• IEIE Transactions on Smart Processing and Computing
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• 제1권2호
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• pp.95-105
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• 2012

The widespread implementation of RFID in ubiquitous computing is constrained considerably by privacy and security unreliability of the wireless communication channel. This failure to satisfy the basic, security needs of the technology has a direct impact of the limited computational capability of the tags, which are essential for the implementation of RFID. Because the universal application of RFID means the use of low cost tags, their security is limited to lightweight cryptographic primitives. Therefore, EPCGen2, which is a class of low cost tags, has the enabling properties to support their communication protocols. This means that satisfying the security needs of EPCGen2 could ensure low cost security because EPCGen2 is a class of low cost, passive tags. In that way, a solution to the hindrance of low cost tags lies in the security of EPCGen2. To this effect, many lightweight authentication protocols have been proposed to improve the privacy and security of communication protocols suitable for low cost tags. Although many EPCgen2 compliant protocols have been proposed to ensure the security of low cost tags, the optimum security has not been guaranteed because many protocols are prone to well-known attacks or fall short of acceptable computational load. This paper proposes a remedy protocol to the flyweight RFID authentication protocol proposed by Burmester and Munilla against a desynchronization attack. Based on shared pseudorandom number generator, this protocol provides mutual authentication, anonymity, session unlinkability and forward security in addition to security against a desynchronization attack. The desirable features of this protocol are efficiency and security.

• The Korean Journal of Physiology and Pharmacology
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• 제24권1호
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• pp.39-46
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• 2020

Alzheimer's disease (AD) is the most common neurodegenerative disorder causing dementia worldwide, and is mainly characterized by aggregated β-amyloid (Aβ). Increasing evidence has shown that plant extracts have the potential to delay AD development. The plant sterol β-Sitosterol has a potential role in inhibiting the production of platelet Aβ, suggesting that it may be useful for AD prevention. In the present study, we aimed to investigate the effect and mechanism of β-Sitosterol on deficits in learning and memory in amyloid protein precursor/presenilin 1 (APP/PS1) double transgenic mice. APP/PS1 mice were treated with β-Sitosterol for four weeks, from the age of seven months. Brain Aβ metabolism was evaluated using ELISA and Western blotting. We found that β-Sitosterol treatment can improve spatial learning and recognition memory ability, and reduce plaque load in APP/PS1 mice. β-Sitosterol treatment helped reverse dendritic spine loss in APP/PS1 mice and reversed the decreased hippocampal neuron miniature excitatory postsynaptic current frequency. Our research helps to explain and support the neuroprotective effect of β-Sitosterol, which may offer a novel pharmaceutical agent for the treatment of AD. Taken together, these findings suggest that β-Sitosterol ameliorates memory and learning impairment in APP/PS1 mice and possibly decreases Aβ deposition.

• Earthquakes and Structures
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• 제8권2호
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• pp.305-377
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• 2015

The problem of earthquake induced torsion in buildings is quite old and although it has received a lot of attention in the past several decades, it is still open. This is evident not only from the variability of the pertinent provisions in various modern codes but also from conflicting results debated in the literature. Most of the conducted research on this problem has been based on very simplified, highly idealized models of eccentric one-story systems, with single or double eccentricity and with load bearing elements of the shear beam type, sized only for earthquake action. Initially, elastic models were used but were gradually replaced by inelastic models, since building response under design level earthquakes is expected to be inelastic. Code provisions till today have been based mostly on results from one-story inelastic models or on results from elastic multistory idealizations. In the past decade, however, more accurate multi story inelastic building response has been studied using the well-known and far more accurate plastic hinge model for flexural members. On the basis of such research some interesting conclusions have been drawn, revising older views about the inelastic response of buildings based on one-story simplified model results. The present paper traces these developments and presents new findings that can explain long lasting controversies in this area and at the same time may raise questions about the adequacy of code provisions based on results from questionable models. To organize this review better it was necessary to group the various publications into a number of subtopics and within each subtopic to separate them into smaller groups according to the basic assumptions and/or limitations used. Capacity assessment of irregular buildings and new technologies to control torsional motion have also been included.

• 한국의상디자인학회지
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• 제19권4호
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• pp.105-121
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• 2017

This study determined the reality of how middle school students are doing with their free learning semester and what they think about it. Also, the study looked at how many parts of Home Economics and the area of clothing curriculum are being taken and, especially, how many parts of this curriculum content are being required as free learning semester activities. This study aims to not only develop free learning semester activities according to student demand but also at providing a basic resource that can help activate the area of clothing curriculum in subject of Home Economics. In short: 1) Middle school students are attending activities such as career exploration activities, student selection activities, club activities, arts activities and physical education activities thoroughly through the free learning semester. These mostly take place in school and most of the students were taught by teachers from their own school. 2) The students are aware that the free learning semester's activities are helpful for them. The most helpful part was that it reduces the load they get from the school's exam and also the fact that they can investigate areas in which they are interested. 3) The number of students who have already taken or are taking activities related to Home Economics were 145, which is about 1/3 of the 451 students overall. The area where the most of the activities were held out of those activities related to Home Economics was the domain of food while the clothing curriculum accounted for a very small part compared to it. 4) The study found that need for a clothing curriculum for middle school student free learning semesters was about 2.79 on a scale from 1 to 5. The areas of most interest in this topic were highly related to 'making and mending clothes'.

• 수산해양기술연구
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• 제26권2호
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• pp.111-117
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• 1990

스프링강으로 만든 3가지 크기의 타원형후크에 대하여 만능시험기로 특성시험을 하고, 나팔관을 사용한 통발 자동분리기로 모릿줄의 고달이에 연결된 타원형후크에서 장어통발이 분리되도록 하는 실험을 육상과 해상에서 각각 시행한 경과는 다음과 같다. 1. 직경 3.1mm인 대형의 타원형후크에서 줄의 이탈장력은 60kg 정도이고, 줄을 끼워넣기 위한 손누름 압축력은 6kg 정도이며, 나팔관을 통과장력은 11~15kg 정도였다. 2. 현측 로울러의 앞쪽이나 뒤쪽에 나팔관을 부착한 자동분리기를 사용하여 대형후크에서 통발이 자동으로 분리되도록 하는 육상실험의 결과 양승속도 2~4m/sec에서 분리율은 99%정도였다. 3. 현측 로울러의 후방 2m 정도 되는 곳에 나팔관을 설치하고 대형후크로 해상 시험조업을 한 결과 양승속도 3~4m/sec에서 통발의 분리율은 97%정도였다.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2003년도 추계학술대회 논문집
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• pp.340-345
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• 2003

This study, as a basic study for establishing a influence forecasting/estimating model when drain the deep sea water to the ocean after using it, carried out studies as follows; 1) estimating the amount of river discharge and pollutant loads inflowing into the developing region of deep sea water in East Sea, Korea 2) a field observation of tidal current, vertical distribution of water temperature and salinity, and 3-D numerical experiment of tidal current to analysis physical oceanographic status. The amount of river discharge flowing into the study area was estimated about $462.6{times}10^{3}m^{3}/day$ of daily mean in 2002 year. annual mean pollutant load of COD, TN and TP were estimated 7.02 ton-COD/day, 4.06 ton-TN/day and 0.39 ton/day, respectively. Field observation of tidal current results usually show about $20{\sim}40cm/sec$ of current velocity at the surface layer, it indicated a tendency that the current velocity decreases under 20cm/sec as the water depth increases. We could find a stratification within approximately the depth of 30m in field observation area, and the depth increases. We could find a stratification within approximately the depth of 30m in field observation area, and the differences of water temperature and salinity between the surface layer and bottom layer were about $18^{\circ}C$ and 0.8 psu, respectively. On the other hand, we found that there was a definite as the water mass of deep sea water about 34 psu of salinity.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 봄 학술발표회 논문집
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• pp.395-402
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• 2000

Recently, the deep excavations have been peformed to utilize the under ground space. As the ground excavation is deeper, the damage of the adjacent structure and the ground occurs frequently. The analysis of the retaining structures is necessary to the safety of the excavation works. There are many methods such as elasto-plastic, FEM, and FDM to analyze the displacement of the retaining structure. The elasto-plastic method is generally used in practice. In this thesis, GEBA-1 program by the Nakamura-Nakajawa elasto-plastic method was developed. The program for Windows was used the Visual Basic 6.0, and the Main of the program consists of three subroutines, SUB1, SUB2, and SUB3. The lateral displacement of the wall was analyzed by the developed program GEBA-1, SUNEX, and EXCAD, and compared with the measured displacement by the Inclinometer(at three excavation work sites). The excavation method of each site is braced retaining wall using H-pile. Each excavation depth is 14m, 14m, or 8.2m. The results of the analyses are the followings ① In the multi-layer soil, the lateral displacement by the GEBA-1 and EXCAD which is considering the distribution of the strut load is equal to the measured displacement. Elasto-plasto programs can't consider the change of the ground water in clay. Therefore, the analysis displacement was expected only 20% of the measured wall displacement. ③ At the final excavation step, the maximum lateral displacement of analysis and field occurred 7∼18m at the 85∼92% of the excavation depth. ④ The maximum lateral displacement in clay, as 50mm, occurred on the ground surface.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2008년도 학술대회 1부
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• pp.688-692
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• 2008

3차원 아바타 시스템에서 아이템들은 아비타의 체형마다 맞춰서 제작하여야 한다. 이러한 제작방식은 사업적인 측면에서 불리한점이 클 뿐만 아니라, 서비스하는 아바타의 체형, 종류와 같은 다양성 측면에서도 소비자의 욕구를 만족하기 어렵다. 다양한 체형의 아비타를 서비스하기 위해 제작해야 할 작업량은 기하급수적으로 늘어날 수밖에 없다. 본 연구는 아바타의 제형을 최소한의 데이터 제작으로 표현가능 하도록 메쉬모핑(mesh morphing) 기법을 활용한 3D 아바타 체형변형방법에 관한 것이다. 아바타의 기본제형과 변형될 체형을 토대로 실시간으로 표현할 수 있는 중간체형을 생성하는 방법과 기본체형에 맞게 제작된 의상, 헤어스타일, 신발 등 아바타 아이템 들을 중간체형에 맞도록 자동으로 변형하는 방법을 소개한다. 제시한 방법을 이용하면, 새로운 체형의 아바타를 도입하더라도 기 제작된 아이템들의 추가 제작 없이 새로운 체형에 맞는 아이템을 서비스할 수 있음을 보여준다. 또한 새로운 체형의 표현 방법이 실시간으로 적용할 수 있는 방직임을 보여준다.

• 한국건축시공학회지
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• 제2권2호
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• pp.129-134
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• 2002

The strength and durability of concrete are affected by various factors such as the quality of material, mixing ratio, construction, the method of cure, time elapsed. the condition of test and etc., it is very difficult to pre-estimate the strength of concrete with the use of experimental specimen. The domestic standard of specimen cylindrical type and its sizes are both l0cm$\times$20cm and 15cm$\times$30cm, which are prescribed in KS F2405, and the loading speed is prescribed to test with 2~3kgf/$\textrm{cm}^2$ per second. The loading speed should have great effect on the compressive strength, but in reality in the construction site sometimes the loading speed is applied so dubiously that the value of the compressive strength can be unreliable. And the cross sectional area of a specimen should be level and smooth, otherwise it can be broken at a lower stress than the real strength through the eccentric or intensive working of the load. Capping should be carried out in order to measure the strength correctly. And used for capping are various materials such as capping compound, cement glue, plaster, mechanical grinding and etc. In this study, therefore, I have carried out an experiment on the relationship among the loading speed, the ratio of height to diameter of specimen, the method of capping, and the compressive strength, for the efficient quality control of concrete structures. So this study has been purposed to provide some basic data that can be used effectively at construction sites.

• 대한토목학회논문집
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• 제31권6D호
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• pp.811-818
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• 2011

굴삭기는 삽날(shovel)을 이용해서 토공작업을 하는 장비로 분류되어 있으나, 실질적으로는 굴착을 한 후 물체를 인양하여 옮기는 작업에 이용되고 있다. 이러한 관점에서 인양력은 굴삭기의 주요성능으로 분류될 필요가 있으며, 정확한 성능을 제공할 필요가 있다. 하지만 국내 현실은 아직 이러한 요구를 충족시켜 주지 못하고 있다. 본 연구에서는 1) 외국의 굴삭기 인양력에 대한 조사를 실시하여 국내 도입을 위한 기초자료로 활용하고자 하였다. 2) 인양력에 대한 정보 없이 국내에서 사용중인 굴삭기에 적용할 수 있는 인양력 산정방법을 제안하고 이를 검증해 보았다. 3) 인양 가능한 구간을 인양안전구간과 인양주의구간으로 나누어 제공할 것을 제안하였다. 본 연구에서 제시한 굴삭기의 인양력 정보와 인양구간에 관한 정보는 작업계획 및 안전관리업무에 객관적이고 실질적인 기저정보로서 활용될 수 있을 것이다.