• BMB Reports
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• 제50권3호
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• pp.138-143
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• 2017

Ovariectomy-induced bone loss is related to an increased deposition of osteoclasts on bone surfaces. We reported that the 36-amino-acid-long neuropeptide Y (NPY) could mobilize hematopoietic stem/progenitor cells (HSPCs) from the bone marrow to the peripheral blood by regulating HSPC maintenance factors and that mobilization of HSPCs ameliorated low bone density in an ovariectomy-induced osteoporosis mouse model by reducing the number of osteoclasts. Here, we demonstrated that new NPY peptides, recombined from the cleavage of the full-length NPY, showed better functionality for HSPC mobilization than the full-length peptide. These recombinant peptides mediated HSPC mobilization with greater efficiency by decreasing HSPC maintenance factors. Furthermore, treatment with these peptides reduced the number of osteoclasts and relieved ovariectomy-induced bone loss in mice more effectively than treatment with full-length NPY. Therefore, these results suggest that peptides recombined from full-length NPY can be used to treat osteoporosis.

• 한국통신학회논문지
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• 제24권9A호
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• pp.1306-1313
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• 1999

본 논문은 CDMA PCS 이동통신 시스템의 망 설계를 위하여 거리에 따른 신호 감쇄 현상 분석 모델(변형된 Hata path loss model) 및 통계적 신호 강도 분포 모델(Log-Normal 분포)을 제시한다. 제시된 모델에 대구 산적동 및 수성동 지역의 측정 데이터를 적용하여 이들 지역에서 신호 강도의 세기가 임계치를 초과하는 지역의 백분율을 산출하여 망 설계의 기본 자료로 활용할 수 있도록 하였다.

• 정보처리학회논문지B
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• 제9B권2호
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• pp.173-180
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• 2002

기존의 VOB(Virtual Output Buffer) 모델에서 신경회로망의 학습 패턴 처리를 위해 가상 셀 손실율이 도입되었다. VOB모델은 신경망이 실제 셀 손실율 없이도 연결 수락 경계을 잘 찾을 수 있음을 보여주었다. 그러나 VOB 모델은 셀 손실율을 과다 평가하는 경향이 있어 결과적으로 망 자원의 이용률이 낮은 단점이 있다. 본 논문에서는 이러한 단점을 보완하는 방법으로 연결 수락 경계에서 셀 손실율의 평균에 대한 정보를 충분히 포함하는 셀 손실율 참조 곡선의 개념을 제안하였다. 그리고 제안된 셀 손실율 참조 곡선을 이용하여 가상 셀 손실율을 처리하는 방법을 제안하였다. 제안된 한습 패턴 처리 방법은 ATM 트래픽 중에 가장 대표적인 두 가지 호원에 대하여 실험하였다. 실험에 사용된 호원은 LAN 데이터의 그래픽 특성을 가시는 On-Off 트래픽과 비디오 화상 통신의 특성을 가지는 Auto-Regressive 트래픽이다.

• 전기전자학회논문지
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• 제3권1호
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• pp.22-28
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• 1999

기존의 CREG-VP는 VP상에서 FEC기법을 사용하여 트래픽 과잉으로 인한 연속적인 셀 손실을 보상하는 기법으로써, 평균 코딩/디코딩 시간이 짧고, ATM 표준 셀 형식과 호환성을 유지할 수 있다는 장점을 지니고 있으나, 복구할 수 있는 셀의 수에는 제한이 존재한다. 본 논문에서는 CREG-VP를 확장하여 버스트 특성을 갖는 트래픽에서도 효과적으로 셀 손실을 복구하는 기법을 제안하였다. 제안된 기법은 CRP를 변경하여 셀 손실의 검출 성능을 향상시켰고, 인터리브 패리티 셀을 적용하여 연속적인 셀의 복구성능을 향상시켰다. 실험 결과 제안된 기법은 CREG-VP 방식보다 셀 손실률 감소 계수를 향상 시킴을 알 수 있었다.

• ETRI Journal
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• 제20권3호
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• pp.251-271
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• 1998

It is well known that if usage parameter control/network parameter control (UPC/NPC) functions are used together with a cell loss priority control scheme in ATM networks, the measurement phasing problem can occur. This makes it difficult for a network provider to define and commit the cell loss ratio as a QoS parameter. To solve the problem, we propose a new UPC/NPC algorithm. By using the proposed UPC/NPC algorithm, we can define the cell loss ratios for CLP = 0 and CLP = 0+1 cell streams without the measurement phasing problem under any conditions. We analyzed the performance of the proposed UPC/NPC algorithm. Using a discrete time model for the UPC/NPC architecture with a discrete-time semi-Markov process (DSMP) input model, we obtained the cell discarding probabilities of CLP = 0 and CLP = 0+1 cells streams and showed that more CLP = 0 cells are accepted compared to what was proposed in ITU-T.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제12B권1호
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• pp.37-43
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• 2002

This paper proposes a new zero-current switching (ZCS) pulse-width modulation (PWM) switch cell that has no additional conduction loss of the main switch. In this cell, the main switch and the auxiliary switch turn on and turn off under zero current condition. The diodes commutate softly and the reverse recovery problems are alleviated. The conduction loss and the current stress of the main switch are minimized, since the resonating current for the soft switching does not flow through the main switch. Based on the proposed ZCS PWM switch cell, a new family of dc to dc PWM converters is derived. The new family of ZCS PWM converters is suitable for the high power applications employing IGBTs. Among the new family of dc to dc PWM converters, a boost converter was taken as an example and has been analyzed. Design guidelines with a design example are described and verified by experimental results from the 2.5㎾ prototype boost converter operating at 40KHz.

• 한국정보처리학회논문지
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• 제6권10호
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• pp.2779-2789
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• 1999

In this paper, we propose a new neural Buffered Leaky Bucket algorithm for preventing the degradation of network performance caused by congestion and dealing with the traffic congestion in ATM networks. We networks. We justify the validity of the suggested method through performance comparison in aspects of cell loss rate and mean transfer delay under a variety of traffic conditions requiring the different QoS(Quality of Service). also, the cell scheduling algorithms such as DWRR and DWEDF used for multiplexing the incoming traffics are induced to get the delay time of the traffics fairly. The network congestion information from cell scheduler is used to control the predicted traffic loss rate of Neural Leaky Bucket, and token generation rate is changed by the predicted values. The prediction of traffic loss rate by neural networks can effectively reduce the cell loss rate and the cell transfer delay of next incoming cells and be applied to other traffic control systems. Computer simulation results performed for traffic prediction show that QoSs of the various kinds of traffics are increased.

• Tuberculosis and Respiratory Diseases
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• 제73권1호
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• pp.11-21
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• 2012

Background: While qualitative analysis of methylation has been reviewed, the quantitative analysis of methylation has rarely been studied. We evaluated the methylation status of CDKN2A, $RAR{\beta}$, and RASSF1A promoter regions in non-small cell lung carcinomas (NSCLCs) by using pyrosequencing. Then, we evaluated the association between methylation at the promoter regions of these tumor suppressor genes and the clinicopathological parameters of the NSCLCs. Methods: We collected tumor tissues from a total of 53 patients with NSCLCs and analyzed the methylation level of the CDKN2A, $RAR{\beta}$, and RASSF1A promoter regions by using pyrosequencing. In addition, we investigated the correlation between the hypermethylation of CDKN2A and the loss of $p16^{INK4A}$ immunoexpression. Results: Hypermethylation of CDKN2A, $RAR{\beta}$, and RASSF1A promoter regions were 16 (30.2%), 22 (41.5%), and 21 tumors (39.6%), respectively. The incidence of hypermethylation at the CDKN2A promoter in the tumors was higher in undifferentiated large cell carcinomas than in other subtypes (p=0.002). Hyperrmethylation of CDKN2A was significantly associated with $p16^{INK4A}$ immunoexpression loss (p=0.045). With regard to the clinicopathological characteristics of NSCLC, certain histopathological subtypes were found to be strongly associated with the loss of $p16^{INK4A}$ immunoexpression (p=0.016). Squamous cell carcinoma and undifferentiated large cell carcinoma showed $p16^{INK4A}$ immunoexpression loss more frequently. The Kaplan-Meier survival curves analysis showed that methylation level and patient survival were barely related to one another. Conclusion: We quantitatively analyzed the promoter methylation status by using pyrosequencing. We showed a significant correlation between CDKN2A hypermethylation and $p16^{INK4A}$ immunoexpression loss.

• 한국컴퓨터정보학회논문지
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• 제5권4호
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• pp.82-89
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• 2000

본 논문은 실시간과 비실시간 버스트 트래픽을 가진 ATM 멀티플렉서의 셀 손실율을 분석하였다. 분석을 위하여 손실 우선순위 제어를 가진 ATM 멀티플렉서를 가정하였으며, 손실 우선순위 제어는 셀 헤더의 CLP필드를 이용하였다. 분석을 쉽게 하고 계산을 간략히 하기 위하여, ATM멀티플렉서의 다중화된 트래픽은 MMDP로 모델링하였다. ATM 멀티플렉서는 MMDP/MMDP/l/K 큐잉 모델로 시뮬레이션하였다. 분석결과, 손실우선순위 제어를 가진 ATM 멀티플렉서의 연결 수락은 낮은 우선순위를 갖는 셀손실율에 의하여 결정될 뿐만 아니라, 한계 버퍼의 크기에 의해서 결정된다는 결론을 얻었다. 따라서, ATM 멀티플렉서는 통계적 다중화 이득을 증가하기 위해서 손실 우선순위 제어를 이용하는 것이 유리함을 알 수 있었다.

• 한국수소및신에너지학회논문집
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• 제16권2호
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• pp.170-179
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• 2005

Electrolyte loss is considered as one of the major obstacles limiting the life time of molten carbonate fuel cells (MCFCs). Unit cells with an effective area of 100 $cm^2$ were prepared and were operated to determine the optimum matrix thickness which contains the maximum amount of electrolyte without serious preformance loss caused by high resistance. Matrices with different thickness, 1.45, 1.8, and 2.3 mm, were used in unit cells and those cells were operared about 5000, 10000, and 4000 hrs. The unit cell used 1.8 mm thick matrix showed 0.85 V (at 150 mA/$cm^2$) as the intial performance and this cell voltage is not lower than the cell voltage obtained in the cell with 1 mm thick matrix. This cell was operated for 10000 hrs. The cell used 1.45 mm thick matrices showed 16.6 % in the electrolyte loss after 5000 hr operation. In the case of the cell with 2.3 mm thick matrix, the initial cell voltage was below 0.80 V (at 150 mA/$cm^2$). For thermal cycle test, the gas crossover amount of unit cell used 1.8 mm thick matrix was much less than that of the cell with 1.0 mm thick matrix.