• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2001년도 하계종합학술대회 논문집(1)
• /
• pp.293-296
• /
• 2001

In this paper, we investigate two soft handover algorithms used in the different mobile communication system. These different systems are IS-95 system and 3GPP system. The performances of two different soft handover are compared under similar conditions in terms of propagation, environment and mobility behavior. For performance comparison of soft handover, we model cell environment, radio channel and mobility. With these models the computer simulation are performed and the result of computer simulation are reported.

• Architectural research
• /
• 제9권2호
• /
• pp.1-9
• /
• 2007

As aging is notably developed, the elderly find it challenging to get around in housing chosen in their midlife, and seek for an alternative residential setting enabling them to continue the independent living. This research focuses on the residential mobility of the elderly who have recently moved to senior housing, and also is to investigate their residential satisfaction at previous residence. As a cross-sectional study, the research adopts the self-administered questionnaire survey. The questionnaires are mailed out, and one out of the two responses is retrieved. To investigate the residential mobility of the elderly, the research model is constructed based upon Morris and Winter's Housing Adjustment Theory. The result shows that the residential mobility of elderly from previous residence is a need-based choice, want-driven behavior and demand-oriented decision to maintain continued independence and utilize resources available during the aging process. Also, it is found that the vast majority of both co-op and rental households are satisfied with their previous residential environment. The previous residential satisfaction of co-op elderly is significantly influenced by household and housing characteristics, housing norm status, and environmental needs for independent living while only housing norm status is a significant predictor to explain the previous residential satisfaction of rental elderly.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제9권12호
• /
• pp.5028-5057
• /
• 2015

In this paper, a new mathematical scheme of Macro Handover Management (MHM) in F-HMIPv6 networks based on Location Based Services (LBS) is proposed. Previous schemes based on F-HMIPv6 protocol usually suffer from three major drawbacks: First, They don't exploit the information about the user mobility behavior in order to reduce handover effects. Second, they only focus on the micro mobility level. Third, they don't consider the quality of service (QoS) of the traffic. The proposed MHM scheme avoids these drawbacks using the available information about Mobile Node (MN) such as user mobility patterns and MN's velocity to predict handover and improve network's QoS. It also takes the traffic type in consideration since it presents a major factor in locating QoS for the user. MHM is analyzed and compared with the F-HMIPv6. The results show that MHM improves the performance in terms of packet delivery cost, location update cost, and handover latency. The design of MHM comprises software package in the MN in addition to a hardware part in the network side. It has implications for communication, design, and pricing of mobile services.

• 한국세라믹학회지
• /
• 제37권7호
• /
• pp.686-692
• /
• 2000

Tin-doped In2O3 (ITO) films were fabricated using a d.c. magnetron reactive sputteirng of a In-10 wt% Sn alloy target in an Ar and O2 gas mixture. To understand the behavior of the carrier mobility in ITO films with O2 partial pressure, the resistivity, carrier concentration and mobility, film density, and intrinsic stress in the films were measured with O2 partial pressure. It was found experimentally that the carrier mobility increased rapidly as the film density increased. In the ITO film with the density close to theoretical one, the mean free path was the same as the columnar diameter. This indicated that the mobility in ITO films was strongly influenced by the crystall size. However, in the case where the film density was smaller than a theoretical density, the mean free paths were also smaller the columnar diameter. It was analyzed that the electron scattering at pores and holes within the crystalline was the major obstacle for electron conduction in ITO films. The measurement of intrinsic stress in ITO films also made it clear that the density of ITO films was controlled by the bombardment of oxygen neutrals on the growing film.

• 한국물환경학회지
• /
• 제27권1호
• /
• pp.115-119
• /
• 2011

The mobility of groundwater in the soil environment has an important role in the soil environment and absorption of plant. Therefore, studies on the mobility of groundwater considering the physical and chemical properties of soil is very important. In this study, movement of water due to change in soil particle size were observed by capillary rise. The height of the capillaries was measured according to capillary diameter, temperature and solution concentration. The inner diameter of each capillary itself is 0.012, 0.016, 0.024, 0.027 cm, and experiments were performed at $22^{\circ}C$. As a result, the height of the capillaries decreased with increasing capillary diameter, and the solution temperature but increased with increasing concentration. Changes in the height of the capillaries are interpreted to related with surface tension by the Young-Laplace equation. Also on the mobility of groundwater, the increase of water and soil temperatures can be significant factors caused by ion strength and global warming as well as pores in the soil particles. The results of this study is considered to provide the basic data on the behavior of groundwater in the soil environment.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2005년도 춘계학술대회 논문집
• /
• pp.1390-1393
• /
• 2005

The hardening model based on the dislocation mechanics is employed to study the experimentally observed high tensile elongations of NiAl along the [110] orientation at intermediate temperatures. In the hardening model proposed, a mobility of dislocation is assumed to be restricted to glide through the slip plane by forest dislocation and thermally activated cross-slip event. Overall deformation behavior of NiAl was greatly influenced by temperature-dependent dislocation mobility that both experimental and simulated yield stresses decreased as temperature increased. The results of simulation showed anomalous hardening behaviors analogous to those of experiment at certain circumstances. This behavior occurred due to the hardening contributions generated by cross-slip events that disable the dislocation motion in the primary slip systems. By comparing simulation results with experiments, it is confirmed that the proposed hardening model can represent anomalous tensile elongations due to the hardening by forest dislocations and cross-slip events.

• 한국방사성폐기물학회:학술대회논문집
• /
• 한국방사성폐기물학회 2017년도 추계학술논문요약집
• /
• pp.151-152
• /
• 2017

• 대한지리학회지
• /
• 제46권6호
• /
• pp.781-796
• /
• 2011

우리나라 인구의 급격한 노령화 추세로 인해 노인 인구의 모빌리티는 중요한 사회적 이슈가 되어 있다. 본 연구는 청장년과 비교한 노인의 통행행태의 특성을 검토하고 세계에서 가장 빠른 노령화가 진행되는 우리나라에서 그러한 특성이 어떻게 변화하고 있는지를 살펴보고자 한다. 이를 위해 본 연구는 2002년도와 2006년도의 수도권 가구통행실태조사 자료를 분석한다. 연구 결과, 노인통행은 청장년과는 많은 측면에서 큰 차이들을 보이며, 노인 인구, 특히 65세에서 69세 사이의 '젊은' 노인 인구의 모빌리티는 크게 증가한 것을 알 수 있었다. 최근의 도시 대중교통체계 개편은 이러한 노인 인구의 모빌리티 증진에 영향을 미친 것으로 보인다.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
• /
• 제14권3호
• /
• pp.276-280
• /
• 2008

무선 센서 망에서 이동성 지원을 위한 많은 데이타 전달 프로토콜들이 군인들이나 구조원과 같은 싱크의 이동 궤적이 랜덤하다는 가정 아래서 디자인되어왔다. 하지만, 많은 응용에서, 예를 들면 전쟁 지역에서 작전 상황 중의 군인의 이동 궤적과 같은, 싱크의 이동성은 미리 결정될 수 있다. 본 논문에서, 우리는 싱크들의 예측 가능한 이동성을 고려하여 소스 노드로부터 이동하는 싱크까지 데이타를 우회 없이 직행으로 전달할 수 있는 싱크의 예측 가능한 이동성 기반 데이타 전달 프로토콜을 제안한다. 또한, 우리는 기존의 랜덤한 이동성 기반의 데이타 전달 프로토콜들과의 성능 비교를 통해 예측 가능한 이동성 기반 데이타 전달 프로토콜의 향상성을 증명한다.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
• /
• pp.280.2-280.2
• /
• 2016

The graphene, a single atomic sheet of graphite, has attracted tremendous interest owing to its novel properties including high intrinsic mobility, optical transparency and flexibility. However, for more diverse application of graphene devices, it is essential to tune its transport behavior by shifting Dirac Point (DP) of graphene. So, in the following context, we suggest a method to tune structural and electronic properties of graphene using atomic layer deposition. By atomic layer deposition of zinc oxide (ZnO) on graphene using 4-mercaptophenol as linker, we can fabricate n-doped graphene. Through ${\pi}-{\pi}$ stacking between chemically inert graphene and 4-mercaptophenol, conformal deposition of ZnO on graphene was enabled. The electron mobility of graphene TFT increased more than 3 times without considerably decreasing the hole mobility, compared to the pristine graphene. Also, it has high air stability. This ZnO doping method by atomic layer deposition can be applicable to large scale array of CVD graphene TFT.