• Title/Summary/Keyword: One-Time MAC

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Between Dystopia and Utopia A Comparative Study on Cormac MacCarthy's The Road and J.M. Coetzee's The Childhood of Jesus (디스토피아와 유토피아 사이 - 코멕 매카시의 『더 로드』와 존 쿳시의 『예수의 어린시절』 비교연구)

  • Jeon, So-Young
    • Cross-Cultural Studies
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    • v.40
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    • pp.91-110
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    • 2015
  • Both Plato and More imagined alternative ways of organizing society. What is common to both authors, then, is the fact that they resorted to fiction to discuss other options. They differed, however, in the way they presented that fiction. The concept of utopia is no doubt an attribute of modern thought, and one of its most visible consequences. But one of the main features of utopia as a literary genre is its relationship with reality. Utopists depart from the observation of the society they live in, note down the aspects that need to be changed and imagine a place where those problems have been solved. After the two World Wars, the twentieth century was predominantly characterized by man's disappointment at the perception of his own nature. In this context, utopian ideals seemed absurd and the floor was inevitably left to dystopian discourse. Both The Road by Cormac MacCarthy and The Childhood of Jesus by J. M. Coetzee can be called critical dystopia and critical utopia as they represent the imaginary place and time that author intended a contemporaneous reader to view as better or worse than contemporary society but with difficult problems that the described society may or may not be able to solve. As a changed adventure narrative, they have something in common like open ending, father and son relationship and religious allegory. But the most important thing is that they express the utopian impulse that is still energetic and transforming in the post-modern society.

The Relationship between Spirituality and Fighting Spirit among Cancer Patients in Korea (암환자의 영성과 투병정신과의 관계)

  • Kim, Joohyung;Lee, Suk Jeong;Lee, Won Hee
    • Korean Journal of Adult Nursing
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    • v.17 no.4
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    • pp.583-591
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    • 2005
  • Purpose: The purpose of this study was to examine the relationship between spirituality and a fighting spirit among the patients with cancer. Methods: The participants were 223 patients diagnosed stomach, colorectal or breast cancer, and who were in chemotherapy or follow up care. The study design was cross-sectional at the time of the data collection. The degree of spirituality was measured by the Korean version of WHOQOL Spirituality, Religiousness and Personal Beliefs (SRPB) Pilot Test Module, and fighting spirit was measured by the scores of Mental Adjustment to Cancer(MAC) scale. Results: The score of love appeared to be higher in the patients with follow up care than the patients with treatment(p<0.05) and the score of believing was much higher in patients with recurrence than the patients without (p<0.05). There was a statistically significant correlation among hope, believing, love, forgiveness and acceptance, and fighting spirit. In the multiple regression analysis, hope and believing explained much variance of the fighting spirit. Conclusion: These finding showed that the more hopeful and believing patients with cancer had higher scores of fighting spirit, which was known to be one of the most active coping style in adjusting to cancer.

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Static Worst-Case Energy and Lifetime Estimation of Wireless Sensor Networks

  • Liu, Yu;Zhang, Wei;Akkaya, Kemal
    • Journal of Computing Science and Engineering
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    • v.4 no.2
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    • pp.128-152
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    • 2010
  • With the advance of computer and communication technologies, wireless sensor networks (WSNs) are increasingly used in many aspects of our daily life. However, since the battery lifetime of WSN nodes is restricted, the WSN lifetime is also limited. Therefore, it is crucial to determine this limited lifetime in advance for preventing service interruptions in critical applications. This paper proposes a feasible static analysis approach to estimating the worstcase lifetime of a WSN. Assuming known routes with a given sensor network topology and SMAC as the underlying MAC protocol, we statically estimate the lifetime of each sensor node with a fixed initial energy budget. These estimations are then compared with the results obtained through simulation which run with the same energy budget on each node. Experimental results of our research on TinyOS applications indicate that our approach can safely and accurately estimate worst-case lifetime of the WSN. To the best of our knowledge, our work is the first one to estimate the worst-case lifetime of WSNs through a static analysis method.

Turbulence Driven by Supernova Explosions in a Radiatively-Cooling Magnetized Interstellar Medium

  • KIM JONGSOO;BALSARA DINSHAW;MAC LOW MORDECAI-MARK
    • Journal of The Korean Astronomical Society
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    • v.34 no.4
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    • pp.333-335
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    • 2001
  • We study the properties of supernova (SN) driven interstellar turbulence with a numerical magnetohydrodynamic (MHD) model. Calculations were done using the RIEMANN framework for MHD, which is highly suited for astrophysical flows because it tracks shocks using a Riemann solver and ensures pressure positivity and a divergence-free magnetic field. We start our simulations with a uniform density threaded by a uniform magnetic field. A simplified radiative cooling curve and a constant heating rate are also included. In this radiatively-cooling magnetized medium, we explode SNe one at a time at randomly chosen positions with SN explosion rates equal to and 12 times higher than the Galactic value. The evolution of the system is basically determined by the input energy of SN explosions and the output energy of radiative cooling. We follow the simulations to the point where the total energy of the system, as well as thermal, kinetic, and magnetic energy individually, has reached a quasi-stationary value. From the numerical experiments, we find that: i) both thermal and dynamical processes are important in determining the phases of the interstellar medium, and ii) the power index n of the $B-p^n$ relation is consistent with observed values.

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A MAC Protocol for Voice/Data Integrated Services Using R_ALOHA Scheme In Wideband Wireless Networks (광대역 무선망에서 R_ALOHA 기법을 적용한 음성/데이타 통합 서비스 UC 프로토콜)

  • 임인택
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.3 no.1
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    • pp.155-162
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    • 1999
  • In this paper, an R_ALOHA_CDMA protocol is proposed for voice and data integrated services in the hybrid TDMA/CDMA wireless networks. In the hybrid TDMA/CDMA systems, the backward logical channels are composed of time slots with multiple spreading codes per slot. In the proposed protocol, a voice terminal can reserve a spreading code to transmit voice packets during a talkspurt. On the other hand, whenever a data terminal generates a packet, it transmits the packet through one of the available spreading codes. Throughout the results, it is shown that the system capacity increases in proportion to the number of spreading codes.

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Hypergraph Game Theoretic Solutions for Load Aware Dynamic Access of Ultra-dense Small Cell Networks

  • Zhu, Xucheng;Xu, Yuhua;Liu, Xin;Zhang, Yuli;Sun, Youming;Du, Zhiyong;Liu, Dianxiong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.2
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    • pp.494-513
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    • 2019
  • A multi-channel access problem based on hypergraph model in ultra-dense small cell networks is studied in this paper. Due to the hyper-dense deployment of samll cells and the low-powered equipment, cumulative interference becomes an important problem besides the direct interference. The traditional binary interference model cannot capture the complicated interference relationship. In order to overcome this shortcoming, we use the hypergraph model to describe the cumulative interference relation among small cells. We formulate the multi-channel access problem based on hypergraph as two local altruistic games. The first game aims at minimizing the protocol MAC layer interference, which requires less information exchange and can converge faster. The second game aims at minimizing the physical layer interference. It needs more information interaction and converges slower, obtaining better performance. The two modeled games are both proved to be exact potential games, which admit at least one pure Nash Equilibrium (NE). To provide information exchange and reduce convergecne time, a cloud-based centralized-distributed algorithm is designed. Simulation results show that the proposed hypergraph models are both superior to the existing binary models and show the pros and cons of the two methods in different aspects.

A retrospective study of incidental findings occurring in a consecutive case series of lateral cephalograms of 12- to 20-year-old patients referred for routine orthodontic treatment

  • MacDonald, David;Patel, Akash;Zou, Bingshuang;Yen, Edwin;Vora, Siddharth R.
    • Imaging Science in Dentistry
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    • v.52 no.3
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    • pp.295-302
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    • 2022
  • Purpose: Lateral cephalograms of orthodontic patients may contain incidental findings that could potentially lead to harm. Materials and Methods: The lateral cephalograms of 1765 consecutive 12- to 20-year-old patients, being considered for routine orthodontic treatment, were retrospectively reviewed. These patients were considered normal, because no abnormalities were found either in their medical history or on their clinical examination. Results: The overall prevalence of incidental findings was 18.8%, of which 10.3% were ponticulus posticus and 4.2% were bridging of the sella turcica. Although occipital spurs and ponticulus posticus were more prevalent in males, the size of the sella turcicas did not differ between sexes. Of the 1156 patients completing treatment about 2 years later, only one lateral cephalogram displayed progression of the ponticulus posticus in that time. Conclusion: The prevalence of incidental findings on lateral cephalograms of otherwise normal orthodontic 12- to 20-year-old patients was almost a fifth, of which ponticulus posticus, vertebral fusion, and enlarged parietal foramina were clinically significant.

The Comparison of RBS and TDP for the Sensor Networks Synchronization

  • Lee, Hyo-Jung;Kim, Byung-Chul;Kwon, Young-Mi
    • Journal of Information Processing Systems
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    • v.1 no.1 s.1
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    • pp.70-74
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    • 2005
  • Sensor networks have emerged as an interesting and important research area in the last few years. These networks require that time be synchronized more precisely than in traditional Internet applications. In this paper, we compared and analyzed the performance of the RBS and TDP mechanisms in the view of the number of generated messages and the synchronization accuracy. The reason that we chose be RBS ad the TDP mechanism to be compared is because the RES is an innovative method to achieve the high accurate synchronization. And TDP is a new method taking over the NTP method which has been used widely in the Internet. We simulated the performance of two methods assuming the IEEE 802.11 CSMA/CA MAC. As for the number of nodes in the sensor networks, two situations of 25 (for the small size network) and 100 (for the large size network) nodes are used. In the aspect of the number of messages generated for the synchronization, TDP is far better than RBS. But, the synchronization accuracy of RBS is far higher than that of TDP. We cm conclude that in a small size sensor networks requiring very high accuracy, such as an application of very high speed objects tracking in a confined space, the RBS is more proper than TDP even though the RBS may generate more traffic than TDP. But, in a wide range sensor networks with a large number of nodes, TDP is more realistic though the accuracy is somewhat worse than RBS because RBS may make so many synchronization messages, and then consume more energies at each node. So, two mechanisms may be used selectively according to the required environments, without saying that the one method is always better than the other.

Development of a Conjunctive Surface-Subsurface Flow Model for Use in Land Surface Models at a Large Scale: Part II. Model Implementation (대규모 육지수문모형에서 사용 가능한 지표면 및 지표하 연계 물흐름 모형의 개발: II. 모형적용)

  • Choi, Hyun-Il
    • Journal of the Korean Society of Hazard Mitigation
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    • v.8 no.3
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    • pp.23-27
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    • 2008
  • The new conjunctive surface-subsurface flow model at a large scale was developed by using a 1-D Diffusion Wave (DW) model for surface flow interacting with the 3-D Volume Averaged Soil-moisture Transport (VAST) model for subsurface flow for the comprehensive terrestrial water and energy predictions in Land Surface Models (LSMs). A selection of numerical implementation schemes is employed for each flow component. The 3-D VAST model is implemented using a time splitting scheme applying an explicit method for lateral flow after a fully implicit method for vertical flow. The 1-D DW model is then solved by MacCormack finite difference scheme. This new conjunctive flow model is substituted for the existing 1-D hydrologic scheme in Common Land Model (CLM), one of the state-of-the-art LSMs. The new conjunctive flow model coupled to CLM is tested for a study domain around the Ohio Valley. The simulation results show that the interaction between surface flow and subsurface flow associated with the flow routing scheme matches the runoff prediction with the observations more closely in the new coupled CLM simulations. This improved terrestrial hydrologic module will be coupled to the Climate extension of the next-generation Weather Research and Forecasting (CWRF) model for advanced regional, continental, and global hydroclimatological studies and the prevention of disasters caused by climate changes.

The Clinical Comparison between Open Surgery and Percutaneous Endoscopic Lumbar Discectomy in Extraforaminal Lumbar Disc Herniation

  • Jeong, Jin-Seok;Lee, Sang-Ho;Lee, Sang-Jin;Hwang, Byeong-Wook
    • Journal of Korean Neurosurgical Society
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    • v.39 no.6
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    • pp.413-418
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    • 2006
  • Objective : The objective of this study is to evaluate and compare the clinical results between classical open surgery and percutaneous endoscopic lumbar discectomy[PELD] in cases of extraforaminal lumbar disc herniation. Methods : We obtained the clinical data from 47 patients with extraforaminal lumbar disc herniations who underwent the open paramedian muscle-splitting approach or percutaneous endoscopic lumbar discectomy[PELD] between January 2001 and February 2004. This study consisted of patients with soft disc extraforaminal herniations. The patients were assessed with the visual analogue scale[VAS] and MacNab's criteria before surgery, just before discharge, and postoperative 1 year. Results : There were 25 cases in the open surgery group and 22 cases in the PELD group. The average operating time was $78{\pm}36.71\;min$ in the PELD group and $110{\pm}29.68\;min$ in the open surgery group. The mean hospital stay was $2.73{\pm}2.62$ days in the PELD group and $7.68{\pm}2.59$ days in the open surgery group. VAS decreased from $8.34{\pm}0.66$ to $1.29{\pm}2.27$ in the PELD group and from $8.40{\pm}1.40$ to $1.70{\pm}1.72$ in the open surgery group at the one-year follow-up. The success rate of PELD was 86.4%, compared with 80.0% for open surgery. However, there were no statistically significant difference between two groups for success rate and VAS. Conclusion : Although the success rates were similar in both groups, PELD is less invasive, faster, and safe procedure than open surgery for extraforaminal disc herniation in selected patients.