• Title/Summary/Keyword: Channel Loss

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The Vision of Sustainability through the Readjustment of Environment and Consciousness: Karen Hesse's Out of the Dust (환경과 의식의 재조정을 통한 생명지속성의 비전 -카렌 헤세의 『모래폭풍을 지나며』)

  • Lee, Chung-Hee
    • Journal of English Language & Literature
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    • v.56 no.2
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    • pp.383-408
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    • 2010
  • This paper intends to suggest the positive, ecological vision of sustainability in Karen Hesse's Out of the Dust that Billie Jo Kelby recovers herself through her readjustment of interior consciousness and outer environment in her tragic situations caused by the Dust Bowl. In spite of her desires for happiness and affluence of home, she loses her mother and brother, and her musical talent as a pianist, and lies in self-abandonment. But she finally raises up herself with her courage and patience, reconciliating with the nature and ameliorating the community by taking care of the devastated landscapes. Hence it is appropriate to approach the loss-recovery process of nature and consciousness with ecological solutions, The Dust Bowl breaks down human mind and body, and eventually leads to the situations of despairs and death. Hesse proposes the primary solution that humans should reconstruct their interior consciousness and participate in recovering the nature because humans are inevitably linked with nature. In this novel, the nature takes a dynamic and active role as a catalyst, reconciling the self with other humans and settling with the conflicting situations in history and culture. This verse novel as an active, self-ordering, and corrective process gives the more intense ecological message. As Hesse defines the setting of Dirty Thirties as a channel of energy, she creates the utmost effects of ecological process that human and environment are part of a total situation, representing the transactional formulation, each conditioned by conditioning to the other. Therefore Billie Jo takes her part as an interpreter and actualizes herself, understanding the nature with metaphor and symbol. Eventually Billie Jo realizes that she should rebuild her environment not out of the dust but in the dust, accepting the reality of Dust Bowl.

Effect of High-Temperature Post-Oxidation Annealing in Diluted Nitric Oxide Gas on the SiO2/4H-SiC Interface (4H-SiC와 산화막 계면에 대한 혼합된 일산화질소 가스를 이용한 산화 후속 열처리 효과)

  • In kyu Kim;Jeong Hyun Moon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.37 no.1
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    • pp.101-105
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    • 2024
  • 4H-SiC power metal-oxide-semiconductor field effect transistors (MOSFETs) have been developed to achieve lower specific-on-resistance (Ron,sp), and the gate oxides have been thermally grown. The poor channel mobility resulting from the high interface trap density (Dit) at the SiO2/4H-SiC interface significantly affects the higher switching loss of the power device. Therefore, the development of novel fabrication processes to enhance the quality of the SiO2/4H-SiC interface is required. In this paper, NO post-oxidation annealing (POA) by using the conditions of N2 diluted NO at a high temperature (1,300℃) is proposed to reduce the high interface trap density resulting from thermal oxidation. The NO POA is carried out in various NO ambient (0, 10, 50, and 100% NO mixed with 100, 90, 50, and 0% of high purity N2 gas to achieve the optimized condition while maintaining a high temperature (1,300℃). To confirm the optimized condition of the NO POA, measuring capacitance-voltage (C-V) and current-voltage (I-V), and time-of-flight secondary-ion mass spectrometry (ToF-SIMS) are employed. It is confirmed that the POA condition of 50% NO at 1,300℃ facilitates the equilibrium state of both the oxidation and nitridation at the SiO2/4H-SiC interface, thereby reducing the Dit.

Method for Spectral Enhancement by Binary Mask for Speech Recognition Enhancement Under Noise Environment (잡음환경에서 음성인식 성능향상을 위한 바이너리 마스크를 이용한 스펙트럼 향상 방법)

  • Choi, Gab-Keun;Kim, Soon-Hyob
    • The Journal of the Acoustical Society of Korea
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    • v.29 no.7
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    • pp.468-474
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    • 2010
  • The major factor that disturbs practical use of speech recognition is distortion by the ambient and channel noises. Generally, the ambient noise drops the performance and restricts places to use. DSR (Distributed Speech Recognition) based speech recognition also has this problem. Various noise cancelling algorithms are applied to solve this problem, but loss of spectrum and remaining noise by incorrect noise estimation at low SNR environments cause drop of recognition rate. This paper proposes methods for speech enhancement. This method uses MMSE-STSA for noise cancelling and ideal binary mask to compensate damaged spectrum. According to experiments at noisy environment (SNR 15 dB ~ 0 dB), the proposed methods showed better spectral results and recognition performance.

Evaluating Relay Beamwidth for Enhanced Coverage and Data Rates in Buoy-Assisted Maritime Communications

  • Kyeongjea Lee;Tae-Woo Kim;Sungyoon Cho;Kiwon Kwon;Dong Ku Kim
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.18 no.4
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    • pp.922-937
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    • 2024
  • Maritime activities are on the rise, there is a growing demand for high-quality communication services that can cover larger areas. However, the transmission of high data rates to maritime users is challenging due to path loss from land base stations, which limits the transmission power. To overcome this challenge, researchers have been exploring the use of buoys in a marine environment as relays for communication technology. This paper proposes a simulation-based approach to investigate the impact of various beamwidths on communication performance when using a buoy as a relay. The objective is to determine the optimal beamwidth that yields the highest data rate for the target location. The approach is based on an offshore wave model where the direction of the buoy changes according to the height of the wave. The study investigates the performance of the relay in the downlink situation using receive beamforming, and the capacity at the user in the three-hop situation is verified using an amplify-and-forward (AF) relay that uses transmit beamforming to the user. The simulation results suggest that the beamwidth of the relay should be adjusted according to the wave conditions to optimize the data rate and relay position that satisfies a data rate superior to the direct path to the target position. Using a buoy as a relay can be a promising solution for enhancing maritime communications, and the simulation-based approach proposed in this paper can provide insights into how to optimize beamwidth for effective communication system design and implementation. In conclusion, the study results suggest that the use of buoys as relays for maritime communication is a feasible solution for expanding coverage and enhancing communication quality. The proposed simulation-based approach provides a useful tool for identifying relay beamwidths for achieving higher data rates in different wave conditions. These findings have significant implications for the design and deployment of communication systems in maritime environments.

Genetic polymorphisms in external apical root resorption and orthodontic tooth movements: A systematic review

  • Ana Luiza Cabral de Avila Andrade;Yasmin Dias de Almeida Pinto;Bernardo Emerenciano Barros Maia;Joice Dias Correa;Diogo de Azevedo Miranda;Flavio Ricardo Manzi;Izabella Lucas de Abreu Lima
    • The korean journal of orthodontics
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    • v.54 no.5
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    • pp.284-302
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    • 2024
  • Objective: External apical root resorption (EARR) is characterized by permanent loss of dental structure at the root apex. This study aimed to systematically review gene polymorphisms associated with EARR in orthodontic patients. Methods: Electronic database searches were performed across several databases. Results: This systematic review included 21 studies. Outcome measures were based on tooth dimensions observed on radiographs obtained before and after treatment. Polymorphisms in the following genes were genotyped using polymerase chain reaction-restriction fragment length polymorphism analysis: purinergic-receptor-P2X, ligand-gated ion channel 7 (P2RX7), caspase-1/interleukin-converting enzyme (CASP1/ICE), caspase-5 (CASP5), IL-1beta (IL1B), IL-1alpha (IL1A), interleukin-1 receptor antagonist gene (IL1RN), tissue non-specific alkaline phosphatase (TNSALP), tumor necrosis factor-alpha (TNFα), tumor necrosis factor receptor superfamily gene member 11a (TNFRSF11A), secreted phosphoprotein 1 (SPP1), tumor necrosis factor receptor superfamily gene member 11b (TNFRSF11B), interleukin 17A (IL17), interleukin 6 (IL6), receptor activator of nuclear factor-kappa B (RANK), osteoprotegerin (OPG), stromal antigen 2 (STAG2), vitamin D receptor (VDR), cytochrome P450 family 24 subfamily A member 1 (CYP24A1), cytochrome P450 family 27 subfamily B (CYP27B1), group-specific component (GC), and interleukin-1 receptor-associated kinases 1 (IRAK1). Conclusions: Almost all studies suggested that IL1 gene is associated with EARR. Additionally, P2RX7 may be an important factor contributing to the etiopathogenesis of EARR. TNFRSF11A, SPP1, IL1RN, IL6, TNFRSF11B, STAG2, VDR, IRAK1, IL-17, CASP1/ICE and CASP5 have been identified in isolated studies. Further observational studies are needed to better explain the association between these genes and EARR.

Innovative approaches to the health problems of rural Korea (한국농촌보건(韓國農村保健)의 문제점(問題點)과 개선방안(改善方案))

  • Loh, In-Kyu
    • Journal of agricultural medicine and community health
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    • v.1 no.1
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    • pp.5-9
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    • 1976
  • The categories of national health problems may be mainly divided into health promotion, problems of diseases, and population-economic problems which are indirectly related to health. Of them, the problems of diseases will be exclusively dealt with this speech. Rurality and Disease Problems There are many differences between rural and urban areas. In general, indicators of rurality are small size of towns, dispersion of the population, remoteness from urban centers, inadequacy of public transportation, poor communication, inadequate sanitation, poor housing, poverty, little education lack of health personnels and facilities, and in-accessibility to health services. The influence of such conditions creates, directly or indirectly, many problems of diseases in the rural areas. Those art the occurrence of preventable diseases, deterioration and prolongation of illness due to loss of chance to get early treatment, decreased or prolonged labour force loss, unnecessary death, doubling of medical cost, and economic loss. Some Considerations of Innovative Approach The followings art some considerations of innovative approaches to the problems of diseases in the rural Korea. 1. It would be essential goal of the innovative approaches that the damage and economic loss due to diseases will be maintained to minimum level by minimizing the absolute amount of the diseases, and by moderating the fee for medical cares. The goal of the minimization of the disease amount may be achieved by preventive services and early treatment, and the goal of moderating the medical fee may be achieved by lowering the prime cost and by adjusting the medical fees to reasonable level. 2. Community health service or community medicine will be adopted as a innovative means to disease problems. In this case, a community is defined as an unit area where supply and utilization of primary service activities can be accomplished within a day. The essential nature o the community health service should be such activities as health promotion, preventive measures, medical care, and rehabilitation performing efficiently through the organized efforts of the residents in a community. Each service activity should cover all members of the residents in a community in its plan and performance. The cooperation of the community peoples in one of the essential elements for success of the service program, The motivations of their cooperative mood may be activated through several ways: when the participation of the residents in service program of especially the direct participation of organized cooperation of the area leaders art achieved through a means of health education: when the residents get actual experience of having received the benefit of good quality services; and when the health personnels being armed with an idealism that they art working in the areas to help health problems of the residents, maintain good human relationships with them. For the success of a community health service program, a personnel who is in charge of leadership and has an able, a sincere and a steady characters seems to be required in a community. The government should lead and support the community health service programs of the nation under the basis of results appeared in the demonstrative programs so as to be carried out the programs efficiently. Moss of the health problems may be treated properly in the community levels through suitable community health service programs but there might be some problems which art beyond their abilities to be dealt with. To solve such problems each community health service program should be under the referral systems which are connected with health centers, hospitals, and so forth. 3. An approach should be intensively groped to have a physician in each community. The shortage of physicians in rural areas is world-wide problem and so is the Korean situation. In the past the government has initiated a system of area-limited physician, coercion, and a small scale of scholarship program with unsatisfactory results. But there might be ways of achieving the goal by intervice, broadened, and continuous approaches. There will be several ways of approach to motivate the physicians to be settled in a rural community. They are, for examples, to expos the students to the community health service programs during training, to be run community health service programs by every health or medical schools and other main medical facilities, communication activities and advertisement, desire of community peoples to invite a physician, scholarship program, payment of satisfactory level, fulfilment of military obligation in case of a future draft, economic growth and development of rural communities, sufficiency of health and medical facilities, provision of proper medical care system, coercion, and so forth. And, hopefully, more useful reference data on the motivations may be available when a survey be conducted to the physicians who are presently engaging in the rural community levels. 4. In communities where the availability of a physician is difficult, a trial to use physician extenders, under certain conditions, may be considered. The reason is that it would be beneficial for the health of the residents to give them the remedies of primary medical care through the extenders rather than to leave their medical problems out of management. The followings are the conditions to be considered when the physician extenders are used: their positions will be prescribed as a temporary one instead of permanent one so as to allow easy replacement of the position with a physician applicant; the extender will be under periodic direction and supervision of a physician, and also referral channel will be provided: legal constraints will be placed upon the extenders primary care practice, and the physician extenders will used only under the public medical care system. 5. For the balanced health care delivery, a greater investment to the rural areas is needed to compensate weak points of a rurality. The characteristics of a rurality has been already mentioned. The objective of balanced service for rural communities to level up that of urban areas will be hard to achieve without greater efforts and supports. For example, rural communities need mobile powers more than urban areas, communication network is extremely necessary at health delivery facilities in rural areas as well as the need of urban areas, health and medical facilities in rural areas should be provided more substantially than those of urban areas to minimize, in a sense, the amount of patient consultation and request of laboratory specimens through referral system of which procedures are more troublesome in rural areas, and more intensive control measures against communicable diseases are needed in rural areas where greater numbers of cases are occurred under the poor sanitary conditions.

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Threshold-dependent Occupancy Control Schemes for 3GPP's ARQ (3GPP의 ARQ를 위한 threshold에 의존하는 점유량 조절 방식)

  • Shin, Woo-Cheol;Park, Jin-Kyung;Ha, Jun;Choi, Cheon-Won
    • Journal of IKEEE
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    • v.9 no.2 s.17
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    • pp.123-135
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    • 2005
  • 3GPP RLC protocol specification adopted a window-controlled selective-repeat ARQ scheme for provisioning reliable data transmission. Inevitably, the re-ordering issue arises in the 3GPP's ARQ since it belongs to the selective-repeat ARQ clan. A long re-ordering time results in the degradation of throughput and delay performance, and may invoke the overflow of the re-ordering buffer. Also, the re-ordering time must be regulated to meet the requirements of some services which are both loss-sensitive and delay-sensitive. In the 3GPP's ARQ, we may deflate the occupancy of the re-ordering buffer by reducing the window size and/or length of the status report period. Such a decrease, however, deteriorates the throughput and delay performance and encroaches the resource of the reverse channel. Aiming at reducing the occupancy at the re-ordering buffer while suppressing the degradation of throughput and delay performance, we propose threshold-dependent occupancy control schemes, identified as post-threshold and pre-threshold schemes, as supplements to the 3GPP's ARQ. For judging the effectiveness of the proposed schemes, we investigate peak occupancy, maximum throughput and average delay in the practical environment involving fading channels. From the simulation results, we observe that the proposed schemes invoke the performance trade-off between occupancy and throughput in general. Also, we reveal that the post-threshold scheme is able to improve the throughput and delay performance of the ordinary 3GPP's ARQ without inflating the occupancy of the re-ordering buffer.

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PKHD1 Gene Silencing May Cause Cell Abnormal Proliferation through Modulation of Intracellular Calcium in Autosomal Recessive Polycystic Kidney Disease

  • Yang, Ji-Yun;Zhang, Sizhong;Zhou, Qin;Guo, Hong;Zhang, Ke;Zheng, Rong;Xiao, Cuiying
    • BMB Reports
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    • v.40 no.4
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    • pp.467-474
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    • 2007
  • Autosomal recessive polycystic kidney disease (ARPKD) is one of the important genetic disorders in pediatric practice. Mutation of the polycystic kidney and hepatic disease gene 1 (PKHD1) was identified as the cause of ARPKD. The gene encodes a 67-exon transcript for a large protein of 4074 amino acids termed fibrocystin, but its function remains unknown. The neoplastic-like in cystic epithelial proliferation and the epidermal growth factor/epidermal growth factor receptor (EGF/EGFR) axis overactivity are known as the most important characteristics of ARPKD. Since the misregulation of $Ca^{2+}$ signaling may lead to aberrant structure and function of the collecting ducts in kidney of rat with ARPKD, present study aimed to investigate the further mechanisms of abnormal proliferation of cystic cells by inhibition of PKHD1 expression. For this, a stable PKHD1-silenced HEK-293T cell line was established. Then cell proliferation rates, intracellular $Ca^{2+}$ concentration and extracellular signal-regulated kinase 1/2 (ERK1/2) activity were assessed after treatment with EGF, a calcium channel blocker and agonist, verapamil and Bay K8644. It was found that PKHD1-silenced HEK-293T cell lines were hyperproliferative to EGF stimulation. Also PKHD1-silencing lowered the intracellular $Ca^{2+}$ and caused EGF-induced ERK1/2 overactivation in the cells. An increase of intracellular $Ca^{2+}$ in PKHD1-silenced cells repressed the EGF-dependent ERK1/2 activation and the hyperproliferative response to EGF stimulation. Thus, inhibition of PKHD1 can cause EGF-induced excessive proliferation through decreasing intracellular $Ca^{2+}$ resulting in EGF-induced ERK1/2 activation. Our results suggest that the loss of fibrocystin may lead to abnormal proliferation in kidney epithelial cells and cyst formation in ARPKD by modulation of intracellular $Ca^{2+}$.

Anti-arthritic Properties of ShinEumHur-Herbal Acupuncture Assessed by Knee Circumference, Squeak Threshold and Weight Distribution Ratio in Rats (흰쥐의 adjuvant-induced knee arthritis에 대한 신음허 약침의 치료효과)

  • Kim Gun-Ho;Hahm Dae-Hyun;Lee Han-Chang;Yeom Mijung;Han Dong-Oh;Zhao Mei Ai;Shim Insop;Kim Jang-Hyun;Lee Hye-Jung
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.18 no.4
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    • pp.1001-1006
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    • 2004
  • In order to examine the anti-arthritic properties of ShinEumHur(SEH)-herbal acupuncture, an adjuvant-induced arthritic rat was generated by the intra-articular injection of dried cells of Mycobacterium tuberculosis emulsified in squalene into the right knee joint. Fifty microliter of SEH extract was injected into Zusanli(ST36) acupoint on the ipsilateral hind paw every other day for 2 weeks. The body weight, knee circumference, squeak threshold, and weight distribution ratio were analyzed as the assessment methods addressing arthritic symptoms such as arthritic pain, edema, and tenderness. The weight distribution ratio was measured by a digital-type analgesia instrument using the dual channel scale that separately measures the weight the arthritic rat distributes to each hind paw, and thus quantifies both of swelling and pain severities at once. The therapeutic effects of SEH-herbal acupuncture, assessed by squeaking threshold and weight distribution ratio, were observed on 8th day after the arthritis induction as compared to saline group and control group. On 10th day, SEH-herbal acupuncture therapy significantly started to alleviate the growing pattern of knee circumference of an arthritic rat in the range of 0.2㎝. However, the loss of body weight was not significantly recovered. Taken together, the SEH-herbal acupuncture exhibited the significant therapeutic efficiency to treat adjuvant-induced monoarthritis in rat.

A Study on the Comparison and Analysis of Debris Reduction System on Small Bridge (소교량 유송잡물 저감시설의 비교 분석 연구)

  • Kim, Sung-Joong;Jung, Do-Joon;Kang, Joon-Gu;Yeo, Hong-Koo;Kim, Jong-Tae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.3
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    • pp.31-41
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    • 2016
  • Damage to structures, such as bridge piers, are increasing rapidly due to the debris moving along rivers at the time of flooding. Therefore, the debris fin, debris deflector and debris sweeper, which are debris reduction systems, were produced in this study and an accumulation experiment was carried out on the experimental channel according to the existence of the reduction system. The debris fin is the reduction system that creates parallel flow on debris accumulated on the bridge to pass through the bridge, which was produced using wood. In addition, the debris deflector was produced using steel pipes and it has the type of detouring the direction of debris. The debris sweeper passes the debris using the magnetic force rotation of a screw-shaped cylindrical structure by water flow and it was produced using acrylic material. The experiment was carried out by analyzing the level of accumulation according to the hardness and dropping method of the debris and comparing the accumulation rate of reduction systems, and the experiment was carried out 5 times. According to the experimental results, there was a difference in the accumulation rate according to the type of reduction system and the shape of debris, and it often depended significantly on the initial shape of debris accumulation. The direct debris reduction effect on the bridge was higher in the order of the debris deflector, debris sweeper and debris fin, but in case of the debris deflector, damage, such as stream turbulence, changes in water level and river bed, and the loss of deflector can occur due to debris accumulated directly on the debris deflector. Therefore, it is necessary to design the debris deflector considering these issues.