• Journal of the Korean Geosynthetics Society
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• v.16 no.4
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• pp.151-161
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• 2017

A TSL (Thin Spray-on Liner) has a higher initial strength and faster construction time than conventional cementitious shotcrete. Because of its high adhesion and tensile strength, the TSL reinforced concrete show a characteristic like composite materials. In this study, to consider an application to the conventional design method, ASD (allowable stress design), numerical study was used. In the numerical analysis, material and contact properties were adopt from previous studies. Then a thickness of concrete in the tunnel was evaluated with the TSL reinforced case by the ASD concept. In other words, bending compressive stress, bending tensile stress and shearing force of the concrete were considered to determine a thickness of concrete lining by the given boundary conditions. From the numerical analysis, there was no tendency to show by the ASD because the ASD is based on the elastic theory while the TSL typically contributes to reinforcement after yielding.

• Korean Journal of Medicinal Crop Science
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• v.3 no.1
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• pp.35-39
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• 1995

Characteristics of Schizandra chinensis BAILLON collected were investigated the development of the new varieties and the results obtained are as follows: Flowering time of Schizandra chinensis varieties were varied from May 6 to 15. In petal base colors 70% were light pinked-colored, 23% were dark pinkcolored and 23% were white-colored respectively and number fruit set per node are 2 to 3 and 60% of plants were flower set and length of diameter of female flower longer than those of male flowers. Among 155 plants investigated, 125 plants showed below 40% of fruit setting and average fruit setting were 26%, 83% of plants were below 12mm, white 17% were above 12.1mm in fruit length, 100 dry fruit weight was 13.2g on average showing significant variation among plants. Average values of major characteristics of populations of collected varieties were 82.5 in number of fruit set, 68.3 in number of fruits 68.3mm in length of fruit set, 22.8mm in width of fruit set, 10.7mm in length of granule 103.1g in dry fruit weight per plants and ratio of dry fruit was 26.8% respectively.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.197-201
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• 2008

Conceptual cost estimates for domestic highway projects have generally been conducted using governmental unit-price references. Inaccuracies in governmental unit-price data has repeatedly addressed in the Korean construction industry which often lead to poor decision making and cost management practices. Thus, needs for developing a better way of conceptual cost estimating has been widely recognized. This research is considered as the first step in developing such model using real-world cost data based on actual construction activities. The data analyzed in this paper includes 41 P.S.C (Prestressed Concrete) Box bridges which broke into 4 categories based on construction methods such as I.L.M(Incremental Launching Method), M.S.S(Movable Scaffolding System), F.S.M(Full Staging Method), and F.C.M(Free Cantilever Method). Actual design documents; including actual cost estimating documents, drawings and specifications were carefully reviewed to effectively break down cost structures for PSC girder bridges. Among more than 40 cost categories for each P.S.C girder bridge type, 7 of them were identified which accounted for more than 95% of total construction cost (ILM: 99.47%, MSS: 99.22%, FSM: 98.18%, and FCM: 98.12%). In order to validate the clustering of cost categories, the variation of each cost category has been investigated which resulted in between -1.16 % and 0.59%.

• Journal of Digital Convergence
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• v.16 no.7
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• pp.89-96
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• 2018

In this paper, we proposed a parametric estimation method for estimating H/W cost by using the development data of professional service robot in Korea. In addition, we derived the factors and weights that we can estimate the costs depending on the application environmental conditions of the robot. For the analysis, we developed the equation of professional service robot cost estimation using parametric method. We also derived the adjustment factors and following weights through FGI and Delphi for environmental conditions. We have developed a cost estimation equation that reflects the weight, volume, and manufacturing difficulty, and can derive a relational equation that reflects the environmental factors(dust/water, heat/cold, safety, test, technology innovation). This provides an objective basis for estimating the cost of professional service robots and will lead to ongoing research for estimating the H/W development cost of professional service robots. In the future, we will increase reliability by collecting abundant data, and will strengthen models through finding functional factors.

• Journal of The Korean Ophthalmological Society
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• v.59 no.12
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• pp.1195-1200
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• 2018

Purpose: To report a case of anterior segment ischemia after superior and inferior rectus muscle surgery in a patient with superior rectus muscle enlargement. This is the first report in the Republic of Korea of anterior segment ischemia after two rectus muscles surgery. Case summary: An 80-year-old male was referred to our clinic with a 3 years history of diplopia. The patient had 30 prism diopters right eye hypertropia in the primary position and downgaze limitation. The orbital computed tomography scan revealed enlargement of the right superior rectus muscle. He underwent right superior rectus recession and inferior rectus resection. On postoperative day 2, slit lamp examination revealed diffuse corneal edema, Descemet's membrane folding, an aqueous flare and a dilated pupil. Treatment with 45 mg oral steroid was initiated, and 1% prednisolone acetate and 0.5% Levofloxacin eye drops were administered. At postoperative 1 month, the patient was orthophoric in the primary position, and there was no corneal edema, pupil abnormality or aqueous flare. Conclusions: Base on the present case, the possibility of anterior segment ischemia should be considered after even two muscles surgery, and older patients with vertical muscle surgery should be considered more carefully.

• KIPS Transactions on Software and Data Engineering
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• v.10 no.10
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• pp.421-428
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• 2021

The High Efficiency Image File Format (HEIF) is an MPEG-developed image format that utilizes the video codec H.265 to store still screens in a single image format. The iPhone has been using HEIF since 2017, and Android devices such as the Galaxy S10 have also supported the format since 2019. The format can provide images with good compression rates, but it has a complex internal structure and lacks significant compatibility between devices and software, making it not popular to replace commonly used JPEG (or JPG) files. However, despite the fact that many devices are already using HEIF, digital forensics research regarding it is lacking. This means that we can be exposed to the risk of missing potential evidence due to insufficient understanding of the information contained inside the file during digital forensics investigations. Therefore, in this paper, we analyze the HEIF formatted photo file taken on the iPhone and the motion photo file taken on the Galaxy to find out the information and features contained inside the file. We also investigate whether or not the software we tested support HEIF and present the requirement of forensic tools to analyze HEIF.

• Korean Journal of Heritage: History & Science
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• v.46 no.3
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• pp.194-210
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• 2013

Oiled paper (Yuji, 油紙) is an oil impregnated paper which was one of the daily necessities in Korea. As there has not been any accurate research on this subject, this study examined the literature from the Joseon Dynasty to study its origin, nomenclature, usage and production process. Goryeodogyeong (高麗圖經) and Goryeosa (高麗史) allowed the estimation that the origin of oiled paper was the Goryeo Dynasty, but the records of oil and paper in Samguksagi (三國史記) and Nihon Shoki (日本書紀) indicate the possibility that the production of oiled paper can be traced back to the 7th Century. The nomenclature and the usage of oiled paper in the Joseon Dynasty were examined through the Annals of Joseon Dynast (朝鮮王朝實錄), Ilseongnok (日省錄) and Seungjeongwonilgi (承政院日記), while the Royal Protocols of the Joseon Dynasty (Uigwe, 儀軌) and Takjijunjeol (度支準折) together with other literature were examined for its market value, use and materials. The literature from the Joseon Dynasty indicate that oiled paper was used for various everyday commodities with its waterproof, damp-proof and transparent properties and called in various ways according to its use and production process. This study studied the literature on oiled paper from the Joseon Dynasty, but the studies on the restoration of traditional oiled paper are still needed. Therefore, it would be necessary to study the traditional oiled papers in combination with the study of oiled paper relics, the reproduction of traditional oiled paper samples, and the case study of the papermaking masters who have been producing the traditional oiled papers.

• Journal of IKEEE
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• v.23 no.2
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• pp.743-746
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• 2019

In this paper we proposed a new ocean radiation automatic monitoring system. The proposed system has the following characteristics: First, using NaI + PVT mixed detectors, the response speed is fast and precision analysis is possible. Second, the application of temperature compensation algorithm to scintillator-type sensors does not require additional cooling devices and enables stable operation in the changing ocean environment. Third, since cooling system is not needed, electricity consumption is low, and electricity can be supplied reliably by utilizing solar energy, which can be installed at the observation deck of ocean environment. Fourth, using GPS and wireless communications, accurate location information and real-time data transmission function for measurement areas enables immediate warning response in the event of nuclear accidents such as those involving neighboring countries. The results tested by the authorized testing agency to assess the performance of the proposed system were measured in the range of $5{\mu}Sv/h$ to 15mSv/h, which is the highest level in the world, and the accuracy was determined to be ${\pm}8.1%$, making normal operation below the international standard ${\pm}15%$. The internal environmental grade (waterproof) was achieved, and the rate of variation was measured within 5% at operating temperature of $-20^{\circ}C$ to $50^{\circ}C$ and stability was verified. Since the measured value change rate was measured within 10% after the vibration test, it was confirmed that there will be no change in the measured value due to vibration in the ocean environment caused by waves.

• Journal of the Korean Geosynthetics Society
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• v.18 no.1
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• pp.67-77
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• 2019

The grouting method is utilized to reinforce and waterproof poor grounds, enhance the bearing capacity of structures damaged resulting from settlement due to elevation and vibration or differential settlement, and for cutoff. The purpose of this research is to enhance the compressive strength of grout materials by using aramid fiber and develop a high-strength ground improvement method by using blast furnace slag powder. In this regard, this study has conducted a uniaxial compression test after checking the high charge (higher than 50%) of the ratio of blast furnace slag powder and cement at 100:0, 70:30 and 40:60%, adding the aramid mixture based on 0, 0.5 and 1.0% of the cement and furnace slag powder weight and creating sand gels based on surface oiling rate of 0.7 and 1.2%. For the environmental review evaluation, a heavy metal exudation test and a pH test measurement have been conducted. The experiment results showed that 1% increase of aramid fiber led to 1.3 times greater uniaxial compression intensity. As for the hexavalent chrome, a 30% increase in blast furnace slag powder led to approximately 50% decrease in heavy metal exudation. However, the pH test revealed that a 30% increase in blast furnace slag powder resulted in approximately 0.5 increase in pH. Further research on the pH part is needed in the future.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.248-248
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• 2018

새만금 종합개발계획(정부, 2011)에 따른 내부개발의 완료시점은 2030년이며, 방수제 공사와 준설 등과 같이 만경강 및 동진강 유역 내 흐름을 변화시킬 수 있는 공사를 포함하고 있으므로 현재와 2030년의 하천 및 호의 수리특성은 다를 것이라 예상된다. 2030년까지 준설상황 등을 예측하여 반영하는 것은 사실상 불가능하기 때문에 새만금 종합개발계획에서 제시하고 있는 내부개발의 완료시점을 기준으로 홍수사상을 모의하였다. 새만금 호의 물리적인 변화는 수리특성의 변화로 이어질 수 있으며, 이는 상류지역으로 전파가 될 수 있으므로 호내 뿐만 아니라 만경강과 동진강 전역에 대한 홍수시의 수리특성을 검토하였다. 새만금 호와 연결된 만경강과 동진강의 설계홍수량은 대부분의 구간에서 100년 빈도이기 때문에 본 연구에서는 100년 빈도 홍수사상에 대한 분석을 기초로 홍수위 검토를 수행하였고, RCP8.5 시나리오를 적용한 100년 빈도 홍수량과 500년 빈도 홍수량에 대한 추가적인 연구를 수행하였으며, 이 결과를 토대로 취약지구 분석 및 대책 등을 제시하였다. 수치모의는 Delft3D를 이용하였으며, 새만금 유역의 동진강 지구의 실측치와 비교함으로써 모델의 적용성을 검증하였다. 서해안 조위 특성상 새만금 방조제는 조위 영향이 크므로, 이에 본 연구에서는 외조위의 특성을 고려하기 위해 새만금 유역 주변의 12개 조화상수(tidal harmonic constant)를 이용하여 조위에 대한 모의를 별도로 수행하고, 이 결과를 배수갑문의 경계조건으로 이용하였다. 상류 경계조건은 하천기본계획상에 제시된 하천은 이를 이용하였으며, 그 외의 소하천은 유역면적을 이용한 계산법을 사용하여, 선형적 면적 비유량(Specific Discharge, SD) 방법을 적용하여 본류의 유량에 부가하는 방식으로 수행하였다. 수치해석 결과, 준설 구간의 수위는 전반적으로 저하되었으며, 거리에 따른 수면의 경사를 분석한 결과 기존의 하천구역이 준설 등으로 인하여 호수의 특성으로 변화된 것으로 확인하였다. 본 연구에서 취약지구는 홍수위가 제방고의 약 80% 이상 되는 지역으로 결정하였으며, 이를 토대로 취약지구 분석을 수행한 결과 기존 100년 빈도에서 1지점, RCP 8.5 시나리오가 적용된 100년 빈도에서 88지점, 500년 빈도에서 125지점이 잠재적인 치수 위험이 있는 것으로 파악되었다. 기존의 1차원 연구결과와는 차이가 있는 부분은, 다수의 취약지구가 만곡부 또는 합류부 인근에 위치한 것이다. 향후 이러한 상대적인 치수 취약지점에 대해 정밀하고 국부적인 연구를 수행하여 정확한 홍수위 예측을 수행해야 할 것이다.