• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.1
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• pp.47-54
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• 2009

This research is about the inherent optical properties(IOPs) of algae which is collected from Nam-Hae for basic research of red tide remote sensing technique development. 21 kinds of red tide organisms were cultivated to investigate IOPs of them in the level of laboratory, and specific absorption coefficient of phytoplankton($a^*$) and backscattering coefficient of phytoplankton(${b_b}^*$) are estimated by using spectrophotometer. Absorption spectrums according to species appeared to range from 0.005 to 0.06 ($m^2{\cdot}mg^{-1}$), and the shapes of spectrums were also different. The range of ${b_b}^*$ appeared to be $10^{-2}{\sim}10^{-4}\;m^2{\cdot}mg^{-1}$, which had about 100 times differences between species, and the shape of spectrum have significant difference between species. These results will input as a remote sensing reflectance model input parameter from ocean color.

• Proceedings of the KSRS Conference
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• v.1
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• pp.224-227
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• 2006

For estimation of three inherent optical properties (IOPs), the absorption coefficients for phytoplankton ($a_{ph}$) and suspended solid particle ($a_{ss}$) and dissolved organic matter ($a_{dom}$), from ocean reflectance, we used inversion of remote sensing reflectance model (Ahn et al., 2001) at this study. The IOP inversion model assumes that (1) the relationship between remote sensing reflectance ($R_{rs}$) and absorption (a) and backscattering ($b_{b}$) is well known, (2) the optical coefficients for pure water ($a_{w}$, $b_{bw}$) are known, (3) the spectral shapes of the specific absorption coefficients for phytoplankton ($a^*_{ph}$) and suspended solid particle ($a^*_{ss}$) and the specific backscattering coefficients for phytoplankton ($b_b^*_{ph}$) and suspended solid particle ($b_b^*_{ss}$) are known. The input data of IOP inversion model is used in-situ ocean optical data at the seawater around the Korea Peninsula for 5 years (2001-2005). We compared the output data of the IOP inversion model and the in-situ observation for seawater around the Korea Peninsula.

• Atmosphere
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• v.18 no.2
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• pp.147-158
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• 2008

Domestic IOP (intensive observing period) has mostly been represented by the KEOP (Korea Enhanced Observing Period), which started the 5-yr second phase in 2006 after the first phase (2001-2005). During the first phase, the KEOP had focused on special observations (e.g., frontal systems, typhoons, etc.) around the Haenam supersite, while extended observations have been attempted from the second phase, e.g., mountain and downstream meteorology in 2006 and heavy rainfall in the mid-central region and marine meteorology in 2007. So far the KEOP has collected some useful data for severe weather systems in Korea, which are very important in understanding the development mechanisms of disastrous weather systems moving into or developing in Korea. In the future, intensive observations should be made for all characteristic weather systems in Korea including the easterly in the central-eastern coastal areas, the orographically-developed systems around mountains, the heavy snowfall in the western coastal areas, the upstream/downstream effect around major mountain ranges, and the heavy rainfall in the mid-central region. Enhancing observations over the seas around the Korean Peninsula is utmost important to improve forecast accuracy on the weather systems moving into Korea through the seas. Observations of sand dust storm in the domestic and the source regions are also essential. Such various IOPs should serve as important components of international field campaign such as THORPEX (THe Observing system Research and Predictability EXperiment) through active international collaborations.

• Proceedings of the KSRS Conference
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• 2009.03a
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• pp.280-285
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• 2009

1998년 8월부터 2005년 6월까지 한반도 주변 해역에서 현장관측한 해수의 고유 광특성(IOPs)과 외형적 광특성(AOPs) 자료들을 이용하여 원격반사도$(R_{rs}(\lambda))$와 성분별 흡광계수의 총 합 $(\alpha(\lambda)=\alpha_w(\lambda)+\alpha_{ph}(\lambda)+\alpha_{ss}(\lambda)+\alpha_{dom}(\lambda))$의 상관관계를 분석하고, $R_{rs}(\lambda)$ 밴드비를 이용하여 흡광계수 산출 알고리즘을 개발하였다. 파장에 따른 $R_{rs}(\lambda)$와 총합 $\alpha(\lambda)$의 상관관계는 반비례적인 관계를 보였고, 파장 443 nm일 때 상관도$(R^2)$는 0.717이다. $\alpha_{ph}(\lambda)$ 산출알고리즘은 엽록소의 흡광과 관련된 파장 490 nm와 부유물의 산란과 관련된 파장 555 nm의 $R_{rs}(\lambda)$ 밴드비의 함수 형태로 구성하였고, 파장 443 nm일 때 RMS 값은 0.223이다. $\alpha_{ss}(\lambda)$과 $\alpha_{dom}(\lambda)$ 산출 알고리즘은 용존유기물의 흡광과 관련된 파장 412 nm와 부유물의 산란과 관련된 파장 555 nm의 $R_{rs}(\lambda)$ 밴드비의 함수 형태로 구성하였고, 파장 412 nm일 때 RMS 값은 각각 0.324와 0.230이다. $\alpha_{ph}(\lambda),\;\alpha_{ss}(\lambda),\;\alpha_{dom}(\lambda)$ 산출 알고리즘들은 대체적으로 현장값보다 높게 추정하였고 스펙트럼들은 잘 재현해냈다. 추후 이에 대한 개선과 알고리즘의 검보정이 요구된다.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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• pp.148-150
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• 2013

최근 TCP/IP에서 세션을 통하여 노드들 간의 통신을 연결하는 방식에서 현재는 하나의 채널을 통해 고속의 I/O가 가능하도록 하는 인피니밴드 같은 기술이 많이 연구되고 있다. 인피니밴드는 프로세싱 노드와 입출력 장치 사이의 통신, 프로세스간 통신에 대한 산업 표준이 되고 있고 프로세싱 노드와 입출력 장치를 연결하기 위해 스위치 기반의 상호 연결은 전통적인 버스 입출력을 대체하는 새로운 입출력 방식이다. 또한 인피니밴드에서는 현재 이슈가 되고 있는 RDMA 방식을 이용해 원격지 서버들간에 직접 메모리 접근 방식을 통해 CPU와 OS의 로드를 최소화하고 있다. 본 논문에서는 인피니밴드 네트워크를 이용하는 저장장치 접근 프로토콜인 iSER(iSCSI Extension RDMA Protocol)와 기존 이더넷망에서 사용되는 iSCSI(Internet SCSI) 프로토콜을 이용하여 서버와 저장장치 간의 IOPS 와 초당 데이터 전송량에 대한 성능을 평가한다. 우리는 성능평가를 위해 Intel에서 제공하는 저장장치 I/O 성능평가 도구인 IO meter를 이용했다.

• Earthquakes and Structures
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• v.19 no.1
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• pp.45-57
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• 2020

This paper presents the experimental application of a new method for seismic vulnerability assessment of buildings recently introduced in literature, the SMAV (Seismic Model Ambient Vibration) methodology with reference to their operational limit state. The importance of this kind of evaluation arises from the civil protection necessity that some buildings, considered strategic for seismic emergency management, should retain their functionality also after a destructive earthquake. They do not suffer such damage as to compromise the operation within a framework of assessment of the overall capacity of the urban system. To this end, for the characterization of their operational vulnerability, a Structural Operational Index (IOPS) has been considered. In particular, the dynamic environmental vibrations of the two considered strategic buildings, the fire station and the town hall building of a small town in the South of Italy, have been monitored by positioning accelerometers in well-defined points. These measurements were processed through modern Operational Modal Analysis techniques (OMA) in order to identify natural frequencies and modal shapes. Once these parameters have been determined, the structural operational efficiency index of the buildings has been determined evaluating the seismic vulnerability of the strategic structures analyzed. his study aimed to develop a model to accurately predict the acceleration of structural systems during an earthquake.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.37 no.6
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• pp.555-562
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• 2019

This paper presents soil deformation measurement in model chamber based on photogrammetry. We created an aluminum framed acrylic model chamber with soil inside and applied photogrammetry to measure soil deformation caused by loading tests. The soil consists of 40% black and 60% regular sand to create image contrast in soil images. In preprocessing, the self camera calibration was carried out for IOPs (Interior Orientation Parameters), followed by the space resection to estimate EOPs (Exterior Orientation Parameters) using control points located along the aluminum frame. Image matching was applied to measure the soil displacement. We tested different matching window sizes and the effect of image smoothing. Experimental results showed that 65x65 pixels of window size produced better soil deformation map and the image smoothing was useful to suppress the matching outliers. In conclusion, photogrammetry was able to efficiently generated soil deformation map.

• Journal of Veterinary Clinics
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• v.34 no.5
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• pp.341-346
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• 2017

This study was performed to evaluate the effects of an intravitreal injection of cidofovir in beagle dogs. Nine beagle dogs (18 eyes) were used and randomly assigned to the following three groups of various dosages: 100, 500 and $1000{\mu}g$. Aqueous paracentesis was followed by an intravitreal injection of cidofovir. Intraocular pressure (IOP) was measured twice a week and electroretinography (ERG) and ophthalmoscopic examination were performed every week during the study. At the end of the study, all eyes were enucleated for histopathologic evaluation after euthanasia. The IOPs in the 500 and $1000{\mu}g$ groups were statistically lower than baseline with no significant IOP changes in the $100{\mu}g$ group. Reduced amplitudes of ERG recordings were identified in the eyes injected with higher dose groups than the $100{\mu}g$ group. Histopathologic examination revealed that there were dose-related toxicities to the ciliary body and the retina. These results suggest that intravitreal cidofovir had dose-dependent IOP lowering effects associated with ciliary body destruction, but had the potential to cause retinal toxicity in beagle dogs.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.8C
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• pp.670-679
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• 2012

The recent dissemination of cloud computing makes the amount of data storage to be increased and the cost of storing the data grow rapidly. Accordingly, data and service requests from users also increases the load on the cloud storage. There have been many works that tries to provide low-cost and high-performance schemes on distributed file systems. However, most of them have some weaknesses on performing parallel and random data accesses as well as data accesses of frequent small workloads. Recently, improving the performance of distributed file system based on caching technology is getting much attention. In this paper, we propose a CHPC(Cloud storage High-Performance Caching) framework, providing parallel caching, distributed caching, and proxy caching in distributed file systems. This study compares the proposed framework with existing cloud systems in regard to the reduction of the server's disk I/O, prevention of the server-side bottleneck, deduplication of the page caches in each client, and improvement of overall IOPS. As a results, we show some optimization possibilities on the cloud storage systems based on some evaluations and comparisons with other conventional methods.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.5
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• pp.805-815
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• 2001

Glaucoma is an eye disease which is caused by abnormal high IOP (Intra Ocular Pressure). High IOP is caused by the aqueous humor which is produced consistently but not drained due to malfunction of the trabecular system which has a role of draining the aqueous humor into the venous system. Currently, there are three methods to treat glaucoma-using medicines, surgical operation, and using implant device. The first and second methods are not long acting, so the use of implants is increasing in these days in order to drain out the aqueous humor compulsory. However, though conventional implants have a capability of pressure regulation, they cannot maintain IOPs desired for different patients, and too much aqueous humor are usually drained, to cause hypotony. To solve these problems, it is needed to develop a new implant which is capable of controling the IOP actively and copes with personal difference of patients. An active glaucoma implant consists of the valve actuator, pressure sensor, controller, and power supply. In this paper, firstly, we make an analysis of the operation of a conventional implant using a bond graph and show defects and limitations of the conventional valve analytically. Secondly, we design and analyze a valve actuator considering actuation principles, resistance elements, control methods, and energy sources focused on power saving problem. Finally, using simulations the possibility of the proposed valve actuator is investigated.