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        검색결과 121

        41.
        2016.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        육방정계 우르자이츠형의 산화아연은 n형 반도체로써 3.37 eV의 넓은 밴드갭 에너지와 60 meV의 큰 엑시톤 바인딩 에너지를 가진 물질이다. 가스센서, 발광 다이오드, 염료 감응 태양 전지, 염 료오염의 분해 등의 넓은 범위에서 활용이 가능하다. 합성 시 마이크로파 수열합성법을 사용하게 되면 높은 수율, 빠른 반응속도, 에너지 절약의 장점이 있다. 아민첨가제는 수산이온 생성 및 킬레이트 효과 로 인해 산화아연 입자 형상을 조정하는 역할을 한다. 본 논문에서는 전구체로는 질산아연육수화물을 사 용하였고, 형상조정제로는 에탄올아민, 에틸렌디아민, 디에틸렌트리아민, 헥사메틸렌테트라민을 사용하였 다. 수산화소듐을 사용하여 용액을 pH 11로 조정하였다. 합성된 산화아연은 별모양, 막대형, 꽃모양, 원 추형의 다양한 형상을 확인할 수 있었다. 아민첨가제에 의한 물리·화학적 특성과 광학적 특성을 분석하 기 위해 XRD, SEM, EDS, FT-IR, UV-vis 스펙트럼, PL 스펙트럼을 사용하였다.
        4,000원
        42.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This research is to investigate the performance analysis of methanol fuel cell for flow channel with four different types of the channel (Serpentine I, II, Inter-digitated, Parallel) in the fuel cell stack. Velocity, pressure, temperature and density distributions of fluid over the flow domain of the flow channel are numerically calculated for the optimum design of flow channel with uniform inlet velocity. According to better water discharge and mutual gas reaction with low pressure drop and high density difference between inlet and outlet in the flow channel, Serpentine I type is of highest performance of the flow channel shapes in the present methanol fuel cell models.
        4,000원
        44.
        2015.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present study analyzed data from the 3D measurement of the feet of men aged over 20 years residing in the capital region as part of the 6th Anthropometry of Size Korea. To analyze the characteristics of the foot shapes of young men aged 20~39 years and middle-aged/elderly men aged 40~69 years by age and by type, a cluster analysis was conducted using the factors derived through the factor analysis as independent variables. The results of the study that analyzed the characteristics of foot shapes by type according to differences in age were as follows. First, through the analysis of the characteristics of the foot shapes of young men by type, five factors were extracted, and the foot shapes were classified into three types: Type 1 (short and flat), Type 2 (thick), and Type 3 (long and wide). Second, through the analysis of the characteristics of the foot shapes of middle-aged/elderly men by type, six factors were extracted, and the foot shapes were classified into four types: Type 1 (short and regular), Type 2 (flat), Type 3 (thick), and Type 4 (long and regular). The results of the present study are expected to serve as basic data for the design of shoes by age and foot type.
        4,300원
        45.
        2015.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study analyzed the body-type characteristics of 340 old-aged obese women that had been on the rise as a part of efforts to activate the silver clothing industry. The subjects were in the age range of 60-79 and met some obesity requirements, including a Rohrer Index of 1.6 or higher, a BMI of 25 or higher, and a WHR of 0.85 or higher. Old-aged obese women showed increased thickness of the torso with age, which suggests that they revealed the characteristics of regardless of gender. In other words, they became bigger in the waist and abdomen, shorter in height, slimmer in the lower body, and thicker in the torso. There are three types of obesity: Type 1 is lower-body obesity with a higher degree of obesity in the abdomen than the upper body. Type 2 is abdominal obesity with a higher degree of obesity in the upper body than in the lower body. Type 3 is whole-body obesity with balanced obesity of the whole body. As for changes to the types of obesity according to age, those who are in their sixties usually fall into the categories of upper-body and whole-body obesity, and those who are in their seventies are much more concentrated in the categories of abdominal obesity and upper-body obesity with a decreased percentage of whole-body obesity. It is apparent that the percentage of abdominal and upper-body obesity rises with age due to fat accumulation in the abdomen.
        4,500원
        46.
        2015.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 소형어선 및 예인선단의 해양사고 사례를 통해 선박의 규정된 등화 및 형상물로 오인할 수 있거나 그들의 특성식별을 방해하는 등화 및 형상물 또는 적절한 경계(警戒)를 방해하는 등화 및 형상물의 문제점을 살펴보았다. 그리고 다음과 같이 선박의 등화 및 형상물에 관한 규칙을 규정하고 있는 국내법의 개정 필요성을 제시하고자 한다. 먼저「총톤수 10톤 미만 소형어선의 구조 및 설비기준」은 소형어선이 「국제해상충돌예방규칙」제26조 및「해사안전법」제84조에서 규정하고 있는 “어로에 종사하고 있는 선박”이 표시하여야 하는 등화 및 형상물을 비치하도록 개정하여야 한다. 둘째 소형어선의 항해등 및 레이더반사기에 관한 면제 규칙을 규정하고 있는「어선설비기준」은「해사안전법」제20조의 규정을 충족하도록 개정하여야 한다. 셋째 「해사안전법」제2조에서 규정하고 있는 “예인선열”의 정의는 「국제해상충돌예방규칙」제24조의 규정을 충족하도록 개정하여야 한다. 또한 모든 항해사에게 해양사고 예방을 위하여 적절한 등화 및 형상물 표시의 중요성을 강조하고자 한다.
        4,000원
        47.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the embedded depth of guardrail posts through 3-D soil material model and carried out evaluation of the dynamic performance of guard rail. In order to calculate for embedded depth of sloping ground, displacement of guardrail posts is analyzed according to the embedded depth of experiment variables. Through the static test of guardrail posts, the maximum deflection was found to decrease the interval. By performing the dynamic test using the Bogie Car, that is confirmed the elastic modulus of the soil occuring the maximum deflection. Guardrail posts is considered to need for further reinforcement in the larger slope than the plains. This study researched about maximum displacement and deviation velocity through dynamic performance of guardrail system and conducted analysis about protection performance evaluation of passenger.
        4,000원
        48.
        2015.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This research is to numerically investigate the flow analysis of thermopneumatic micropump with three different thicknesses of PDMS membrane in micropump owing to the thermal expansion with uniform heat flux in the PDMS membrane. Velocity, temperature distributions and flow rates over the flow domain with different membrane thicknesses in the micropump are numerically calculated for the performance evaluation of pressure increase in micropump with uniform inlet velocity and temperature. According to the calculations of local maximum velocity at outlet, higher thickness of PDMS membrane(500μm) give larger local velocity in the micropump and maximum local velocity occurred at the center of the micropump with respect to the axial direction.
        4,000원
        49.
        2015.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        풍력발전 타워는 높은 세장비를 갖는 형상으로 인해 바람에 의해 발생하는 횡하중에 취약한 구조를 가지고 있기 때문에 바람은 풍력발전 타워를 설계하는데 있어서 중요한 설계요소 중 하나라고 할 수 있다. 본 논문에서는 타워 운송 편의성 향상을 위해 설계된 8각 및 6각 단면형상을 가지는 조립식 강관 타워 및 일반 원형 강관 타워의 일정 높이 이상에서부터 4개의 작은 기둥으로 분리되는 형상을 가지는 멀티기둥 강관 타워에 대한 2차원 단면모형 풍동실험과 3차원 모형 풍동실험을 수행하여 각 형상별 풍력계수를 산정하여 그 특성을 비교하였다. 또한 풍동실험 축소모형에 대한 CFD 해석을 수행하여 산정된 풍력계수값의 신뢰성을 확인하였으며, 마지막으로 실제스케일 풍력타워에 대한 CFD 해석을 수행하여 각 형상별 특성을 분석하였다.
        4,000원
        50.
        2014.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This research is to investigate the performance analysis of cooling fan of the IT and electronic device with two different blade types and three different blade numbers of the cooling fan. Velocity, and temperature distributions of fluid over the flow domain of the flow channel are numerically calculated for the optimum design of flow channel with uniform inlet velocity. According to the calculations of convective heat transfer coefficient between blade and atmosphere in the flow domain, case 2 with 6 blases type shows highest performance of the cooling fan shapes in the present cooling fan model considering manufacturing process and cost
        4,000원
        51.
        2014.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES: This paper evaluates, using LS/DYNA-3D software, the vehicle impact performance of flexible barriers made of steel WBeam supported by four different types of post configurations. These types include circular post, H-shape post, C-shape post, and square post. METHODS : The post-soil interaction has been investigated according to different impact angles. For this purpose, energy absorption, maximum displacements of post and rail, and occupant risk index of THIV have been compared each other. The three dimensional soil material model, instead of the conventional spring model based on Winkler and p-y curve, has been used to increase the correctness of computational model. RESULTS: It is noted the crash energy absorption has been increased with respect to the increase of impact angle. CONCLUSIONS : In particular, a post with open section(H-shape, C-shape) shows the greater crash energy absorption capability as compared with a post with closed section under the same level of impact conditions.
        4,000원
        52.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This research is to investigate the performance analysis of fuel cell for flow channel with four different types of the channel (Serpentine I, II, Inter-digitated, Parallel) in the fuel cell stack. Velocity, pressure. and temperature distributions of fluid over the flow domain of the flow channel are numerically calculated for the optimum design of flow channel with unifrom inlet velocity. According to the calculations of low pressure drop between inlet and outlet in the flow channel, Serpentine I type is of highest performance of the flow channel shapes in the present fuel cell model.
        4,000원
        53.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Base Balance Technique은 건축물의 하중과 변위 및 가속도와 같은 응답들을 구하기 위한 기본적인 풍동실험기법으로 사용되어 왔다. 이 기법은 선형적인 형상함수의 내제된 가정으로 수행함으로써, 밑면 전도모멘트로 일반화된 하중을 추정할 수 있다. 그러나 초고층건물은 다수의 풍방향진동에 대한 형상함수들을 가지고 있다. 본래의 초고층건물의 기본적인 형상함수는 선형적이지 않으므로 풍동실험이나 선형적인 해석의 결과로부터 약간의 조정이 필요하다. 본 연구에서는 풍동실험의 데이터를 이용하여 풍방향응답의 보정계수를 제안한다. 그리고 건물의 높이와 너비, 건물주기 등으로부터 보정계수의 요인들을 이해할 수 있다.
        4,000원
        54.
        2014.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This research is to investigate the performance analysis of turbine for power generation with three different numbers of the nozzle vane in the turbine. Velocity, pressure. and temperature distributions of fluid over the flow domain of the turbine are numerically calculated for the optimum design of nozzle with two different rotational speeds of the turbine blade (1000 and 1500 RPM). Ultimately, the energy-efficient and maximum power-generated shape of the nozzle vane are determined through three different maximum Mach number of the flow with three shapes of the nozzle vane (10, 18, and 24 EA).
        4,000원
        55.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The circular hollow section is usually used for member of main frame to carry the external load in single layer lattice dome. But, the H-shaped section may be used for member of main frame since it is convenient for attaching roof panels. Single layer lattice domes have various buckling characteristics, such as the overall buckling, the member buckling, and nodal buckling. The purpose of this study is to compare buckling characteristics of single-layer lattice domes in which the H-shaped steel section as the existing domestically-produced structural steel is used as main frames to those of domes in which a circular hollow section is used as main frames.
        4,000원
        56.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본고는 한중 동형 한자어의 공기 관계 비교를 통해 중국인 학습자의 한국어 어 휘 습득에 도움이 되고자 하는데 목적이 있다. 중국어 상용 어휘가 중국인의 인지 표현의 기초가 되므로 본고에서는 중국어 상용 어휘를 기준으로 한국어 동형 한자어를 수집하였으며, 먼저 사전적 의미를 기준으로 ‘동형동의, 동형유의, 동형이의’로 나누고, 다시 결합 어휘와 결합 구조가 일치하는지에 따라 분류하여 유형을 제시하였다. 기존의 연구에서는 한자어의 형태와 의미에 주로 의존하여 비교를 한 반면, 본 고에서는 한자어가 주로 결합하는 어휘와 결합 관계를 비교하여 한국어 학습에 더욱 실질적이고 유용한 정보를 제공하고자 하였다
        6,900원
        57.
        2012.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES: This paper evaluates, using LS/DYNA-3D software, the vehicle impact performance of flexible barriers made of steel WBeam supported by four different types of post configurations. These types include circular post, H-shape post, C-shape post, and square post. METHODS : The post-soil interaction has been investigated according to different impact angles. For this purpose, energy absorption, maximum displacements of post and rail, and occupant risk index of THIV have been compared each other. The three dimensional soil material model, instead of the conventional spring model based on Winkler and p-y curve, has been used to increase the correctness of computational model. RESULTS: It is noted the crash energy absorption has been increased with respect to the increase of impact angle. CONCLUSIONS : In particular, a post with open section(H-shape, C-shape) shows the greater crash energy absorption capability as compared with a post with closed section under the same level of impact conditions.
        4,000원
        58.
        2012.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        One of the main problems concerning the shallow seismic survey is how to generate high frequency signals with large amplitudes using small seismic sources. If one could focus the seismic energy in the direction of the survey line, it will be much helpful in identifying the first break. In this research, we have used hammer as an impulsive source and compared the signal powers generated by different shapes of the hammer plates: circular, square, and rectangular. The experiment was conducted by calculating the power spectral density function to compare the frequency spectrum and signal power. In the direction perpendicular to the long side of the rectangular plate, the largest seismic energy with the highest frequency was achieved even with the same weights of hammer plates. Our conclusion is that it is more efficient to use a rectangular plate than a circular (or square) one when conducting a 2-D shallow seismic survey.
        4,000원
        60.
        2012.08 구독 인증기관·개인회원 무료
        The article states that the writing style determines the forms ofChinese Characters during the process in shaping the characters by analyzing the Characters both in Pre-Qin Days and in Qin Dynasty. In other words, the way of writing influences the result of writing------ the forms of Chinese character directly, moreover, any kind of change in characters’ evolution stems from the slight difference from the previous writing style. Characters are presented by using writing, characters on Bamboo or Wood strips in Qin Dynasty are kept more in the inking words in the early forms of Chinese characters; meanwhile , writing style in Qin Dynasty is a transitional form in the change from seal script to clerical script; at the same time, it includes both the writing motivation of seal script and other writing styles, such as, clerical script, running script and cursive script in the following periods and conceives rich connotation in writing styles. So, we know that , to some extent, the writing style can restrict or improve the process of characters’ evolution by researching the writing styles’ influence on the following characters’ shape. And as an internal factor, it is writing style itself that influences the Chinese character’s shapes. In this way, we push the traditional static research of forms of joining different parts to form the Chinese characters and that of changing rules of different parts in Chinese characters to the dynamic level in Chinese characters’ research.
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