• 건축역사연구
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• 제4권1호
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• pp.79-92
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• 1995

The study is about the process of modernization of conventional rural houses in Kyung-gi province. It alms to identify the pattern of change, particularly focusing on the changes of the site plan and plan. The site of study is Samga Village, in YongIn County, near Seoul. The study discusses the process of modernization during the three decades from 1960 to 1980. The basic information was obtained through field research and site analysis, and the study relies predominatly on observational and statistical analysis. Four developmental stages can be clearly identified which are ; (1) Traditional type, (2)Modified-traditional type, (3) Saemaul type, and (4) The type of urban houses. The analysis was done through identification of changing site plan and plan. It is interesting to note that the changes of these elements show a certain pattern of sequential steps which also can be classified according to the four developmental stages mentioned above. The pattern of site design was consistantly maintained while plan and building system became very different However, the process of modernization of Korean rural houses was the process of producing a certain type of architecture that is not universal but uniquely Korean.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회 논문집(II)
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• pp.961-966
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• 2000

It is difficult to change or remedy concrete structure after hardened. It is usual to evaluate the quality of hardened concrete using several test method. This study was performed to make fundamental data that could be used to evaluate the quality of hardened concrete. This study is to estimate mix proportion of hardened concrete. Each elements of concrete needed different estimation methods. First, the cement that handled by the most important compounds measured by XRF(X-ray fluorecence) machine with scanning Ca-K${\alpha}$. Second, the coarse aggregate that divided by maximum size measured by the area comparison method that starts from the assumption of uniform distribution. Third, the fine aggregate measured by the weight comparison method that needs several prerequsite constants which concerned cement hydration reaction. Fourth, the water content would be estimated by expert system that has data base of design data, the contents of above estimation results, the characteristics of concrete strength. As the result of the above research, some conclusions are as follows. The cement estimation method resulted by reliability of mean 96.7%, standard deviation 3.92. The area comparison method resulted by reliability of mean 95.3%, standard deviation 2.08. The weight comparison method resulted by reliability of mean 93.3%, standard deviation 3.35.

• 대한교통학회지
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• 제23권5호
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• pp.35-45
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• 2005

자동 과속 단속 시스템은 중요한 교통사고 예방 대책의 하나이다. 운전자는 자동과속단속시스템 설치 지점 부근에서 속도를 감속하고 설치지점 통과 후 다시 가속한다. 따라서 단속의 목적을 둔 과속단속시스템은 충분한 안전 효과를 발휘하는데 한계가 있으며, 속도 관리 개념의 설치 방안이 마련될 필요가 있다 본 연구는 연속된 도로 구간을 주행하는 운전자의 주행속도 변화를 일정 범주 내로 유지시키는 도로 설계 일관성 개념을 과속단속시스템의 설치위치 선정에 적용하였다. 또한 과속단속시스템도 도로 곡선부 등 선형 요소와 마찬가지로 운전자의 주행속도를 변화시키는 설계 요소의 하나로 간주하고, 설계 일관성 개념 및 평가기준을 동일하게 적용한 설치 방안을 제안하였다.

• 열처리공학회지
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• 제34권2호
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• pp.53-59
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• 2021

Due to high specific strength and low density, AZ series magnesium alloys have been receiving high interest as a lightweight material. However, their industrial application is limited due to the phenomenon that the strength decreases at elevated temperature by the occurrence of softening effect because of the Mg17Al12 phase decomposition. To solve this problem, many research were conducted to increase the high-temperature strength by forming a thermal stable second-phase component by adding new elements to the AZ magnesium. Especially, adding Ca to AZ magnesium has been reported that Ca forms the new second-phase. However, studies about the analysis of decomposition or precipitation temperature, formation composition, and components to understand the formation behavior of these precipitated phases are still insufficient. Therefore, the effect of Ca addition to AZ61 on the phase change and microstructure of the alloy during annealing was investigated. As a result of analysis of the initial and heat-treated specimen, AZ61 formed α-Mg matrix and precipitated phase of Mg17Al12, and AZX611 formed one more type of precipitated phase, Al2Ca. Also, Al2Ca was thermal stable at high temperatures. And after annealing, the laves phase was decomposed to under 10 ㎛ size and distributed in matrix.

• 한국전기전자재료학회논문지
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• 제29권3호
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• pp.175-180
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• 2016

In this study, we proposed an optical compensation method to improve the symmetricity of contrast ratio for wide viewing angle IPS (in-plane switching) LCD. First, the phase retardation depending on the thickness of compensation film is calculated, and then the phase change is presented at the $Poincar{\acute{e}}$ sphere. The phase retardation and the polarization state of the light passing through the optical elements are caculated by using the EJMM (extended Jones matrix method). In addition, the transmittance and the contrast countour are also calculated by using the Berremann's $4{\times}4$ matrix method. The simulation is carried out for a IPS LC cell with positive A/C/A compensation film. From the standard deviation of the contrast ratio, we confirmed the symmetricity at each viewing angle is inversely proportional to the standard deviation and calculated the optimum design condition of the uniaxial compensation film for the IPS LCD.

• 한국주거학회논문집
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• 제23권2호
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• pp.1-14
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• 2012

In Korea, apartment complexes are built according to the social strata for which they are intended to house, thus the buildings tend to separate society both physically and even visually. Because of the sense of social exclusion this has caused the government has conceived a plan to develop a "social-mix" apartment complex master plan. Perhaps the foremost example of this type of plan is the Seoul Eunpyeong New Town. This study examines how resident's perception of the social mix plan has evolved, and also attempts to better understand the effectiveness of the government's attempt at social integration. The result shows that the perception of social-mix housing has improved after residents moved into the Eunpyeong New Town and that people responded positively to the concept of actually mixing residents socially. From the result, we can see that the visually unexposed environmental elements of rental housing and socials exclusion which was felt in the past has been reduced to a certain extent. However, residents living in solid-lot apartments have a negative reaction to social mixing especially when they are in the same building. Therefore, to achieve better social integration in a socially-mixed apartment complex, we need now to change the perception toward socially mixed housing among the residents living in solid-lot apartment buildings.

• 한국공간구조학회논문집
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• 제16권1호
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• pp.53-64
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• 2016

Solar power is being spotlighted recently as a new energy source due to environmental problems and applications of solar power to curved structures are increasing. Solar panels installed on curved surfaces have different efficiencies depending on its position and the efficient positioning of solar panels plays a critical role in the design of solar power generation systems. In this study, the changing characteristics of solar irradiance were analyzed for hemispherical dome with a large curvature and the positioning of solar panels that can efficiently utilize solar energy was investigated. With an icosahedron-based hemispherical dome consisting of triangular elements as target model, a program for calculating solar irradiance using a normal vector of the solar module on each face was developed. Furthermore, the change of solar irradiance according to the sun's path was analyzed by time and season, and its effects on shades were also examined. From the analysis results, the effective positioning could be determined on the basis of the efficiency of the solar panels installed on the dome surfaces on solar irradiance.

• 디지털산업정보학회논문지
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• 제15권2호
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• pp.43-52
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• 2019

The recent technological developments of smart devices, multiple services are provided to enhance the users' quality of life including smart city, smart energy, smart car, smart healthcare, smart home, and so on. Academia and industries try to provide the users with convenient services upon seamless technological research and developments. Also, whenever and wherever a variety of services can be used without any limitation on the place and time upon connecting with different types of devices. However, security weaknesses due to integrations of multiple technological elements have been detected resulting in the leakage of user information, account hacking, and privacy leakage, threats to people's lives by device operation have been raised. In this paper, safer communication framework is suggested by device control and user authentication in the mobile network environment. After implementations of registration and authentication processes by users and devices, safe communication protocol is designed based on this. Also, renewal process is designed according to the safe control of the device. In the performance evaluation, safety was analyzed on the attack of protocol change weakness occurred in the existing system, service halt, data leakage, illegal operation control of message, and so on, which confirmed the enhanced speed approximately by 8% and 23% in the communication and verification parts, respectively, compared to the existing system.

• 전기학회논문지
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• 제62권10호
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• pp.1403-1407
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• 2013

This paper presents the method to calculate the motor parameters considering skew in EPS Interior Permanent Magnet Synchronous Motor (IPMSM). The skew is applied to stator or rotor by general technology used for design of reducing noise and vibration in motor. The characteristics analysis of motor including the skew is mostly used by 3D Finite Element Analysis (FEA), though, this analysis is a very time-consuming to perform. Besides, The reliability lacks due to the considerable change of motor characteristics according to the number of elements in 3D FEA. However, analysis time and effort can be saved by characteristic analysis considering skew using 2D FEA. Therefore, in this paper, a quick and accurate method for the calculations of motor parameters considering skew is suggested. The proposed method is verified by the comparison of calculated and experimental results.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.690-695
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• 2005

Flexible circular cantilever beams when excited externally introduce a lot of dynamic characteristics. The non-linear elements that these flexible beams develop include non-linearity due to inertia terms, spring, and damping. They show different characteristics of motion from each other. In the modes of lower order, the non-linearity due to spring is prevalent, while the non-linearity due to inertia Is prevalent in the modes of higher order. To analyze these effects the non-linear phenomena are analyzed experimentally. When the response characteristics of non-linear vibration are analyzed using autospectrum, it is possible to analyze the subharmonic and superharmonic mot ion by comparison. The phase change is analyzed using the method of phase portrait and the non-linear characteristics of response characteristics that are developed in flexible structures can be predicted and applied to the stage of design.