• Spatial Information Research
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• 제12권2호
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• pp.165-179
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• 2004

무선인터넷의 보급이 확대되면서 GIS 분야에서도 모바일기기를 이용한 애플리케이션과 서비스에 대한 관심이 커져가고 있으며, 한국 무선인터넷 표준화 포럼에서는 무선인터넷을 위한 모바일 플랫폼의 표준과 함께 휴대단말기를 이용한 지도서비스의 기술규격을 제정해오고 있다. 이 연구는 무선인터넷 환경에서 지도서비스를 중개하는 매핑 미들웨어의 선도적 모델을 제시하는 것을 목적으로 하며, 특히 일반 지도서버와의 상호운용에 초점을 둔다. 이 연구에서는 기존의 유선인터넷 환경에서 사용되던 일반 지도서버들을 무선인터넷 환경에 적용하는 방법을 개발하며, 이를 위해 각기 상이한 운용환경을 가진 지도서버들의 요청/응답 구조와 전송 매개변수를 분석함으로써 매핑 미들웨어가 지도서버의 기능을 십분 활용하도록 한다. 이 연구에서 개발한 매핑미들웨어는 .NET 기반의 XML 웹서비스로 구성되며, 이미지 압축을 통한 데이터 경량화 처리모듈과, 단계구분도, 심볼지도, 차트지도, 조건검색지도 등을 위한 지도표현 처리모듈을 포함한다. 이 연구에서 개발한 매핑 미들웨어는 휴대폰이나 PDA와 같은 모바일 클라이언트와 일반 지도서버 사이의 중개역할을 담당하며, .NET클라이언트와 Java 클라이언트 모두를 지원할 수 있다. 또한, 컴포넌트 방식의 상호운용에 의해 기존의 일반 지도서버뿐만 아니라 향후의 무선인터넷 전용 지도서버와도 연동될 수 있는 확장성을 가진다.

• International Journal of Concrete Structures and Materials
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• 제6권2호
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• pp.65-78
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• 2012

An experimental study was carried out to evaluate fresh properties of a moderately high-strength (high-flowing) self-compacting concrete (SCC) and to investigate shear behavior and performance of deep beams made with SCC. Fresh and hardened properties of normal concrete (NC) and SCC were evaluated. The workability and compacting ability were observed based on casting time and number of surface cavities, respectively. Four-point loading tests on four deep beams (two made with SCC and two with NC) were then conducted to investigate their shear behavior and performance. Shear behavior and performance of beams having two different web reinforcements in shear were systematically investigated in terms of crack pattern, failure mode, and load-deflection response. It was found from the tests that the SCC specimen having a normal shear reinforcement condition exhibited a slightly higher load carrying capacity than the corresponding NC specimen, while the SCC specimen having congested shear reinforcement condition showed a similar load carrying capacity to the corresponding NC specimen. In addition, a comparative study between the present experimental results and theoretical results in accordance with ACI 318 (Building Code Requirements for Reinforced Concrete (ACI 318-89) and Commentary-ACI 318R-89, 1999), Hsu-Mau's explicit method (Hsu, Cem Concr Compos 20:419-435, 1998; Mau and Hsu, Struct J Am Concr Inst 86:516-523, 1989) and strut-and-tie model suggested by Uribe and Alcocer (2002) based on ACI 318 Appendix A (2008) was carried out to assess the applicability of the aforementioned methods to predict the shear strength of SCC specimens.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 봄 학술발표회 논문집
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• pp.173-182
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• 2000

To find axial and lateral responses of impact-driven H piles in embankment(SM), the H piles are instrumented with electric strain gages, dynamic load test is performed during driving, and then the damage of strain gages is checked simultaneously. Axially and laterally static load tests are performed on the same piles after one to nine days as well. Then load-settlement behavior is measured. Furthermore, to find the set-up effect in H pile, No. 4, 16, 26, and R6 piles are restriked about 1, 2, and 14 days after driving. As results, ram height and pile capacity obtained from impact driving control method become 80cm and 210.3∼242.3ton, respectively. At 15 days after driving, allowable bearing capacity by CAPWAP analysis, which 2.5 of the factor of safety is applied for ultimate bearing capacity, increases 10.8%. Ultimate bearing capacity obtained from axially static load test is 306∼338ton. This capacity is 68.5∼75.7% at yield force of pile material and is 4∼4.5 times of design load. Allowable bearing capacity using 2 of the factor of safety is 153∼169ton. Initial stiffness response of the pile is 27.5ton/mm. As the lateral load increases, the horizontal load-settlement behaves linearly to which the lateral load reaches up to 17ton. This reason is filled with sand in the cavity formed between flange and web during pile driving. As the result of reading with electric strain gages, flange material of pile is yielded at 19ton in horizontal load. Thus allowable load of this pile material is 9.5ton when the factor of safety is 2.0. Allowable lateral displacement of this pile corresponding to this load is 23∼36mm in embankment.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2017년도 춘계학술발표대회
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• pp.661-664
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• 2017

Recently, during disasters occurrence, dealing with emergencies has been handled well by the early transmission of disaster relating notifications on social media networks (e.g., Twitter or Facebook). Intuitively, with their characteristics (e.g., real-time, mobility) and big communities whose users could be regarded as volunteers, social networks are proved to be a crucial role for disasters response. However, the amount of data transmitted during disasters is an obstacle for filtering informative messages; because the messages are diversity, large and very noise. This large volume of data could be seen as Social Big Data (SBD). In this paper, we proposed a big data platform for collecting and analyzing disasters' data from SBD. Firstly, we designed a collecting module; which could rapidly extract disasters' information from the Twitter; by big data frameworks supporting streaming data on distributed system; such as Kafka and Spark. Secondly, we developed an analyzing module which learned from SBD to distinguish the useful information from the irrelevant one. Finally, we also designed a real-time visualization on the web interface for displaying the results of analysis phase. To show the viability of our platform, we conducted experiments of the collecting and analyzing phases in 10 days for both real-time and historical tweets, which were about disasters happened in South Korea. The results prove that our big data platform could be applied to disaster information based systems, by providing a huge relevant data; which can be used for inferring affected regions and victims in disaster situations, from 21.000 collected tweets.

• 한국한의학연구원논문집
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• 제17권3호
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• pp.77-85
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• 2011

Objectives : The purpose of this study was to develop a simulator which can analyze the anti-inflammatory effects of medical herbs based on e-cell concerning p38 MAPK signal pathway. Methods : We collected data concerning medical herbs with anti-inflammatory effects and the active compounds to provide as a fundamental databse and to validate the newly developed algorithm. At this time, we used the target database as pubmed and gathered the data by data mining tool, pathway studio. Also we have developed the web-based search system for confirming database related to anti-inflammation. We researched the mechanism of actions of proteins in p38 MAPK signal pathway when active compound has been inserted into the network. We reduced total network into TAK-MKK3-p38 and made the two types of mathematical model about active compounds' interaction. Results & Conclusion : We constructed the database which have 69 cases of medical herbs, 71 cases of active compounds, about 8,000 cases of URL(Uniform Resource Locator) related to papers and reports. We designed the ordinary differential equations for response of TAK, MKK3, p38 in e-cell's cytosol and nucleus. We used this formular as measure whether an active compound of medicinal plants which is inputted by an user would have an anti-inflammation effects. We developed the visualization program which could show the change of concentration over time.

• Smart Structures and Systems
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• 제2권2호
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• pp.115-126
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• 2006

The Terra-Scope system is an affordable 4-D down-hole seismic monitoring system based on independent, microprocessor-controlled sensor Pods. The Pods are nominally 50 mm in diameter, and about 120 mm long. They are expected to cost approximately $6000 each. An internal 16-bit, extremely low power MCU controls all aspects of instrumentation, eight programmable gain amplifiers, and local signal storage. Each Pod measures 3-D acceleration, tilt, azimuth, temperature, and other parametric variables such as pore water pressure and pH. Each Pod communicates over a standard digital bus (RS-485) through a completely web-based GUI interface, and has a power consumption of less than 400 mW. Three-dimensional acceleration is measured by pure digital force-balance MEMS-based accelerometers. These accelerometers have a dynamic range of more than 115 dB and a frequency response from DC to 1000 Hz with a noise floor of less than $30ng_{rms}/{\surd}Hz$. Accelerations above 0.2 g are measured by a second set of MEMS-based accelerometers, giving a full 160 dB dynamic range. This paper describes the system design and the cooperative shared-time scheduler implemented for this project. Restraints accounted for include multiple data streams, integration of multiple free agents, interaction with the asynchronous world, and hardened time stamping of accelerometer data. The prototype of the device is currently undergoing evaluation. The first array will be installed in the spring of 2006.

• Steel and Composite Structures
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• 제43권2호
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• pp.165-183
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• 2022

Most transportation departments have recognized and developed procedures to address the ever-increasing weights of trucks traveling on bridges in a service today. Transportation agencies also recognize the issues with overheight vehicles' collisions with bridges, but few stakeholders have definitive countermeasures. Bridges are becoming more vulnerable to collisions from overheight vehicles. The exact response under lateral impact force is difficult to predict. In this paper, nonlinear impact analysis shows that the degree of deformation recorded through the modeling of the unprotected vehicle-girder model provides realistic results compared to the observation from the US-61 bridge overheight vehicle impact. The predicted displacements are 0.229 m, 0.161 m, and 0.271 m in the girder bottom flange (lateral), bottom flange (vertical), and web (lateral) deformations, respectively, due to a truck traveling at 112.65 km/h. With such large deformations, the integrity of an impacted bridge becomes jeopardized, which in most cases requires closing the bridge for safety reasons and a need for rehabilitation. We proposed different sacrificial cushion systems to dissipate the energy of an overheight vehicle impact. The goal was to design and tune a suitable energy absorbing system that can protect the bridge and possibly reduce stresses in the overheight vehicle, minimizing the consequences of an impact. A material representing a Sorbothane high impact rubber was chosen and modeled in ANSYS. Out of three sacrificial schemes, a sandwich system is the best in protecting both the bridge and the overheight vehicle. The mitigation system reduced the lateral deflection in the bottom flange by 89%. The system decreased the stresses in the bridge girder and the top portion of the vehicle by 82% and 25%, respectively. The results reveal the capability of the proposed sacrificial system as an effective mitigation system.

• Computers and Concrete
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• 제33권5호
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• pp.497-507
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• 2024

In squat reinforced concrete walls, the displacement capacity for lateral deformation is low and the ability to resist the axial load can quickly be lost, generating collapse. This work consists of testing two squat reinforced concrete walls. One of the specimens is built with conventional detailing of reinforced concrete walls, while the second specimen is built applying an alternative design, including stirrups along the diagonal of the wall to improve its ductility. This solution differs from the detailing of beams or coupling elements that suggest building elements equivalent to columns located diagonally in the element. The dimensions of both specimens correspond to a wall with a low aspect ratio (1:1), where the height and length of the specimen are 1.4 m, with a thickness of 120 mm. The alternative wall included stirrups placed diagonally covering approximately 25% of the diagonal strut of the wall with alternative detailing. The walls were tested under a constant axial load of 0.1f'cAg and a cyclic lateral displacement was applied in the upper part of the wall. The results indicate that the lateral strength is almost identical between both specimens. On the other hand, the lateral displacement capacity increased by 25% with the alternative detailing, but it was also able to maintain the 3 complete hysteretic cycles up to a drift of 2.5%, reaching longitudinal reinforcement fracture, while the base specimen only reached the first cycle of 2% with rapid degradation due to failure of the diagonal compression strut. The alternative design also allows 46% more energy dissipation than the conventional design. A model was used to capture the global response, correctly representing the observed behavior. A parametric study with the model, varying the reinforcement amount and aspect ratio, was performed, indicating that the effectiveness of the alternative detailing can double de drift capacity for the case with a low aspect ratio (1.1) and a large longitudinal steel amount (1% in the web, 5% in the boundary), which decreases with lower amounts of longitudinal reinforcement and with the increment of aspect ratio, indicating that the alternative detailing approach is reasonable for walls with an aspect ratio up to 2, especially if the amount of longitudinal reinforcement is high.

• 마케팅과학연구
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• 제20권2호
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• pp.188-198
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• 2010

此研究旨在考察负口碑(即NWOM)对在线行销的影响, 着重分析服务失败的描述以及通信服务商的意向是如何影响消费者对企业竞争力的评估, 对企业的态度, 以及积极的口碑行销和行为意向. 对通信说服力的研究着重于 "谁说了什么; 对谁;通过何渠道;有何影响(Chiu 2007)". 在此我们研究了电子网络发布, 尤其是 "什么" 的两个方面: 通信服务失败的等级以及个人发布的知觉意向. 电子负口碑看似正在毁掉产品或企业的声誉, 这也就不难理解为什么人们总对它带有偏见, 认为其不可靠. 根据归因理论, 人们总会寻求事件的原因, 尤其是那些消极的意外的事件(Weiner 2006). Hennig-Thurau和Walsh (2003)提出 "既然读者的知识和对在线信息的作者信任度都很有限, 可以把电子口碑当做是表达-行为关系的有效调节. 此据此我们提出以下假设: 假设1. 在衡量(a)企业竞争力, (b)人们对企业的态度, (c)积极的口碑, 以及(d)行为意向时, 面临高等级服务失败电子负口碑的对象得分低于面临低等级服务失败电子负口碑的对象. 假设2. 在衡量(a)企业竞争力, (b)人们对企业的态度, (c)积极的口碑, 以及(d)行为意向时, 面临警告意向电子负口碑的对象得分低于面临报复意向电子负口碑的对象假设3. 在电子负口碑中, 服务失败的等级和知觉意向互相影响, 因此在衡量(a)企业竞争力, (b)人们对企业的态度, (c)积极的口碑, 以及(d)行为意向时, 警告意向的电子负口碑的平均反应值大于报复意向的电子负口碑. 主要研究包括一个2 (服务失败的严重性) x 2(警告意向VS报复意向的负口碑)的析因实验. 将通过模拟的在线网络发布信息刺激在线对象. 这一方案描述的服务失败是在传统的零售机构不接受礼物卡, 通过一家在线的研究公司从全国抽样. 共有113个对象参与此研究, 共分析了104份调查问卷. 研究对象认为该方案很现实, 92.3%对此反应强烈. 方案的运作相当令人满意, 所有的措施都经预先的测试验证, 各个项目也经分析证实可靠并有效. 多变量方差分析结果显示多变量间无明显的互相影响, 因此我们只研究主要影响-后倾向和服务失败的严重性. 后倾向主要影响对企业的态度, 积极的口碑和行为意向. 服务失败的严重性主要影响4个因变量: 企业的竞争力, 对企业的态度, 积极的口碑和行为意向. 需特别指出的是, 当电子负口碑描述为严重的服务失败时, 企业的竞争力低于电子负口碑描述为较轻的服务失败时. 当电子负口碑描述为严重的服务失败时, 对企业的态度差于电子负口碑描述为较轻的服务失败时. 当电子负口碑描述为严重的服务失败时, 企业的口碑差于电子负口碑描述为较轻的服务失败时. 当电子负口碑描述为严重的服务失败时, 行为意向低于电子负口碑描述为较轻的服务失败时. 因此, 假设1中的abcd都得到了支持. 另外, 衡量对企业的态度时, 警告意向的电子负口碑得分低于报复意向的电子负口碑. 衡量企业的口碑时, 警告意向的电子负口碑得分低于报复意向的电子负口碑. 衡量行为意向时, 警告意向的电子负口碑得分低于报复意向的电子负口碑. 因此与假设2中的a项不符, 尽管结果指向的是假设方向. 除此之外, 在假设的三个变量中, 后倾向对服务失败的严重性无明显的多变量或单变量影响. 因此, 假设3被推翻. 此研究有研究和管理的双重蕴涵, 如之前的研究一样, 此研究结果证实了服务失败的严重性影响消费者知觉, 态度, 积极的口碑以及行为意向(Weun et al. 2004). 关于进一步的相关性, 在线内容证实了该反应, 这意味着企业需要努力进行服务补救. 至于电子负口碑的知觉意向, 如之前的研究一样, 此研究结果意味着读者对原始资料的意向影响其对知觉, 态度, 积极口碑和行为意向的作用大小. 对管理者的蕴涵在于, 当消费者发现在线交流可靠且有影响力时, 不是所有的交流都同等重要. 电子口碑的好处在于它可以监测潜在的问题并提供纠正的可能性, 即使有潜在的危害.

• 인터넷정보학회논문지
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• 제12권4호
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• pp.181-194
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• 2011

서버 푸시는 브라우저의 긴 폴링 요청을 이용하여 실시간으로 서버에서 브라우저로 컨텐츠를 전송하는 기술로, HTTP 환경에서 서버와 브라우저간의 실시간 양방향 통신을 가능하게 한다. 최근 풀 브라우징이 가능한 모바일 기기의 급속한 보급으로 인해 서버 푸시는 다양한 응용에 적용되고 있다. 하지만 서비스를 제공하는 서버는 다양한 사용자 환경에서 여러 서버에 분산된 컨텐츠를 동시에 많은 사용자에게 제공해야 하기 때문에 이전 보다 훨씬 많은 동시 사용자를 적절히 식별하여 빠르게 컨텐츠를 제공해야 하는 부담을 안게 되었다. 분산 서버 환경에서 지금까지의 요청 대 응답방식의 서버간 메시지 교환은 이런 요건을 충족하기에 동시 사용자 요청 처리, 사용자의 식별 및 컨텐츠의 전달에 어려움이 있다. 본 연구에서는 분산 서버 환경에서 서버 푸시를 제공하기 위한 서버간 메시지 교환 아키텍처를 제안한다. 제안한 아키텍처는 이벤트 주도 아키텍처를 기반으로 서버간에 푸시 방식으로 메시지를 교환한다는 특징을 가진다. 또한 대량 사용자 접속환경에서 유연한 이벤트 주체의 식별과 이벤트 처리가 가능하다. 본 연구에서는 제안한 아키텍처를 설계 및 구현하였고, 성능 테스트를 통해 기존 방식과 성능을 비교하였으며, 사례 구현을 통해 기능성을 확인하였다. 성능 테스트 결과 동일한 수의 동시 사용자를 처리하는데 제안한 아키텍처는 기존 요청 대 응답방식의 메시지 교환에 비해 서버 Thread 사용량은 감소하였고, 동시 처리량은 증가하였으며, 사용자의 응답시간은 감소하였다.