• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.10
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• pp.31-39
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• 2004

This paper illustrates the noise characteristics under chip's core operations according to types of packages and modules for DDR DRAM For analyzing this, the impedance profiles and power noises are analyzed with DRAM chips having commercial TSOP package and commercial FBGA package on TSOP-based DIMM and FBGA-based DIMH In controversy with common concepts, we find that the noise-isolation characteristics of FBGA package are more weak and sensitive on transferred noises than those of the TSOP package. In addition, the simulated results show that the decoupling capacitor locations of modules are more important to control the self and transfer noise characteristics than the lead inductance of the packages. Therefore, satisfying the target spec of the noise suppression and isolation can be achieved through the design of power distribution systems only with considering not only the package types but also the whole module system.

• Journal of Sensor Science and Technology
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• v.8 no.3
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• pp.232-238
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• 1999

Single mode fiber optic interferometers using the Fabry-Perot configuration were embedded in a reinforced concrete structure. These interferometers investigated the character of phase shift and strain for internal loads. The 10 mm length of FFPI in the continuous length of single mode fiber (SMF) were produced with two pieces of SMF coated were $TiO_2$ dielectric film utilizing the fusion splicing technique. The fabricated fiber optic Fabry-Perot interferometer(FFPI) and the 6 mm length of steel bar were buried with specimen ($100{\times}100{\times}50\;mm^3$) which was made of concrete structure. The resin protects FFPI and fiber leads from squeezed concrete. Sensors at different point in the structure were multiplexed by TDM (Time Division Multiplexing) method and the deformation to the external loads at each point could be monitored simultaneously. The output signals were proportional to the external loads applied to the structure and the sensitivity of the sensors were $1.03^{\circ}/kg$ and $0.76^{\circ}/kg$ respectively.

• Korean Chemical Engineering Research
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• v.57 no.2
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• pp.172-176
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• 2019

A benthic microbial fuel cells(BMFC) is fuel cell using electricity produced by decomposing organic matter in a sea or a lake. In this study, we used a gas diffusion layer (GDL) of a polymer electrolyte fuel cell (PEMFC) as a BMFC electrode to find out the operation conditions with high performance. The performance of BMFC was increased as resistance of external resistor increased. It was possible to maintain the performance by avoiding the increase of the contact resistance with the electrode due to corrosion of the lead wire in seawater. The bubble generator was able to increase the maximum power density by more than 2 times and the optimum operating temperature was $40^{\circ}C$.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.9
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• pp.19-27
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• 2002

Characteristics of interconnect lines considering underlayer geometries of a silicon substrate and crossing metal lines are experimentally analyzed through elaborately devised patterns. In this work, test patterns for transmission lines having several kinds of underlayer geometries were devised, and the signal characteristics and responses are measured by S-parameter and time domain reflection meter (TDR). The patterns were designed and fabricated with a deep-submicron CMOS DRAM technology having 1 Tungsten and 2 Aluminum metals. From the analysis of measured results on the patterns, it is founded that the effects of underlayter line structures on line parameters (especially line capacitance and resistance) and signal distortions occurred from them cannot be negligible. The results provide useful and insightful understanding in the skew balance of package leads and global signal lines such as high-speed clock and data lines.

• Information and Communications Magazine
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• v.27 no.11
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• pp.12-19
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• 2010

항만 내에서 선박 체류 시간을 단축시켜 선박의 운항 회전율 극대화 및 컨테이너 처리 현황 정보를 실시간으로 제공하는 동의 선사에 대한 서비스 제공은 항만 간의 경쟁에서 우위를 정하기 위해 매우 중요해지고 있다. 이러한 변화에 대응한 u-Port(또는 smart-Port)는 항만을 통하는 모든 수출입 물류에 대해 u-IT 기술을 기반으로 실시간 경로 추적 등이 가능한 항이다. RFID, RTLS 및 USN 기술을 통한 u-Port 구축 노력과 최근에는 스마트폰, GPS, WiFi, Wibro, 3G, 유무선 통합 등의 기술을 활용한 smart-Port 구축에 대해 논의되고 있다. 이들 첨단항만들은 물류 프로세스의 리드타임단축, 실시간 컨테이너 추적, 무인자동화 등을 가능하게 하여 항만의 시간적 경제적 효율성을 대폭 향상시킬 것이다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.2
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• pp.655-666
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• 2014

Recently, as the appearance and exterior design of the construction structure are highlighted, the irregularly shaped structures are increasing in a construction facility. Many softwares provide a quantity take-off function of 3D object under BIM environment, however, they are focused on the limited function based on the solid modeling method. Because the vast geometric information of the curved surface is difficult to extract in the 3D objects that consist of major changes in vertical section shape as the irregularly shaped structures, it is difficult to express a 3D object as a solid model. On the other hand, the irregularly shaped structures can be expressed in relatively free in the surface model because the surface model consists of points, lines and surfaces. Accordingly, the surface modeling method is suitable for the modeling of large irregularly shaped structures. This study suggests a quantity take-off algorithm for the irregularly shaped structures using the surface modeling approach that is beneficial in the design work of structures. Some case projects are used for verifying the accuracy of the proposed method.

• Journal of the Korean earth science society
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• v.28 no.2
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• pp.214-226
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• 2007

Because precipitation is influenced by various atmospheric variables, it is highly nonlinear. Although precipitation predicted by a dynamic model can be corrected by using a nonlinear Artificial Neural Network, this approach has limits such as choices of the initial weight, local minima and the number of neurons, etc. In the present paper, we correct simulated precipitation by using a multiple linear regression (MLR) method, which is simple and widely used. First of all, Ensemble hindcast is conducted by the PNU/CME Coupled General Circulation Model (CGCM) (Park and Ahn, 2004) for the period from April to August in 1979-2005. MLR is applied to precipitation simulated by PNU/CME CGCM for the months of June (lead 2), July (lead 3), August (lead 4) and seasonal mean JJA (from June to August) of the Northeast Asian region including the Korean Peninsula $(110^{\circ}-145^{\circ}E,\;25-55^{\circ}N)$. We build the MLR model using a linear relationship between observed precipitation and the hindcasted results from the PNU/CME CGCM. The predictor variables selected from CGCM are precipitation, 500 hPa vertical velocity, 200 hPa divergence, surface air temperature and others. After performing a leave-oneout cross validation, the results are compared with the PNU/CME CGCM's. The results including Heidke skill scores demonstrate that the MLR corrected results have better forecasts than the direct CGCM result for rainfall.

• Korean Journal of Food Science and Technology
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• v.13 no.3
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• pp.219-226
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• 1981

To enable off-season peach canning, peaches were halved and processed into solid packs. Following variables were compared in relation to storage stability of solid packs. First as pretreatment-dipping in citric and ascorbic solution after lye peeling; second as pasturization in pouch and hot fill process; third as packaging method-2 ply(PET/PE) and 3 ply(PET/Al/PE) plastic film pouch and metal container; fourth as storage condition $-20^{\circ}C\;and\;-5^{\circ}C$. After 25 weeks storage test, all peaches in different packs were processed into canned peaches just like commercial products, and then quality was organoleptically evaluated from the viewpoint of processing and storage variable of solid packs. The results are follows; 1. Ascorbic acid dipping in 3 ply pouch and citric acid dipping in 2 ply pouch had better quality retention effect than any other pretreatments in respective packing. 2. Pasteurization method gave great effect on the color and texture of the solid pack during storage, but not on the quality of the final canned peach. 3. Can and 3 ply packing were better than 2 ply pouch in storage of solid pack and quality of final canned peach. 4. The $5^{\circ}C$ storage gave better quality than $20^{\circ}C$.

• Journal of Dental Rehabilitation and Applied Science
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• v.40 no.2
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• pp.72-81
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• 2024

Purpose: This study aimed to assess the marginal and internal fit of 3-unit monolithic zirconia fixed partial dentures (FPDs) fabricated via computer-aided design and computer-aided manufacturing (CAD/CAM) from solid working casts and removable die system. Materials and Methods: The tooth preparation protocol for a zirconia crown was executed on the mandibular right first premolar and mandibular right first molar, with the creation of a reference cast featuring an absent mandibular right second premolar. The reference cast was duplicated using polyvinyl siloxane impression, from which 20 working casts were fabricated following typical dental laboratory procedures. For comparative analysis, 10 FPDs were produced from a removable die system (RD group) and the remaining 10 FPDs from the solid working casts (S group). The casts were digitized using a dental desktop scanner to establish virtual casts and design the FPDs using CAD. The definitive 3-unit monolithic zirconia FPDs were fabricated via a CAM milling process. The seated FPDs on the reference cast underwent digital evaluation for marginal and internal fit. The Mann-Whitney U test was applied for statistical comparison between the two groups (α = 0.05). Results: The RD group showed significantly higher discrepancies in fit for both premolars and molars compared to the S group (P < 0.05), particularly in terms of marginal and occlusal gaps. Color mapping also highlighted more significant deviations in the RD group, especially in the marginal and occlusal regions. Conclusion: The study found that the discrepancies in marginal and occlusal fits of 3-unit monolithic zirconia FPDs were primarily associated with those fabricated using the removable die system. This indicates the significant impact of the fabrication method on the accuracy of FPDs.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.6
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• pp.573-578
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• 2004

EED consists of bridgewire, explosive charge, lead pins and metal case. If a firing signal is injected to EED， the explosive charge in EED is initiated by heating of bridgewire. Electromagnetic waves radiated from high power transmitters or radars can also cause unexpected firing of EED. Therefore, EMC design and test requirements for EED in military specifications are established and applied. This report describes the characteristics of RF sensitivity fur a firing fuse which is used fur EMC test instead of a real EED installed in aircraft. RF firing level of the fuse was predicted using transmission line(TL) theory. n sensitivity and RF sensitivity specified in military specifications were measured.