• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.271-272
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• 2021

The maintenance and repair work of sidewalk block pavement is a construction that requires a large amount of budget to be invested every year. It is important to establish an appropriate standards for estimating construction cost to ensure proper budgeting and quality. In this study, the standards for estimating the cost of maintenance and construction work for sidewalk blocks that can be applied to the construction volume classified according to the site conditions, construction type, and equipment use differentiated from new construction was established. As a result, the daily construction volume was presented by reflecting excavator and truck as equipment in the combination of paver and common worker. The re-installation was applied by separating the construction volume of sections with general blocks and induction/raised blocks based on the installation of sidewalk blocks after demolition. Generally if block cutting is necessary, the precision construction conditions using a cutting machine were taken into consideration to secure the construction quality. In addition, it has been revised to apply classified construction volume into A and B-Type depending on the park and site conditions.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.295-296
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• 2021

With the recent diversification and complication of buildings, the functions of building are also developing. As much as the development of buildings, the machine or equipment used for them is also developing. Thus, all sorts of domestic/foreign industrial facilities and fire stations in the whole nation are using the electric shutter that could meet the insulation just like the exterior wall of general buildings, for bringing-in/storage and crime prevention/fire prevention. Currently, various types of electric shutters are used. Such wrong operation and poor management are causing many panel-falling accidents. This study researched the reduction of electric shutter panel-falling risk by reviewing the domestic/foreign laws and standards, and researching the new safety equipment. First, the causes for falling and accident types were drawn by analyzing the cases of electric shutter accidents. After that, a checklist as the measures for reducing the falling of electric shutter in building was suggested by analyzing the items for the inspection of electric shutter.

• Korean Journal of Medicinal Crop Science
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• v.5 no.1
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• pp.67-71
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• 1997

Bupleurum falcatum is one of the oldest medicinal crop spontaneously generated as well as cultivated by man and successfully grown during the summer season in Korea. This study was conducted to examine the effect of planting density in the row spacing and hill spacing system using machine seeder on major agronomic traits, yield and labor saving. In 1993 and 1994, a spilt plot design was used with row spacing as the main plot and hill spacing as subplot. Labor saving efficency of the machine seeder reduced 96% than the hand seeding in sowing time required. Number of seeding stand increased, but stem height and number of nodes did not affect with different density in each row and hill spacing. There were reduced with narrow hill spacing on stem diameter, number of branches, shoot weight and root traits. There was no significant interaction between row and hill spacing for any major traits studied except shoot weight. Yield was more increase at 20cm than at 30cm row spacing. For these studies the optiomum density appears to be between drilling or 5cm hill spacing with 20cm row spacing. A highly significant positive correlation was appeared between number of seedling stand and root yield.

• Korean Journal of Food Science and Technology
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• v.46 no.6
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• pp.723-728
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• 2014

The physicochemical characteristics of coffees extracted using 7 different extraction methods were investigated. The pH values of coffees extracted via different extraction methods ranged from 5.26 to 5.54, and coffee extracted by Ibrik had the highest pH among all samples. The soluble solid content and titratable acidity of coffee extracted using an Espresso machine were significantly higher than those obtained using other extraction methods. Furthermore, the total phenol and caffeine contents of coffee extracted using an Espresso machine were 6.46 and 2.65 mg/mL, respectively. In regard to color, the $L^*$, $a^*$ and $b^*$ values of coffee extracted via different extraction methods were in the ranges of 0.81-38.94, 4.49-37.75, and 0.71-66.42, respectively. In regard to the phenolic compounds, the chlorogenic acid, caffeic acid and ferulic acid contents of coffee extracted using an Espresso machine were higher than those obtained by other extraction methods at 0.15 mg/mL, $0.075{\mu}g/{\mu}L$, and $0.019{\mu}g/{\mu}L$, respectively.

• KNOM Review
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• v.23 no.2
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• pp.18-28
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• 2020

With the development of the virtual community, the benefits that IT technology provides to people in fields such as healthcare, industry, communication, and culture are increasing, and the quality of life is also improving. Accordingly, there are various malicious attacks targeting the developed network environment. Firewalls and intrusion detection systems exist to detect these attacks in advance, but there is a limit to detecting malicious attacks that are evolving day by day. In order to solve this problem, intrusion detection research using machine learning is being actively conducted, but false positives and false negatives are occurring due to imbalance of the learning dataset. In this paper, a Random Oversampling method is used to solve the unbalance problem of the UNSW-NB15 dataset used for network intrusion detection. And through experiments, we compared and analyzed the accuracy, precision, recall, F1-score, training and prediction time, and hardware resource consumption of the models. Based on this study using the Random Oversampling method, we develop a more efficient network intrusion detection model study using other methods and high-performance models that can solve the unbalanced data problem.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.769-771
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• 2005

유비쿼터스 컴퓨팅의 기반 설비인 센서 네트워크는 많은 수의 센서 노드들로 구성되며, 각 센서 노드의 하드웨어는 매우 작은 규모이다. 또한 최소한의 전력 소모를 위하여 센서 노드들은 동적으로 재구성되며, 노드들 간의 통신은 무선 네트워크를 통하여 이루어진다. 센서 네트워크는 구축 목적에 따라 네트워크 토폴로지 및 라우팅 방식이 결정되어야 하고, 이와 더불어 센서 노드의 하드웨어와 소프트웨어도 필요에 따라 다양하게 변경되어야 한다. 따라서 센서 네트워즈가 구현되기 전에 시스템 동작과 성능을 예측할 수 있고 소프트웨어 개발 환경도 제공해주는 시뮬레이터가 사용 가능하다면, 시스템 개발 기간을 크게 단축시킬 수 있을 것이다. 기존의 센서 네트워크 시뮬레이터들은 특별한 응용을 위한 특정 기반의 하드웨어와 운영체제에 국한되어 개발되었기 때문에 다양한 센서 네트워크 환경을 지원하기에는 한계가 있으며, 센서 네트워크 설계상의 주요 요소인 전력 소모량 분석이 포함되지 않았다. 따라서 본 연구에서는 특정한 응용이나 운영체제에 제한을 받지 않으면서 다양하게 센서 네트워크 환경을 설계 및 검증할 수 있고 전력 소모량 추정도 가능한 시뮬레이터를 개발하는 것을 목표로 하였다. 본 연구에서 개발한 시뮬레이터는 기계명령어-레일(machine instruction-level)의 이산-사건 시뮬레이션(discrete-event simulation) 기법을 이용함으로써 실제 센서 노드의 프로그램 실행 및 관련 동작들을 세부적으로 예측하는 데 사용될 수 있도록 하였다. 시뮬레이션의 작업부하(Workload)인 명령어 트레이스(instruction trace)로는 ATmega128L 마이크로컨트롤러용으로 크로스 컴파일된 인텔 헥스-레코드 형식(.hex) 또는 S-레코드 형식(.srec)의 파일을 사용한다.들을 해결하고자 프라이버시보호에 새로운 키 생성 방법을 통한 강력한 프로토콜을 제안 한다.하였으나 사료효율은 증진시켰으며, 후자(사양, 사료)와의 상호작용은 나타나지 않았다. 이상의 결과는 거세비육돈에서 1) androgen과 estrogen은 공히 자발적인 사료섭취와 등지방 침적을 억제하고 IGF-I 분비를 증가시키며, 2) 성선스테로이드호르몬의 이 같은 성장에 미치는 효과의 일부는 IGF-I을 통해 매개될 수도 있을을 시사한다. 약 $70 {\~} 90\%$의 phenoxyethanol이 유상에 존재하였다. 또한, 미생물에 대한 항균력도 phenoxyethanol이 수상에 많이 존재할수록 증가하는 경향을 나타내었다. 따라서, 제형 내 oil tomposition을 변화시킴으로써 phenoxyethanol의 사용량을 줄일 수 있을 뿐만 아니라, 피부 투과를 감소시켜 보다 피부 자극이 적은 저자극 방부시스템 개발이 가능하리라 보여 진다. 첨가하여 제조한 curd yoghurt는 저장성과 관능적인 면에서 우수한 상품적 가치가 인정되는 새로운 기능성 신제품의 개발에 기여할 수 있을 것으로 사료되었다. 여자의 경우 0.8이상이 되어서 심혈관계 질환의 위험 범위에 속하는 수준이었다. 삼두근의 두겹 두께는 남녀 각각 $20.2\pm8.58cm,\;22.2\pm4.40mm$으로 남녀간에 유의한 차이는 없었다. 조사대상자의 식습관 상태는 전체 대상자의 $84.4\%$가 대부분이 하루 세끼 식사를 규칙적으로 하고 있었으며 식사속도는 허겁지겁 빨리 섭취하는 경우가 남자는 $31.0\%$, 여자는 $21.4\%$로 나타났고 이들을 제외한 나머지 사람들은 보통 속도 혹은 충분한 시간을 가지고 식사를 하였

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.7
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• pp.675-684
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• 2020

To prevent safety accidents caused by aging pipe infrastructure and to maintain water quality, construction projects for water and sewage pipes are actively conducted across Korea. This study analyzed the criteria situations, site survey details, and regulation revisions related to the calculation of construction cost standards for pipe laying and joining work. The analysis showed that the major causes for revision are the unclear construction scope, limitations in implementing some pipe materials due to installation facility types, workforce focused on ordinary labor, limitations of manual laying work, and the lack of tool hire cost and machine expense-calculation criteria. Field studies were conducted to categorize the pipes according to their features, in addition to identifying the use of lifting heavy equipment and light equipment. In addition, excavation and testing work conducted in connection to pipe laying, as well as the use of skilled labor, were investigated. The current study clarified the work scope through new common items, provides an organization based on the pipe material, adjusted the workforce ratio to focus more on skilled labor, and developed grounds for calculating machine expenses. These revisions were estimated to save approximately 1.28% of the construction costs in each project according to an analysis of the construction cost impact study. truction costs in each project, according to an analysis of construction cost impact study.

• Journal of Biomedical Engineering Research
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• v.35 no.3
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• pp.50-54
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• 2014

It is being tried to control robot arm using brain signal in the field of brain-machine interface (BMI). This study is focused on applying guidance laws for efficient robot arm control using 3D coordinates obtained from Magnetoencephalography (MEG) signal which represents movement of upper limb. The 3D coordinates obtained from brain signal is inappropriate to be used directly because of the spatial difference between human upper limb and robot arm's end-effector. The spatial difference makes the robot arm to be controlled from a third-person point of view with assist of visual feedback. To resolve this inconvenience, guidance laws which are frequently used for tactical ballistic missile are applied. It could be applied for the users to control robot arm from a first-person point of view which is expected to be more comfortable. The algorithm which enables robot arm to trace MEG signal is provided in this study. The algorithm is simulated and applied to 6-DOF robot arm for verification. The result was satisfactory and demonstrated a possibility in decreasing the training period and increasing the rate of success for certain tasks such as gripping object.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.100-103
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• 2023

Recently, development of maritime autonomoust surface ships and eco-friendly ships, production and evaluation research considering various marine environments is needed in the field of optimal routes as the demand for accurate and detailed real-time marine environment prediction information expands. An algorithm that can calculate the optimal route while reducing the risk of the marine environment and uncertainty in energy consumption in smart ships was developed in 2 stages. In the first stage, a profile was created by combining marine environmental information with ship location and status information within the Automatic Ship Identification System(AIS). In the second stage, a model was developed that could define the marine environment energy map using the configured profile results, A regression equation was generated by applying Random Forest among machine learning techniques to reflect about 600,000 data. The Random Forest coefficient of determination (R²) was 0.89, showing very high reliability. The Dijikstra shortest path algorithm was applied to the marine environment prediction at June 1 to 3, 2021, and to calculate the optimal safety route and express it on the map. The route calculated by the random forest regression model was streamlined, and the route was derived considering the state of the marine environment prediction information. The concept of route calculation based on real-time marine environment prediction information in this study is expected to be able to calculate a realistic and safe route that reflects the movement tendency of ships, and to be expanded to a range of economic, safety, and eco-friendliness evaluation models in the future.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.5
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• pp.2550-2558
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• 2013

Poly(o-hydroxyamides)(PHAs) copolymers having oligo(oxy ethylene) pendant in the main chain were synthesized by solution polycondensation reaction at low temperature. Copolymer precursors were studied by fourier transform infrared(FT-IR), differential scanning calorimeter(DSC), thermogravimetric analyzer(TGA), universal testing machine(UTM) and limited oxygen index(LOI). The inherent viscosities of the PHAs measured at $35^{\circ}C$ in DMAc or DMAc/LiCl solution were in the range of 0.74~1.42 dL/g. Solubility of the precursors with higher oligo(oxy ethylene) unit was increased, but the PBOs were nearly insoluble in a variety of solvents. The degradation temperature of the copolymer precursors was recorded in the ranges of $408{\sim}664^{\circ}C$ in nitrogen and char yields showed 13~59% values at $900^{\circ}C$. The mechanical properties and flame retardancy of copolymer precursors decreased with higher oligo(oxy ethylene) unit.