• Title/Summary/Keyword: frequency problem

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A Literature Review on the Adolescent Substance Abuse (청소년 물질남용과 관련된 문헌 고찰)

  • Kim, Kwuy-Bun;Lee, Kyung-Ho
    • Journal of East-West Nursing Research
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    • v.4 no.1
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    • pp.44-56
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    • 1999
  • Substance abuse, which leads to juvenile delinquency and other troubles, is one of the most serious problems for the adolescents today. The frequency of the adolescent substance abuse has been growing every year, but the effective methods to cope with the problem have not been well developed yet. The purpose of this study is to investigate into the more favorable ways by review the literature on substance abuse systematically. This study is a research based on the overview of the literature so that we may identify the present conditions of the adolescent substance abuse, its types, its problems and the nursing intervention. This literature review results in the following suggestions. Substance abuse is prevalent among the adolescents enough to be considered as one of our society's major problems. So policy makers as well as government and private agencies should recognize the seriousness of substance abuse and associated problem behaviors. Moreover, it is necessary that the adolescents should remind themselves of the seriousness of substance abuse. Once the health professionals notice the adolescents' involvement in substance abuse, they need to approach them with the parental concern in order to establish rapport with them by using tactful questions that can assess their feelings, behaviors, and experiences. The exploratory study is prerequisite to the solution of that problem. The development of the wholesome recreational programs and culture for the adolescents is also essential to prevent them from being involved in substance abuse.

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An Energy Efficient Multichannel MAC Protocol for QoS Provisioning in MANETs

  • Kamruzzaman, S.M.;Hamid, Md. Abdul
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.5 no.4
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    • pp.684-702
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    • 2011
  • This paper proposes a TDMA-based multichannel medium access control (MAC) protocol for QoS provisioning in mobile ad hoc networks (MANETs) that enables nodes to transmit their packets in distributed channels. The IEEE 802.11 standard supports multichannel operation at the physical (PHY) layer but its MAC protocol is designed only for a single channel. The single channel MAC protocol does not work well in multichannel environment because of the multichannel hidden terminal problem. Our proposed protocol enables nodes to utilize multiple channels by switching channels dynamically, thus increasing network throughput. Although each node of this protocol is equipped with only a single transceiver but it solves the multichannel hidden terminal problem using temporal synchronization. The proposed energy efficient multichannel MAC (EM-MAC) protocol takes the advantage of both multiple channels and TDMA, and achieves aggressive power savings by allowing nodes that are not involved in communications to go into power saving "sleep mode". We consider the problem of providing QoS guarantee to nodes as well as to maintain the most efficient use of scarce bandwidth resources. Our scheme improves network throughput and lifetime significantly, especially when the network is highly congested. The simulation results show that our proposed scheme successfully exploits multiple channels and significantly improves network performance by providing QoS guarantee in MANETs.

A Study on the Floating OWC Chamber Motion in Waves (부유기 OWC 챔버의 파중 운동해석)

  • 홍도천
    • Journal of Ocean Engineering and Technology
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    • v.16 no.3
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    • pp.19-27
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    • 2002
  • The motion of a floating OWC chamber in waves is studied taking account of fluctuating air pressure in the air chamber. An atmospheric pressure drop occurs across the upper opening of the chamber which causes not only hydrodynamic but also pneumatic added mass and damping forces to the floating chamber. A velocity potential in the water due to the free surface oscillating pressure patch is added to the conventional radiation-diffraction potential problem. the potential problem inside the chamber is formulated by making use of the Green integral equation associated with the Rankine Green function wile the outer problem with the Kelvin Green function. The two integral equations are solved simultaneously by making use of a matching boundary condition at the lower opening of the chamber to the outer water region. The chamber motion in the frequency domain is calculated for various values of parameters related to the atmospheric pressure drop. The present methods can also be sued for the analysis of air-cushion vehicle motion as well as for the design of a floating OWC wave energy absorber.

A Study on the Floating OWC Chamber Motion in Waves (부유식 OWC 챔버의 파중 운동해석)

  • Hong, Do-Chun;Hong, Sa-Young
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2002.05a
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    • pp.191-197
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    • 2002
  • The motion of a floating OWC chamber in waves is studied taking account of fluctuating.air pressure in the air chamber. An atmospheric pressure drop occurs across the upper opening of the chamber which causes not only hydrodynamic but also pneumatic added mass and damping forces to the floating chamber. A velocity potential in the water due to the free surface oscillating pressure patch is added to the conventional radiation-diffraction potential problem. The potential problem inside the chamber is formulated by making use of the Green integral equation associated with the Rankine Green function while the outer problem with the Kelvin Green function. The two integral equations are solved simultaneously by making use of a matching boundary condition at the lower opening of the chamber to the outer water region. The chamber motion in the frequency domain is calculated for various values of parameters related to the atmospheric pressure drop. The present methods can also be used for the analysis of air-cushion vehicle motion as well as for the design oj a floating owe wave energy absorber.

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Implementation of Protein Motif Prediction System Using integrated Motif Resources (모티프 자원 통합을 이용한 단백질 모티프 예측 시스템 구현)

  • Lee, Bum-Ju;Choi, Eun-Sun;Ryu, Keun-Ho
    • The KIPS Transactions:PartD
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    • v.10D no.4
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    • pp.679-688
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    • 2003
  • Motif databases are used in the function and structure prediction of proteins which appear on new and rapid release of raw data from genome sequencing projects. Recently, the frequency of use about these databases increases continuously. However, existing motif databases were developed and extended independently and were integrated mainly by using a web-based cross-reference, thus these databases have a heterogeneous search result problem, a complex query process problem and a duplicate database entry handling problem. Therefore, in this paper, we suppose physical motif resource integration and describe the integrated search method about a family-based protein prediction for solving above these problems. Finally, we estimate our implementation of the motif integration database and prediction system for predicting protein motifs.

A Case Report of Problem Behavior in Adult with Severe Intellectual Disability Treated with the Korean Herbal Medicine Yokukan-san-gami (Yigan-san-jiawei) (성인 중증 지적장애에서의 문제행동에 대한 억간산가미(抑肝散加味) 치험 1례 보고)

  • Choi, Eun-ji;Suh, Hyo-weon;Chung, Sun Yong;Kim, Jong Woo
    • Journal of Oriental Neuropsychiatry
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    • v.28 no.4
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    • pp.341-347
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    • 2017
  • This case report presents a 31-year-old male intellectual disability patient with problem behavior such as food refusal and temper tantrums. He was treated with the Korean traditional herbal medicine (Yokukan-san-gami) continuously for 56 days. The effects of the treatment were measured by the frequency of his problem behavior and the score of the Korean version of Aberrant Behavior Checklist (ABC). After treatment, his challenging behavior became reduced, and his ABC score had been decreased by 24.6%. The findings from this case suggest that the Korean traditional herbal medicine (Yokukan-san) could be effective for challenging behavior in patients with intellectual disabilities.

An interactive and iterative control panel layout

  • 박성준;정의승;조항준
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1994.04a
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    • pp.103-111
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    • 1994
  • An interactive and iterative design method based on the constraint satisfaction problem (CSP) technique was developed to generate an ergonomically sound layout of a control panel. This control panel layout method attempts to incorporate a variety of relevant ergonomic principles and design constraints, and generate an optimal or, at least, a "satisfactory" solution through iterative interactions with the designer. The existing panel design and layout methods are mostly based on the optimization of single objective function formulated to reflect and trade off all ergonomic design objectives which are largely different in their nature. In fact, the problem of seeking an ergonomically sound panel design should be viewed as a multiple objective optimization problem. Furthermore, most of the design objectives should be understood as constraints rather than objectives to be optimized. Hence, a constraint satisfaction approach is proposed in this study as a framework for the panel designer to search through the design decision space effectively and make various design decisions iteratively. In order to apply the constraint satisfaction approach to the panel design procedure, the ergonomic principles such as frequency-of-use, importance, functional grouping, and sequence-of-use are formalized as CSP terms. With this formalization, a prototype system was implemented and applied to panel layout problems. The results clearly showed the effectiveness of the proposed approach since it permits designers to consider and iteratively evaluate various design constraints and ergonomic principles, and, therefore, aids the panel designer to come up with an ergonomically sound control panel layout.

The Analysis of Cipher Padding Problem for Message Recovery Security Function of Honey Encryption (허니암호의 메시지 복구보안 기능을 위한 암호패딩 문제점 분석)

  • Ji, Changhwan;Yoon, Jiwon
    • Journal of KIISE
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    • v.44 no.6
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    • pp.637-642
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    • 2017
  • Honey Encryption (HE) is a technique to overcome the weakness of a brute-force attack of the existing password-based encryption (PBE). By outputting a plausible plaintext even if the wrong key is entered, it provides message recovery security which an attacker can tolerate even if the attacker tries a brute-force attack against a small entropy secret key. However, application of a cipher that requires encryption padding to the HE present a bigger problem than the conventional PBE method. In this paper, we apply a typical block cipher (AES-128) and a stream cipher (A5 / 1) to verify the problem of padding through the analysis of the sentence frequency and we propose a safe operation method of the HE.

Wind induced vibrations of long electrical overhead transmission line spans: a modified approach

  • Verma, Himanshu;Hagedorn, Peter
    • Wind and Structures
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    • v.8 no.2
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    • pp.89-106
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    • 2005
  • For estimating the vortex excited vibrations of overhead transmission lines, the Energy Balance Principle (EBP) is well established for spans damped near the ends. Although it involves radical simplifications, the method is known to give useful estimates of the maximum vibration levels. For very long spans, there often is the need for a large number of in-span fittings, such as in-span Stockbridge dampers, aircraft warning spheres etc. This adds complexity to the problem and makes the energy balance principle in its original form unsuitable. In this paper, a modified version of EBP is described taking into account in-span damping and in particular also aircraft warning spheres. In the first step the complex transcendental eigenvalue problem is solved for the conductor with in-span fittings. With the thus determined complex eigenvalues and eigenfunctions a modified energy balance principle is then used for scaling the amplitudes of vibrations at each resonance frequency. Bending strains are then estimated at the critical points of the conductor. The approach has been used by the authors for studying the influence of in-span Stockbridge dampers and aircraft warning spheres; and for optimizing their positions in the span. The modeling of the aircraft warning sphere is also described in some detail.

Two-Wavelength Phase-Shifting Projection $Moir\acute{e}$ Topography for Measurement of Three-Dimensional Profiles with High Step Discontinuities (고단차 불연속 형상의 3차원 측정을 위한 이중파장 위상천이 영사식 무아레)

  • Kim, Seung-Woo;Oh, Jung-Taek;Jung, Moon-Sik;Choi, Yi-Bae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.23 no.7 s.166
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    • pp.1129-1138
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    • 1999
  • [$Moir\acute{e}$] technique is now being extensively investigated as a fast non-contact means of three-dimensional profile measurement especially for reverse engineering. One problem with $moir\acute{e}$ technique is so called $2\pi$-ambiguity problem that limits the maximum step height difference between two neighboring sampling points to be less than half the equivalent wavelength of $moir\acute{e}$ fringes. In this investigation, a new two-wavelength scheme of projection $moir\acute{e}$ topography is proposed and tested to cope with the $2\pi$-ambiguity problem. Experimental results are discussed to assess the new method in measuring large objects with high step discontinuities.