A Packet Buffer Management for Increasing Performance in WiMedia WLP-based Networks

Seung Beom Lee,Seong Ro Lee 한국정보통신학회 2014 2016 INTERNATIONAL CONFERENCE Vol.6 No.1

Performance of TCP can be severely degraded in WiMedia WLP-based network. Packet loss not related to network congestion occurs frequently during inter-subnetwork handoff by user mobility. To solve this problem, packet buffering method recovers those packets dropped during handoff by forwarding buffered packets at old BS (Bridge Station or Base Station) to mobile nodes. But, when a mobile node moves to a congested BS, those buffered packets are dropped and TCP transmission performance of the mobile node degrades severely. In this paper, we propose a Modified BLUE(MBLUE) buffer to increase TCP throughput. MBLUE buffer mitigates global synchronization problem caused by burst packet drops without additional buffer. Simulation results show that MBLUE buffer increases TCP throughput than a conventional buffer management.

Mutation of plastid ribosomal protein L13 results in an albino seedling-lethal phenotype in rice

이진원,장성회,류상훈,이슬비,박준흠,이시철,Gynheung An,박순기 한국육종학회 2019 Plant Breeding and Biotechnology Vol.7 No.4

Chloroplasts are essential plant organelles that play important roles in photosynthesis and are involved in manyfundamental metabolic pathways. Plastid ribosomal proteins are essential components of protein synthesis machinery and have diverseroles in plant growth and development during chloroplast differentiation. In this study, we isolated and characterized T-DNA-taggedrice mutant (prpl13), which exhibited albino seedling lethality. PRPL13 is a nuclear gene encoding the 50S ribosomal protein L13,which is localized in chloroplasts. Transmission electronic microscopy analysis showed abnormal plastid development in thethylakoids of the chloroplasts of the prpl13 mutant seedlings. Chlorophyll and carotenoid contents were also significantly reduced inthe leaves of the mutants. Quantitative reverse transcription-PCR analysis revealed that the prpl13 mutations altered the expressionlevels of genes involved in photosynthesis and chloroplast development. Thus, our data indicate that nuclear-encoded PRPL13 plays animportant role in chloroplast development in rice.

Workplace Learning and Performance 역량모형 타당도 검증 및 전문분야에 따른 HRD 전문가의 역량 인식

김영길 ( Young Kil Kim ),이기성 ( Ki Sung Lee ) 한국인력개발학회 2010 HRD연구 Vol.12 No.4

본 연구는 국내 HRD 분야 중 기업 외부에서 종사하는 HRD 전문가들의 전문분야에 따라 WLP 역할과 역량의 중요도 및 자신의 숙련도에 대해 어떻게 인식하는지 규명하고자 하였다. 서울·경인권 소재 HRD 전문가를 대상으로 실시한 설문조사 자료를 분석한 결과, 첫째, 2004 ASTD 역량 연구에서 제시한 WLP 역량모형 중 하위 역량군의 범주 구분은 한국 실정에 타당하지 않았다. 둘째, 국내 HRD 전문가가 인식하기에 가장 중요한 WLP 역할은 ``비즈니스 파트너`` 역할이고, 가장 중요한 WLP 역량은 ``효과적 커뮤니케이션``이었다. 둘째, 국내 HRD 전문가의 전문분야에 따른 WLP 역할과 역량의 중요도 인식에는 집단간 유의미한 차이가 없었으나 전문분야에 따른 숙련도 인식은 WLP 역할이 ``학습 전략가``와 ``프로젝트 매니저`` 역할에서 집단간 유의미한 차이가 나타났다. WLP 역량이 열두 가지 역량 중 ``신뢰 구축``과 ``효과적 커뮤니케이션``, 그리고 ``적응력`` 역량을 제외한 아홉 가지 역량 모두 집단간 유의미한 차이가 나타났다. 이상의 연구결과를 토대로 국내 HRD 전문분야에 종사하는 전문가들의 역량강화를 위한 시사점과 연구의 한계점을 제시하였다. The purpose of this study was to analyze the perceptions of HRD professionals in workplace learning and performance(WLP) competencies according to the areas of expertise. Data was collected through questionnaires administered to HRD professionals working in Seoul, Incheon and Kyounggi-Do. The results of the study were as follows. Firstly, the WLP sub-competency clusters that was presented 2004 ASTD competency study was identified as not valid from exploratory factor analysis and confirmatory factor analysis. Secondly, the role of business partner and effective communication competency ranked highest in the level of importance. Thirdly, there were not significant differences in the importance of WLP roles and competencies according to areas of expertise, but there were significant differences in the proficiencies of learning strategist and project manager between consulting group to trainer group. and there were significant differences in the proficiencies of competencies according to areas of expertise besides building trust, communicating effectively, and demonstrating adaptability. And the implications of the results, limitations of this study were also suggested.

한국과 글로벌 HRD 전문가의 WLP 역량 인식 비교연구

김영길,길민욱 한국디지털정책학회 2012 디지털융복합연구 Vol.10 No.6

FO-WLP(Fan Out-Wafer Level Package) 차세대 반도체 Packaging용 Isocyanurate Type Epoxy Resin System의 경화특성연구

김환건 한국반도체디스플레이기술학회 2019 반도체디스플레이기술학회지 Vol.18 No.1

The cure properties of ethoxysilyl diglycidyl isocyanurate (Ethoxysilyl-DGIC) and ethylsilyl diglycidyl isocyanurate(Ethylsilyl-DGIC) epoxy resin systems with a phenol novolac hardener were investigated for anticipating fan out-wafer level package(FO-WLP) applications, comparing with ethoxysilyl diglycidyl ether of bisphenol-A(Ethoxysilyl-DGEBA) epoxy resin systems. The cure kinetics of these systems were analyzed by differential scanning calorimetry with an isothermal approach, and the kinetic parameters of all systems were reported in generalized kinetic equations with diffusion effects. The isocyanurate type epoxy resin systems represented the higher cure conversion rates comparing with bisphenol-A type epoxy resin systems. The Ethoxysilyl-DGIC epoxy resin system showed the highest cure conversion rates than Ethylsilyl-DGIC and Ethoxysilyl-DGEBA epoxy resin systems. It can be figured out by kinetic parameter analysis that the highest conversion rates of Ethoxysilyl-DGIC epoxy resin system are caused by higher collision frequency factor. However, the cure conversion rate increases of the Ethylsilyl-DGEBA comparing with Ethoxysilyl-DGEBA are due to the lower activation energy of Ethylsilyl-DGIC. These higher cure conversion rates in the isocyanurate type epoxy resin systems could be explained by the improvements of reaction molecule movements according to the compact structure of isocyanurate epoxy resin.

WLP(Wafer Level Package)적용을 위한 SEMC(Sheet Epoxy Molding Compounds)용 Naphthalene Type Epoxy 수지의 경화특성연구

김환건,Kim, Whan Gun 한국반도체디스플레이기술학회 2020 반도체디스플레이기술학회지 Vol.19 No.1

The cure characteristics of three kinds of naphthalene type epoxy resins(NET-OH, NET-MA, NET-Epoxy) with a 2-methyl imidazole(2MI) catalyst were investigated for preparing sheet epoxy molding compound(SEMC) for wafer level package(WLP) applications, comparing with diglycidyl ether of bisphenol-A(DGEBA) and 1,6-naphthalenediol diglycidyl ether(NE-16) epoxy resin. The cure kinetics of these systems were analyzed by differential scanning calorimetry with an isothermal approach, and the kinetic parameters of all systems were reported in generalized kinetic equations with diffusion effects. The NET-OH epoxy resin represented an n-th order cure mechanism as like NE-16 and DGEBA epoxy resins, however, the NET-MA and NET-Epoxy resins showed an autocatalytic cure mechanism. The NET-OH and NET-Epoxy resins showed higher cure conversion rates than DGEBA and NE-16 epoxy resins, however, the lowest cure conversion rates can be seen in the NET-MA epoxy resin. Although the NETEpoxy and NET-MA epoxy resins represented higher cure reaction conversions comparing with DGEBA and NE-16 resins, the NET-OH showed the lowest cure reaction conversions. It can be figured out by kinetic parameter analysis that the lowest cure conversion rates of the NET-MA epoxy resin are caused by lower collision frequency factor, and the lowest cure reaction conversions of the NET-OH are due to the earlier network structures formation according to lowest critical cure conversion.

상수원 보호를 위한 유역기반 토지관리 우선순위 모델 적용

이지현 ( Jee Hyun Lee ),최지용 ( Ji Yong Choi ),박석순 ( Seok Soon Park ) 한국물환경학회 2004 한국물환경학회지 Vol.20 No.5

Due to the growing impact of non-point source pollution and limitation of water treatment technology, a new policy of water quality management, called a source protection, is now becoming more important in drinking water supply. The source protection means that the public agency purchases the pollution sensitive area, such as riparian zone, and prohibit locations of point and non-point sources. Many studies have reported that this new policy is more economical in drinking water supply than the conventional one. However, it is very difficult to determine location and size of the pollution sensitive zone in the watershed. In this paper. we presented the scientific criteria for the priority of the pollution sensitive zone, along with a case study of the upstream watershed of the Paldang Reservoir, Han River. This study includes applications of the analytical hierarchy process(AHP) and a watershed-based land prioritization(WLP) model. After major criteria affecting water quality were selected, the AHP and geographic analysis were performed. The WLP model allowed us to include both quantity and quality criteria, using AHP as the multi-criteria method in making decision and reflecting local characteristics and various needs. By adding a travel-time function, which represents the prototype effectively, the results secured adaptability and scientific objectivity as well. As such, the WLP model appeared to provide reasonable criteria in determining the prioritization of land acquisition. If the tested data are used with a validated travel-time and AHP method is applied after further discussion among experts in such field, highly reliable results can be obtained.

경화제 변화에 따른 WLP(Wafer Level Package)용 신규 Epoxy Resin System의 경화특성

김환건 한국반도체디스플레이기술학회 2022 반도체디스플레이기술학회지 Vol.21 No.2

The curing characteristics of naphthalene type epoxy resin systems according to the change of curing agent were investigated to develop a new next-generation EMC(Epoxy Molding Compound) with excellent warpage characteristics, low thermal expansion, and excellent fluidity for WLP(Wafer Level Package). As epoxy resins, DGEBA, which are representative bisphenol type epoxy resins, NE-16, which are the base resins of naphthalene type epoxy resins, and NET-OH, NET-MA, and NET-Epoxy resins newly synthesized based on NE-16 were used. As a curing agent, DDM(Diamino Diphenyl Methane) and CBN resin with naphthalene moiety were used. The curing reaction characteristics of these epoxy resin systems with curing agents were analyzed through thermal analysis experiments. In terms of curing reaction mechanism, DGEBA and NET-OH resin systems follow the nth curing reaction mechanism, and NE-16, NET-MA and NET-Epoxy resin systems follow the autocatalytic curing reaction mechanism in the case of epoxy resin systems using DDM as curing agent. On the other hand, it was found that all of them showed the nth curing reaction mechanism in the case of epoxy resin systems using CBN as the curing agent. Comparing the curing reaction rate, the epoxy resin systems using CBN as the curing agent showed a faster curing reaction rate than them with DDM as a hardener in the case of DGEBA and NET-OH epoxy resin systems following the same nth curing reaction mechanism, and the epoxy resin systems with a different curing mechanism using CBN as a curing agent showed a faster curing reaction rate than DDM hardener systems except for the NE-16 epoxy resin system. These reasons were comparatively explained using the reaction rate parameters obtained through thermal analysis experiments. Based on these results, low thermal expansion, warpage reduction, and curing reaction rate in the epoxy resin systems can be improved by using CBN curing agent with a naphthalene moiety.

WiMedia UWB MAC에서의 무선 구간 손실을 고려한 TSPEC 추정 방안

김재완(Jaewan Kim),이현정(Hyunjeong Lee),허재두(Jaedoo Huh),이성창(Sungchang Lee) 대한전자공학회 2008 電子工學會論文誌-TC (Telecommunications) Vol.45 No.9

WLP(WiMedia Logical link control Protocol)는 WiMedia UWB 플랫폼 상에서 IP 서비스를 지원하기 위한 프로토콜로서 상위 계층으로부터 전달된 패킷들에 대해서 QoS를 보장하여 전송하려고 할 때, TSPEC 파라미터를 사용하여 DRP 방식의 예약을 하도록 정의하고 있다. 그러나, TSPEC이 알려져 있지 않은 응용의 트래픽의 경우에는 MAS 할당 및 QoS를 보장해 주기 곤란하다. 본 논문에서는 이러한 경우에 대해서 해당 트래픽의 실시간 모니터링을 통해 TSPEC을 추정함으로써 QoS를 보장해 주는 방안을 제안하였다. 우선, TSPEC이 주어지지 않은 트래픽에 대하여 TSPEC 추정기법을 제안한다. 또한, 실제에 있어서 있을 수 있는, 무선 구간에서의 손실이 있는 경우를 가정하고 이를 보상한 TSPEC 파라미터 추정으로 상위계층에서 요구하는 QoS를 보장할 수 있는 TSPEC을 추정하는 기법을 제안하였다. 제안된 기법에 대해서, Imm-ACK 방식을 가정하여, 패킷 손실이 있는 무선 상황에서 제안하는 TSPEC 추정 기법이 해당 트래픽이 요구하는 QoS를 보장하는지 시뮬레이션을 통해 성능 평가를 하였다. WLP(WiMedia Logical link control Protocol) is a protocol to support IP services on the WiMedia UWB platform. It defines that DRP needs to be employed using TSPEC parameters when the packets from upper layer transmit with QoS. However, there is no appropriate means to provide QoS when the TSPEC of the traffic is unknown. In this paper, we propose TSPEC estimation scheme to provide QoS for such unknown applications by monitoring the traffic in realtime. Also, the scheme to estimate the effective TSPEC is proposed that compensate the packet losses in the wireless environment to provide the required QoS. The performances of the proposed TSPEC estimation schemes are evaluate by simulation assuming random wireless packet loss and Imm-ACK mechanism.

Multi-helper Relay Based WUSB/DRD/WLP Protocol in WiMedia Distributed MAC Systems

Seung Beom Lee,Yeonwoo Lee,Seong Ro Lee 보안공학연구지원센터 2014 International Journal of Multimedia and Ubiquitous Vol.9 No.3