of Communications and Networks
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• v.8 no.4
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• pp.432-441
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• 2006

As the community antenna television (CATV) networks becomes ubiquitous, instead of constructing an entirely new broadband network infrastructure, it has emerged as one of the rapid and economic technologies to interconnecting heterogeneous network to provide broadband access to subscribers. How to support ubiquitous real-time multimedia applications, especially in a heavy traffic environment, becomes a critical issue in modern CATV networks. In this paper, we propose a time guaranteed and efficient upstream minislots allocation algorithm for supporting quality-of-service (QoS) traffic over data over cable service interface specification (DOCSIS) CATV networks to fulfill the needs of realtime interactive services, such as video telephony, video on demand (VOD), distance learning, and so on. The proposed adaptive fast expansion algorithm and the loading statistics with dynamic swapping algorithm have been shown to perform better than that of the multimedia cable network system (MCNS) DOCSIS.

• Electronics and Telecommunications Trends
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• v.11 no.4 s.42
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• pp.63-75
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• 1996

본 고에서는 일반 가정 및 소규모 업무용 가입자들에 대한 광대역화의 가장 경제적인 대안으로 관심을 끌고 있는 Hybrid fiber-coax 구조의 CATV 전송망에 대한 표준화 동향에 대해 조사 분석한 내용을 기술한다. HFC 액세스망에 대한 표준화는 IEEE 802.14 그룹, DAVIC, ATM Forum, IETF(Internet Engineering Task Force)와 Cable TV업계 등 여러기구에서 추진하고 있다. 지금까지 물리계층, MAC계층 등에 대한 주요 표준규격에 대해 DAVIC과 IEEE 802.14에서 주도하고 있으나, 앞으로는 데이터 서비스에 상대적 우선 순위를 두고 표준화를 추진하는 IEEE 802.14그룹에서 주도하게 될 것으로 보인다. 또한 인터넷 접속과 고속 데이터 서비스를 위한 인터페이스와 IP 접속 프로토콜에 대한 표준화를 발 빠르게 추진하고 있는 IETF와 MCNS(Multimedia Cable Network System) 등의 역할이 커질 것으로 전망된다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.1
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• pp.147-161
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• 2012

In recent years, machine-to-machine (M2M) communications are under rapid development to meet the fast-increasing requirements of multi-type wireless services and applications. In order to satisfy M2M communications requirements, heterogeneous networks convergence appears in many areas, i.e., mobile cellular networks (MCNs) and wireless sensor networks (WSNs) are evolving from heterogeneous to converged. In this paper, we introduce the system architecture and application requirement for converged MCN and WSN, where mobile terminals in MCN are acting as both sensor nodes and gateways for WSN. And then, we discuss the joint optimization of converged networks for M2M communications. Finally, we discuss the technical challenges in the converged process of MCN and WSN.

• Childhood Kidney Diseases
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• v.23 no.1
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• pp.1-6
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• 2019

Nephrotic syndrome (NS) is the most common glomerular disorder in childhood, and a vast majority of cases are idiopathic. The precise cause of this common childhood disease is not fully elucidated despite significant advancements in our understanding of podocyte biology. Idiopathic NS has been considered "a disorder of T-cell function" mediated by a circulating factor that alters podocyte function resulting in massive proteinuria since the last four decades. Several circulatory factors released from T-cells are considered to be involved in pathophysiology of NS; however, a single presumptive factor has not been defined yet. Extended evidence obtained by advances in the pathobiology of podocytes has implicated podocytes as critical regulator of glomerular protein filtration and podocytopathy. The candidate molecules as pathological mediators of steroid-dependent NS are CD80 (also known as B7-1), hemopexin, and angiopoietin-like 4. The "two-hit" hypothesis proposes that the expression of CD80 on podocytes and ineffective inhibition of podocyte CD80 due to regulatory T-cell dysfunction or impaired autoregulation by podocytes results in NS. Recent studies suggest that not only T cells but also other immune cells and podocytes are involved in the pathogenesis of MCNS.

• Childhood Kidney Diseases
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• v.5 no.2
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• pp.100-108
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• 2001

Purpose : We investigated the incidence and predisposing factors of pulmonary embolism in minimal change nephrotic syndrome(MCNS). Methods : Lung perfusion scan using 99mTC-MAA were done on 14 patients who were diagnosed to minimal change nephrotic syndrome. Group h: Five patients who had perfusion defects on scan, Group B; Nine patients who had no perfusion defect on scan. Between the two groups, the differences of platelet number, hematocrits, albumin, cholesterol, triglyceride, proteinuria were evaluated. Results : Five patients were found to have perfusion defect consistent with pulmonary embolism($35.7\%$). However, there were minimal or no respiratory symptoms and signs. In our laboratory studies, the mean proteinuria on admissions was $676{\pm}31\;mg/m2/hr$ in the group with pulmonary embolism, and $313{\pm}28\;mg/m2/hr$ in the group without pulmonary embolism. There were more severe proteinuria in group with pulmonary embolism(P<0.05). The mean platelet count at early stage of remission after steroid treatment was $746,600{\pm}280,000/mm3$ in the group with pulmonary embolism, $511,890{\pm}90,000/mm3$ in the group without pulmonary embolism. There were significant difference of platelet count between the two groups(P<0.01). In patients with pulmonary embolism, there were more higher and sustained increasement of platelet count. All cases of pulmonary embolism were treated with dipyridamole(5 mg/kg). In 4 cases the perfusion defects were improved in two weeks, however, one case showed persistent perfusion defect after 1 month. Conclusion : Our study suggested that pulmonry embolism might be one of tile major complications in childhood MCNS The occurrence rate was correlated with severity of proteinuria before treatment and sustained increasement of platelet counts in early remission state after steroid treatment. Therefore, the scintigraphic pulmonary perfusion study is mandatory in childhood MCNS, especially in the high risk patients, such as the patients with severe proteinuria and sustained increasement of platelet count. (J Korean Soc Pediatr Nephrol 2001;5 : 100-8)