• Annual Conference of KIPS
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• 2021.11a
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• pp.476-479
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• 2021

DBMS 파라미터 튜닝이란 데이터베이스에서 제공하는 다양한 파라미터의 값을 조율하여, 최적의 성능을 도출하는 과정이다. 데이터베이스 종류에 따라 파라미터 개수가 수십 개에서 수백 개로 다양하며, 각 기능이 모두 다르기 때문에 최적의 조합을 찾는 것은 쉽지 않다. 선행 연구에서는 BO 기법을 사용하여 적절한 파라미터 값을 추출했지만, 파라미터 개수에 비례하여 차원이 커지는 문제가 발생한다. 본 논문에서는 통계적으로 파라미터를 분류하여 탐색 공간을 줄인 다음 단계적으로 BO 를 수행하는 PBO 방식을 제안한다. 파라미터 값을 랜덤하게 할당하여 벤치마킹한 결과값을 군집화한 후, 각 군집별로 파라미터와의 연관성을 분석해 높은 상관관계를 가진 파라미터를 매칭시켜 분류한다. 제안하는 방법론을 검증하기 위하여 8 가지 회귀 모델과의 비교 실험을 통해 제안한 방법론의 우수성을 검증하였다.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.7
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• pp.774-781
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• 2014

This paper presents a fingerprint database construction method for WLAN RSSI (Received Signal Strength Indicator)-based indoor positioning. When RSSI is used for indoor positioning, the fingerprint method can achieve more accurate positioning than trilateration and centroid methods. However, a FD (Fingerprint Database) must be constructed before positioning. This step is a very laborious process. To reduce the drawbacks of the fingerprint method, a radio propagation model-based FD construction method is presented. In this method, an FD can be constructed by a simulator. Experimental results show that the constructed FD-based positioning has a 3.17m (CEP) error. In this paper, a spatial correlation method is presented to estimate the NLOS(Non-Line of Sight) error included in the FD constructed by a simulator. As a result, the NLOS error of the FD is reduced and the performance of the error compensated FD-based positioning is improved. The experimental results show that the enhanced FD-based positioning has a 2.58m (CEP) error that is a reasonable performance for indoor LBS (Location Based Service).

• Proceedings of the Korean Society of Disaster Information Conference
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• 2016.11a
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• pp.339-342
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• 2016

본 논문에서는 아동은 성인에 비하여 신체적 정신적으로 미성숙하며, 특히 범죄에 있어서는 스스로 대응할 수 있는 능력이 부족한 존재로서 우리 사회 전체가 함께 협력하여 범죄로부터 최우선으로 보호하여야 할 대상이다. 그리나 최근 아동을 대상으로 하는 강력범죄 및 학교 내외에서 발생하는 범죄들이 지속적으로 증가하면서 해마다 이에 대한 대안 및 정책들이 쏟아져 나오고 있다. 아동들은 주로 학교나 통학로, 주거지를 비롯한 주요 활동범위 내에서 범죄 피해를 당한다. 이러한 범죄의 피해를 예방하기 위해 도입된 '환경설계를 통한 범죄예방 기법 (CPTED)'은 도입 초기에 기대와는 달리 지역사회와의 고립이 초래되고, 일률적인 학교 시설 내에 CPTED가 범죄의 사각지대를 만드는 등의 부작용이 초래되고 있다. 또한 지역사회의 아동대상범죄 예방활동 역시도 지역 내 소통부재 및 예산확보 문제 등으로 지역 내 시설의 차별이 생기기도 하며, 제대로 된 범죄 예방활동이 이루어지지 못하고 있는 실정이다. 이에 본고에서는 CPTED의 가이드라인 제정 및 공간의 차이를 통한 다양한 기법의 적용방법을 모색하여 학교 내 시설에서의 아동대상범죄를 예방하고, 전 세계적 추세의 통한 아동안전친화도시 조성을 위한 조례제정 및 기본원칙을 제언하고자 한다.

• Journal of the Korean Geotechnical Society
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• v.22 no.11
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• pp.101-111
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• 2006

Slope stability analysis is a geotechnical engineering problem characterized by many sources of uncertainty. Some of them are connected to the variability of soil properties involved in the analysis. In this paper, a numerical procedure of probabilistic analysis of slope stability is presented based on Spencer's method of slices. The deterministic analysis is extended to a probabilistic approach that accounts fur the uncertainties and spatial variation of the soil parameters. The procedure is based on the first-order reliability method to compute the Hasofer-Lind reliability index and Monte-Carlo Simulation. A probabilistic stability assessment was performed to obtain the variation of failure probability with the variation of soil parameters in homogeneous and layered slopes as an example. The examples give insight into the application of uncertainty treatment to the slope stability and show the impact of the spatial variability of soil properties on the outcome of a probabilistic assessment.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.1
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• pp.12-25
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• 2009

The aim of this study is to analyze the periodical and spatial characteristics of urban crime and to find out the factors that affect the crime occurrence. For these, crime data of Masan City was examined and crime occurrence pattern is ploted on a map using crime density and criminal hotspot analysis. The spatial relationship of crime occurrence and factors affecting crime were also investigated using ESDA (Exploratory Spatial Data Analysis) and SAR (Spatial Auto-Regression) model. As a result, it was found that crimes had strong tendency of happening during a certain period of time and with spatial contiguity. Spatial contiguity of crimes was made clear through the spatial autocorrelation analysis on 5 major crimes. Especially, robbery revealed the highest spatial autocorrelation. However as a autocorrelation model, Spatial Error Model(SEM) had statistically the highest goodness of fit. Moreover, the model proved that old age population ratio, property tax, wholesale-retail shop number, and retail & wholesale number were statistically significant that affect crime occurrence of 5 most major crimes and theft crime. However population density affected negatively on assault crime. Lastly, the findings of this study are expected to provide meaningful ideas to make our cities safer with U-City strategies and services.

• Korea Science and Art Forum
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• v.20
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• pp.227-241
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• 2015

As time is rapidly changing, the culture to represent an era is getting more subdivided and complex. Due to cultural diversity, the influence, cause, characteristics which could be understood in individual field centered by space in the past cannot be understood now only by the viewpoint of one field, and it has become difficult to predict and correspond to the change of the future. With the development of information and knowledge delivery system, various cultural contents to form a space are being created and lapsed, but there are a lot of parts which cannot be explained or understood by only one point of view. To inspect these situation, this study is aimed to draw the cultural and technical causes that became the influence with Suwon Hwaseong, a traditional space with historical superiority, analyze the key factors that became the main factor to form the space, and consider the importance of the related factors. Suwon Hwaseong is a new town formed by the order of King Jeongjo. Suwon Hwaseong at that time was a space with the will and effort of many people who dreamed a new era, and it has a meaning of varoius time ans space as historical facts and cultural values as well as the progress and development of scientific technology. The unstructured data technique which is applied as the method of analysis in this study can be said to be a new value judgement and viewpoint in interpreting the space. Therefore, this study is a new trial to provide a frame for multilaterally interpreting the various traditional space and culture of Korea from the past to the present.

• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.4
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• pp.1-14
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• 2021

This study examined the techniques of creating gardens overseas using native plants from the Korean peninsula, focusing on the case of 'Das Dritte Land', an art garden created in Berlin, Germany. While Korean garden artists are recognized worldwide and are planning to globalize Korean gardens, the purpose of this study is to share information so that Korean gardeners can expand their activities and rediscover the utilization and value of plants native to the Korean peninsula. The work began as part of a project to mark the 30th anniversary of the collapse of the Berlin Wall. To realize the landscape of Korea with the motif of Inwang Jesaekdo, the geographical shape of the Baekdu-Daegan trail was reproduced with black stone, and the naturalization of Korean peninsula species was utilized in the creation of a garden Berlin. It is a surreal bio-top utopia that blooms with the bio-groups of the Korean peninsula. This study examined the process of plant survey analysis, transportation and stabilization, planting planning, composition and monitoring, and targeting the self-growth of the Korean peninsula, which is a symbol of harmony between the South and the North. The planting of Korea's native plants in overseas gardens symbolizes the uniting of the ecosystems on the Korean peninsula. The process of the Korean peninsula's young plants taking root, flowering, and spreading along Germany's previously divided border metaphorically conveys the desire for the unification of the Korean peninsula. In addition, various art programs in the garden space suggest a foundation for cultural dialogue and communication between the two Koreas. Moreover, creating gardens overseas implies that the cooperation of plant research institutes plays an important role in the transfer of plants and the maintenance of life, while the advancement of Korean gardens overseas plays an essential role in the spread of garden culture in our country.

• Journal of the Korean Geosynthetics Society
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• v.5 no.3
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• pp.1-7
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• 2006

The Green Wall system, developed in Austria early 1960, is one of segmental concrete crib type earth retaining wall. Green wall is constructed as procedures that lay the front stretchers, rear stretchers and headers then making a rigid body through harden filled soil of interior cell. Green wall has pro-environmental advantages that able to grow grass in front space of stretchers and decrease cutting ground. In Europe, Green wall used without other reinforcement method. However, green wall used with other reinforcement method like a soil nailing because of environmental problem. This study was performed to introduce the design case by 'Two-Body Translation mechanism' to be able to consider distribution of earth pressure in the soil nailing when designing the green wall using soil nailing system. Also, this study attempts to evaluate the earth pressure change when advanced soil nailing system is constructed using $FLAC^{2D}$ ver. 3.30 program and 'Two-Body Translation mechanism'.

• Spatial Information Research
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• v.22 no.1
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• pp.27-33
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• 2014

Considering the wide coverage, the transparency from climate condition, Interferometric Synthetic Aperture Radar (InSAR) possesses a great potential for the landcover classification as shown in many precedent researches. In addition to the merits of InSAR products for the landcover classification, the time series analysis of InSAR pairs can provide a highly reliable basis to interpret landcover. We applied such idea with the test site in Mountain Baekdu located on the border between North Korea and China. Since it is recently noted as the potential volcanic activation site, the landcover especially the vegetation distribution information is highly essential to validate the reliability of Differential Interferometric Synthetic Aperture Radar (DInSAR) over Mt. Baekdu. The algorithms combining the auxiliary information from Moderate Resolution Imaging Spectroradiometer (MODIS) to analyze the phase coherence and backscatter coefficient of Observing Satellite (ALOS) Phased Array type L-band Synthetic Aperture Radar (PALSAR) was established. The results using InSAR signatures from two polarization modes of ALOS PALSAR showed high reliability for mining landcover and spatial distribution.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.3
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• pp.42-56
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• 2012

This study was carried out to investigate the construction characteristics and the landscaping design skill for Wiyiam at Ongnyucheon(玉流川) in the rear garden of Changdeok Palace focusing on constructing technique, space composition and transformational process of the site. The results of this study were summarized as follows; First, Wiyiam of Ongnyucheon was constructed as garden ornament which was modified the huge bedrock into the shape of the mountain. The waterfall of Wiyiam was originally made of torrent which water flowed into the bottom, but it was reconstructed to take the effect of Inak(離落: the method to drop water from high place) by carving rock into square shape at the era of King Gojong(高宗). Second, main characteristics of Wiyiam appeared in Donggwoldo was the hill built up with a square pond and ground at the back of Wiyiam and the profound scenery of mountains and stream from the view of Wiyiam. Also, pavilions such as Soyojeong(逍遙亭), Cheongujeong and Taegeukjeong(太極亭) built in Ongnyucheon seemed to be constructed as the spots to appreciate the view and waterfall sound of Wiyiam. Also the spots were not bounded by the function of creating special water systems such as Cheongujeong pond and Taegeukjeong pond and showed the outstanding landscape design skill to make people feel unusual interest from each spot. On the other hand, this study considered that the evening scenery of Wiyiam, beautiful sound of falling water, unusual water system with beautiful plant materials were landscaped for the function of the psychological peace and stability to the appreciators. Lastly, the extreme change of space composition in Ongnyucheon was assumed as a strategy to improve the existing poor drain environment by confirming that the mountain stream and wall of Soyojeong were removed and drainage in both side of Soyojeong was installed in the 21th year of King Gojong's reign(1884).