• Journal of Navigation and Port Research
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• v.44 no.4
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• pp.347-353
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• 2020

Aids to Navigation (AtoN) contribute to preventing marine accidents and protecting marine environment by providing various information such as location information etc. to ships. Recognizing the importance of the AtoN, a 24 won of the AtoN service fee is charged for ships entering and leaving international trade ports. However, while the 24 won of the AtoN service fee has been maintained since its establishment in 1999, the demand for new roles of the AtoN service for autonomous shipping and smart port operations, etc. has gradually increasing with the change of shipping and port 4.0. Thus the purpose of this study was to estimate the appropriate level of the AtoN service fee in accordance with such changes in the shipping and port industries. To accomplish this, a method of recovering the total cost was introduced to the PROOF (Pyeongtaek Regional Office of Ocean and Fisheries). It is estimated that there are four cases in which estimation of the AtoN service fee is estimated in two cases year by year and conversion year, the AtoNs of PROOF are classified into the all and part of a ship using the trade port. As a result of the estimation, the AtoN service fee of PROOF is estimated at 53.78-71.62 won (as of 2019), and 29.78-47.62 won is higher than the today at 24 won. The results of this study can be used as useful basic data for the operation of budgets and policy management considering the role of the AtoN.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.86-95
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• 2006

Brillouin backscatter is a type of reflection that occurs when light is shone into an optical fibre. Brillouin reflections are very sensitive to changes in the fibre arising from external effects, such as temperature, strain and pressure. We report here several case studies on the measurement of strain using Brillouin reflections. A mechanical bending test of an I beam, deployed with both fiber optic sensors and conventional strain gauge rosettes, was performed with the aim of evaluating: (1) the capability and technical limit of the DTSS technology for strain profile sensing; (2) the reliability of strain measurement using fiber optic sensor. The average values of strains obtained from both DTSS and strain gauges (corresponding to the deflection of I beam) showed a linear relationship and an excellent one-to-one match. A practical application of DTSS technology as an early warning system for land sliding or subsidence was examined through a field test at a hillside. Extremely strong, lightweight, rugged, survivable tight-buffered cables, designed for optimal strain transfer to the fibre, were used and clamped on the subsurface at a depth of about 50cm. It was proved that DTSS measurements could detect the exact position and the progress of strain changes induced by land sliding and subsidence. We also carried out the first ever distributed dynamic strain measurement (10Hz) on the Korean Train eXpress(KTX) railway track in Daejeon, Korea. The aim was to analyse the integrity of a section of track that had recently been repaired. The Sensornet DTSS was used to monitor this 85m section of track while a KTX train passed over. In the repaired section the strain increases to levels of 90 microstrain, whereas in the section of regular track the strain is in the region of 30-50 microstrain. The results were excellent since they demonstrate that the DTSS is able to measure small, dynamic changes in strain in rails during normal operating conditions. The current 10km range of the DTSS creates a potential to monitor the integrity of large lengths of track, and especially higher risk sections such as bridges, repaired track and areas at risk of subsidence.

• Journal of the Korean Geotechnical Society
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• v.27 no.6
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• pp.17-26
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• 2011

Ground anchor method is one of the most popular reinforcing technology in Korea. For the sound monitoring of slope reinforced by permanent anchor for a long period, monitoring the tension force of ground anchor is very important. However, special technology except conventional load cell has not been developed for this purpose. In this paper, a new method is described to replace the conventional strain gauge and V.W. type load cell which has been commonly used as a prestress force monitoring tool for a short-term and long-term. Four 11.5 m long strain detectable tension type anchors were made using FBG sensor embedded tendon since FBG sensor is smaller than strain gauge type load cell and does not have noise from electromagnetic wave. Each two set strain detectable tension type anchors were installed into the different ground conditions, i.e., soft rock and weathered granite soil. Prestress force of ground anchor was monitored during the loading-unloading step from in-situ pullout test using proposed FBG sensor embedded in the tendon and the conventional load cell Test results show that the prestress force monitored from FBG sensor may well be used practically, for it almost matches with that measured from expensive load cell.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.1C
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• pp.102-110
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• 2004

In this paper, we propose a VLSI structure of real-time image compression and reconstruction processor using 2-D discrete wavelet transform and implement into a hardware which use minimal hardware resource using ASIC library. In the implemented hardware, Data path part consists of the DWT kernel for the wavelet transform and inverse transform, quantizer/dequantizer, the huffman encoder/huffman decoder, the adder/buffer for the inverse wavelet transform, and the interface modules for input/output. Control part consists of the programming register, the controller which decodes the instructions and generates the control signals, and the status register for indicating the internal state into the external of circuit. According to the programming condition, the designed circuit has the various selective output formats which are wavelet coefficient, quantization coefficient or index, and Huffman code in image compression mode, and Huffman decoding result, reconstructed quantization coefficient, and reconstructed wavelet coefficient in image reconstructed mode. The programming register has 16 stages and one instruction can be used for a horizontal(or vertical) filtering in a level. Since each register automatically operated in the right order, 4-level discrete wavelet transform can be executed by a programming. We synthesized the designed circuit with synthesis library of Hynix 0.35um CMOS fabrication using the synthesis tool, Synopsys and extracted the gate-level netlist. From the netlist, timing information was extracted using Vela tool. We executed the timing simulation with the extracted netlist and timing information using NC-Verilog tool. Also PNR and layout process was executed using Apollo tool. The Implemented hardware has about 50,000 gate sizes and stably operates in 80MHz clock frequency.

• Journal of the Korean Institute of Educational Facilities
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• v.4 no.1
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• pp.53-64
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• 1997

지난 20여년간의 비약적 경제 성장을 통하여 우리 사회는 모든 물리적 측면에서 양적인 성장과 질적인 발전을 거듭하여 왔다. 이러한 경제 성장기를 거치면서 우리의 삶은 다각도에서 변화를 겪었으며 건축환경에도 많은 변화가 있었다. 정보화, 세계화라는 시대적 흐름은 우리의 생활자체를 급속도로 변화시키고 있으며 업무용 시설을 포함한 모든 건축물이 대형화, 고층화 뿐 아니라 정보화, 현대화되고 있다. 그러나, 교육의 중요성과 이를 뒷받침해 줄 학교 시설의 중요성에도 불구하고 교육환경의 질적 개선은 상대적으로 낙후되어 있는 상황이라고 할 수 있다. 교육개혁위원회의 교육개혁방안이 계속적으로 나오고 있고 서울의 불암초등학교를 필두로 한 시설 현대화 시범학교가 시도별로 마련되고는 있지만 전반적인 교육 환경은 아직 열악한 상태이다. 특히 구도심부에 위치한 초등학교의 경우, 준공된 후 30년 이상 경과된 학교 건물을 사용하고 있는 경우가 적지 않아 안전상의 문제마저 안고 있는 실정이다. 따라서, 건물의 내구 연한이 그 한계에 달해 가고 유지보수비용이 계속적으로 늘어 경제성을 잃어 가고 있는 학교들을 대상으로 한 재건축과제가 신설 학교의 신축 또는 기존학교의 이전 못지 않은 주요 과제로 대두되고 있다. 더욱이 기존 학교의 재건축사업은 수업을 진행시켜가며 철거 및 신축공사가 단계적으로 수행돼야 한다는 어려움을 갖고 있다. 본 연구는 초등학교의 재건축을 위한 기본적인 자료를 정리하고 배치 및 평면 계획을 중심으로 한 계획 대안을 작성, 검토하여 대안별 장단점을 분석한 후 가장 바람직하다고 평가되는 안을 제시하는 것을 연구의 범위로 하였다. 계획안의 작성에 앞서 실시된 문헌조사 및 실측조사를 통하여, 신축되는 홍파초등학교에 필요한 시설의 내용 및 규모가 산정되었는데 특기할 사항은 좁은 대지임에도 불구하고 가능한 체육관 시설을 포함시키고자 하였다는 것이다. 홍파초등학교 부지는 $8,960m^2$ 정도밖에 안되는 좁은 부지로서 운동장도 제대로 확보할 수 없는 상황이었으나 체육관의 높은 활용도 및 장래의 필요성을 고려하여 소규모라도 계획되는 것이 바람직하다고 판단하였다. 열린교육에의 대응, 제반 특별교실의 확충, 식당 및 지하주차장의 확보 등 모든 시설이 현재 및 장차의 사용에 적합하도록 계획하여 현 시설의 1.5배 정도의 연면적을 갖는 신축 계획안을 작성하였다. 서울대학교와 광운대학교에서 분담하여 실시된 계획안의 작성을 통하여 총 4개의 계획안이 도출되었으며 이 대안들을 채광 및 환기, 학년별 zoning, 기능별 zoning, 열린교실의 정도, 지역사회에의 개방성, 재건축 공사의 용이성, 규모, 옥외공간의 활용성, 동선 계획, 조형성 등 10개 항목을 기준으로 평가하였다. 이러한 비교분석을 통하여 결론적으로 제1안을 최적안으로 제시하게 되었으며, 이를 바탕으로 구체적인 최종 설계안이 도출되기를 기대하는 바이다.

• The Journal of the Korean dental association
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• v.49 no.11
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• pp.688-703
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• 2011

Park Myoung Jin (1903-1957) was a respectable leader who disseminated dental medical education to make our path as the leading dental medical education developing a new global history of dental medicine. Dr. Park was born in Seoul on 3 July 1903. He graduated Kyongseong dental medical school and studied at the pharmacology department achieving his M.D. In 1938, as the president representing the Hanseong dentists association equivalent to the Japanese dentists association, Dr. Park participated in various events. After liberation, Dr. Park tried his best to achieve Korean dental medical education as the pursuit of ideal ego with self-centered ego. He reorganized the Kyongseong dental medical school and incorporated it to the Seoul National University dental college. Even during the Korea war, Dr. Park still sincerely carried out his duties as the director of the Seoul National University dental medical college by recruiting university entrants and turned out graduates. In 1954, Dr. Park as the director of the Seoul National University dental medical college, he frontiered an opportunity to adapt the American dental medicine by sending school staffs to study overseas. On 25 June 1954, Dr. Park received 25 years of meritorius service award presented by Seoul National University Dental Medical College. Further, on 6 Aril 1954, Dr. Park became a member of an academic research committee. In April 1946, Dr. Park was elected as the president of the Chosun Dentists Association(Korean Dental Association). On 19 May 1947, Dr. Park was also appointed as the director of the Korea dental medicine association leading the general meetings and academic conferences from 2nd through the 8th sessions. On 30 November 1954, as the president of the Korea dental medicine association, Dr. Park also published the Korea dental association publications. In 1957, Dr. Park donated the school housing for the principle of the Kyongseong dental medical school establishing the basis for the Korea dentists association center. Dr. Park also participated in establishment of the oral hygiene campaigne, dental administration policy, organization of the specialized subject delegation board members and the dental materials association. On 10 December 1955, we can recognize Dr. Park's respective historical consciousness through his declaration 'history is a true record of historical traces of a national'. Dr. Park was a living witness of the Korean dental industry. Especially, he stated that the origin of the Korean dentists association was in the Hanseong dentists association. Dr. Park overcame the pressure and indignity during the Japanese colonization. The joy of liberation did not last long since he also had to experience the fraticidal tragedy of the Korea war. Dr. Park was a professional dental specialist and a leader researching dental medicine. He was a great leader who understood the dental medicine and dedicated for the dentist association and dental medicine association with compassion for the nation and national as a Korean.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.12
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• pp.768-775
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• 2017

Energy harvesting characteristics of trapezoidal piezoelectric cantilever generator, which has a lead zirconate titanate (PZT) laminate film, were compared by longitudinal (3-3) and transverse (3-1) modes. The PZT laminate film, fabricated by a conventional tape casting process, was cofired with Ag electrode at $850^{\circ}C$ for 2 h. A multi-layered Ag electrode by a planar pattern and an interdigitated pattern was applied to the PZT laminate to implement the 3-3 and 3-1 modes, respectively. The energy harvesting performance of the 3-3 mode trapezoidal piezoelectric cantilever generator was better than that of the 3-1 mode. An extremely high output power density of $26.7mW/cm^3$ for the 3-3 mode was obtained at a resonant frequency of 145 Hz under a load resistance of $50{\Omega}$ and acceleration of 1.3 G, which is ~3-times higher than that for the 3-1 mode. Therefore, the 3-3 mode is considered significantly efficient for application to high-performance piezoelectric cantilever generator.

• Journal of the Microelectronics and Packaging Society
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• v.15 no.2
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• pp.37-45
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• 2008

In this study, reliabilities of Cu (60 um)/SnAg (20 um) double-bump flip chip assemblies were investigated for the flip chip interconnections on organic substrates with 100 um pitch. After multiple reflows at $250^{\circ}C\;and\;280^{\circ}C$, bump contact resistances were almost same regardless of number of reflows and reflow temperature. In the high temperature storage test, there was no bump contact resistance change at $125^{\circ}C$ up to 2000 hours. However, bump contact resistances slightly increased at $150^{\circ}C$ due to Kirkendall voids formation. In the electromigration test, Cu/SnAg double-bump flip chip assemblies showed no electromigration until about 600 hours due to reduced local current density. Finally, in the thermal cycling test, thermal cycling failure mainly occurred at Si chip/Cu column interface which was found out the highest stress concentration site in the finite element analysis. As a result, Al pad was displaced out under thermal cycling. This failure mode was caused by normal compressive strain acting Cu column bumps along perpendicular direction of a Si chip.

• Journal of Environmental Science International
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• v.24 no.11
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• pp.1485-1491
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• 2015

There are two treatment processes that are currently applied to ships are the biological treatment process using the activated sludge and the electrochemical treatment. However, neither of them are able to remove both nitrogen and phosphorus due to their limited ability to remove organic matters, which are main causes of the red tide. This study was conducted to identify the characteristics of nitrogen removal factors from manure wastewater by replacing the final settling tank in SBR (Sequencing Batch Reactor) process and applying immersion type hollow fiber membrane. SBR process is known to have an advantage of the least land requirement in special environment such as in ship and the immersion type hollow fiber membrane is more stable in water quality change. As the result, the average in the cases of DO (Dissolved Oxygen) is 2.9(0. 6~3.9) mg/L which was determined to be the denitrifying microorganism activity in anaerobic conditions. The average in the cases of ORP (Oxidation Reduction Potential) is 98.4~237.3 mV which was determined to be the termination of nitrification since the inflection point was formed on the ORP curve due to decrease in the stirring treatment after the aeration, same as in the cases of DO. Little or no variation in the pH was determined to have positive effect on the nitrification. T-N (Total Nitrigen) removal efficiencies of the finally treated water were 71.4%, 72.3% and 66.5% in relatively average figures, thus was not a distinct prominence. In being applied in ships in the future, the operating conditions and structure improvements are deemed necessary since the MEPC (Marine Environment Protection Committee). 227(64) ship sewage nitrogen is less than the standard of 20 Qi/Qe mg/L or the removal rate of 70%.

• Journal of Environmental Science International
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• v.17 no.3
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• pp.287-296
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• 2008

A comprehensive quality survey for heavy metals, organophosphorous and organochlorine residual pesticides, and coplanar PCBs in samples such as water, sediments and soils as well as spiders has been implemented. The samples were undertaken at nine stream sites and their vicinity in August 2006, representing different surrounding environments. The levels of PCBs were expressed as concentrations and WHO-TEFs. Among 12 coplanar PCBs as target compounds in this study, 2,3', 4,4', 5-PentaCB (IUPAC # 118) was the congener with the highest concentration. The total concentrations and TEF values of coplanar PCBs in Siheung stream sediment (heavy industrial complex site located in Ansan city) were 3915.50 pg/g and 0.8366 pg-TEQ/g on a dry weight basis, respectively. Such levels were around 40 times higher compared to sediment from Gapyung stream (green site located in the upper of Myunggi mountain). It is probably due to the direct input of PCBs trom PCBs treatment materials. Organophosphorous (EPN, dementon-s-methyl, diazinon, parathion, and phenthoate) and organochlorine (alpha-BHC, aldrin, 4,4'-DDT, 4,4'-DDE, endosulfan alpha and etc.) pesticides were not detected above 5 ppb of detection limits. The concentrations of Cu and Cd in water and sediment samples from Siheung stream were 44.11 and $0.17ug/m\ell$ and $713.42{\mu}g/g$ and $3.73{\mu}g/g$, respectively, which contained $20\sim40$ times higher concentrations than those from Gapyung stream. In addition to the water and sediment samples, the levels of heavy metals in spider from designated sampling sites were also determined. Heavy metals in spider collected near Siheung stream was appeared to be equivalent and/or a little higher levels with respect to other spiders. Furthermore, the ratio of relative heavy metals (Cu, Cd, and Pb) in spider from each stream site showed a correlation as similar as that of heavy metals in soil samples.