• Journal of KIISE:Software and Applications
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• v.26 no.12
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• pp.1393-1403
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• 1999

공간 데이타베이스 시스템을 통하여 공유되는 공간 데이타는 무결성이 적절하게 유지되지 않는 한 전체 응용 시스템의 행위를 예측할 수 없게 되므로 데이타의 무결성 확인 및 유지는 필수적이다. 특히 공공 GIS에 저장된 공간 데이타는 토지 이용도 평가, 도시 계획, 자원 관리, 시설물 관리, 안전 관리, 국방 등 국가 전체 및 지역의 중요한 정책 결정을 위한 다양한 응용 시스템들에 의해 이용되므로 적절한 공간 객체의 무결성 확인이 더욱 더 필요하다. 본 논문에서는 능동(active) DBMS의 능동 규칙(active rule) 기법을 이용하여 공간 객체의 무결성 확인을 지원하기 위한 규칙 관리 시스템을 제시한다. 능동 규칙을 이용한 공간 객체의 무결성 확인은 응용 프로그래머를 무결성 확인에 대한 부담으로부터 자유롭게 할 수 있다. 본 시스템은 특정 DBMS에 종속되지 않는 독립적인 외부 시스템으로 존재하며, 능동 규칙 관리기, 규칙 베이스, 그리고 활성규칙 생성기의 3 부분으로 구성된다. 사용자가 공간 데이타베이스 응용 프로그램을 통해 공간 객체를 조작하고자 할 때, 본 시스템은 데이타베이스 트랜잭션을 단위로 조작되는 모든 공간 객체의 무결성 확인을 위해 응용 프로그램에 삽입될 무결성 제약조건 규칙들을 효율적으로 관리하는 역할을 한다.Abstract It is necessary that the integrity of spatial data shared through the spatial database system is validated and appropriately maintained, otherwise the activity of whole application system is unpredictable. Specially, the integrity of spatial data stored in public GIS has to be validated, because those data are used by various applications which make a decision on an important policy of the region and/or whole nation such as evaluation of land use, city planning, resource management, facility management, risk management/safety supervision, national defense. In this paper, we propose rule management system to support validating the integrity of spatial object, using the technique of active rule technique from active DBMS. Validating data integrity using active rules allows database application programmer to be free from a burden on validation of the data integrity. This system is an independent, external system that is not subject to specific DBMS and consists of three parts, which are the active rule manager, the rule base, and the triggered rule generator. When an user tries to manipulate spatial objects through a spatial database application program, this system serves to efficiently manage integrity rules to be inserted into the application program to validate the integrity constraints of all the spatial objects manipulated by database transactions.

• Journal of Embryo Transfer
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• v.22 no.2
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• pp.137-141
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• 2007

Antioxidants were well known to be essential supplements in the complex media and serve as a reservoir of oxygen. In this study, Hanwoo COCs (cumulus oocytes complexes) were matured and developed in L-cysteine-TCM199 and analyzed metaphase chromosome. Maturation rate of Hanwoo COCs were 73.4%, 94.6% in 0.1% PVA, 0.1 mM L-cysteine, respectively and showed significantly different between the treatments (p<0.05). Blastocyst formation were revealed 20.3%, 10.0% in 5% FBS+TCM199, 0.1 mM L-cysteine+1% BSA, respectively. There were no significant difference among treatment groups. Metaphase chromosome were showed 18.3%, 12.0% in 5% FBS-TCM199, 0.1 mM L-cysteine, respectively and analyzable chromosome were 6.1%, 4.0% and had no differences between the treated groups. In the case of in vitro developmental stages, metaphase chromosome were showed 18.3%, 12.0% in $4{\sim}16$ cells stage, 43.1%, 13.0% in morulae stage and 94.8%, 100.0% in blastocyst stage. These results suggested L-cysteine has beneficial role for in virto maturation and development in Hanwoo COCs.

• Journal of the Korean Institute of Gas
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• v.14 no.2
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• pp.7-14
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• 2010

Synthesis gas was produced by the partial oxidation of methane. For the preparation of catalysts, Ni, known to be active in this reaction and cheap, was used as the active component and $CeO_2$, having high oxygen storage capability and high redox ability, was used as the support. The catalysts were prepared by the impregnation and urea methods. The catalyst prepared by the urea method showed about 11 times higher surface area and finer particle size than that prepared by the impregnation method. The catalysts prepared by the urea method showed higher methane conversion and synthesis gas selectivity than that prepared by the impregnation method. In this reaction, carbon deposition is a problem to be solved, so La was added to the catalyst system to reduce the carbon deposition. TGA analysis results showed that there was 2% carbon deposition with La-added catalysts and 16% with La-free catalysts. It was found that the addition of La decreases the amount of carbon deposition and prevents catalyst deactivation.

• Journal of KIISE:Computer Systems and Theory
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• v.35 no.1
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• pp.18-29
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• 2008

NAND Flash memory has been growing popular storage device for the last years because of its low power consumption, fast access speed, shock resistance and light weight properties. However, it has the distinct characteristics such as erase-before-write architecture, asymmetric read/write/erase speed, and the limitation on the number of erasure per block. Due to these limitations, various Flash Translation Layers (FTLs) have been proposed to effectively use NAND flash memory. The systems that adopted the conventional FTL may result in severe performance degradation by the hot data which are frequently requested data for overwrite in the same logical address. In this paper, we propose a novel FTL algorithm called Adaptive Flash Translation Layer (AFTL) which uses sector mapping method for hot data and log-based block mapping method for cold data. Our system removes the redundant write operations and the erase operations by the separating hot data from cold data. Moreover, the read performance is enhanced according to sector translation that tends to use a few read operations. A series of experiments was organized to inspect the performance of the proposed method, and they show very impressive results.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1094-1099
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• 2012

Green manure cultivation affects soil productivity and nutrient conservation in paddy soil at winter season. This study was to evaluate nitrogen behavior released from chinese milk vetch (CMV) as green manure by using stable $^{15}N$ trace during rice cultivation. The CMV used in the experiment was 29.9 of C/N ratio and 14.1 g N $kg^{-1}$ ($^{15}N$ 0.388 atom % excess) and was applied at rates of 10 and $30Mg\;ha^{-1}$ in pot of 1/2000a size. Rice growth and N uptake increased with higher levels of CMV application at harvesting stage. Among total N uptake, 14.6 and 26.8 % of nitrogen was released respectively from the two different rates of CMV application. Stable $^{15}N$ recovery by rice biomass was 60%, 54% to the $^{15}N$ input, respectively, of CMV application, which decreased in order of grain, root, and straw of rice biomass. Total N content in the soil after rice harvest was 1.9 and 2.1 g N $kg^{-1}$, respectively, with increasing N input by the different rates of CMV application and the rate of $^{15}N$ recovery derived from CMV in the soil was 3.8 and 4.8 %, respectively. N input by CMV application induced rice growth and productivity during rice cultivation. However, it might need proper managements to reduce N loss because about 36-41 % of nitrogen was lost from N input by CMV application.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.258-258
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• 2013

최근 건조 제품의 양질화, 고급화 및 편의화가 요구되어 이를 충족시키기 위한 새로운 건조방법이 계속 개발 되어 왔다. 이러한 방법들 중에서 저온과 진공하에서 건조가 이루어지는 진공 동결 건조는 가장 완벽한 건조 방법으로 최근 실용화 되고 있다. 진공동결건조란 건조의 한 종류로 수분을 함유한 시료를 동결시킨 후 진공펌프를 이용하여 수증기압을 3중점 이하로 낮추어 얼음을 직접 증기로 만드는 승화의 원리에 의해서 얻어진다. 분무진공동결건조의 특징은 (1) 물리적구조의 보존성, (2) 화학적인 안정성, (3) 생물학적인 활동의 보존성, (4) 제품의 높은 복원성 및 재생성이다. 따라서 분무진공동결건조 기술은 크게 진공, 분무, 동결, 건조, 멸균 등과 같은 요소기술의 복합기술이라 할 수 있다. 분말을 제조하기 위해서 진공동결건조 후 분쇄하는 방법을 사용하나 본 방법에서는 정밀화학품 제조를 위해서 분무진공동결건조 방식을 사용한다. 이를 통하여 적당한 크기인 5~10 um의 입경 제조가 가능하고, 공기동력학적인 입경이 기존 방식에 비해 작아서 허파까지의 운반효율이 1.5~2배 우수하다. 화학, 의학 분야에서의 분무동결 건조는 주로 민감한 제품, 즉 생물학적 고유성의 손상 없이 물을 제거하는데 사용되어 영구적으로 저장 가능한 상태로 보관할 수 있으며 물의 첨가로 원상태로 복구할 수 있어서 매우 각광을 받고 있다. 의약용 냉동건조 제품은 항생물질, 박테리아, 혈청, 백신, 검사 약물, 단백질을 포함하는 생물공학 제품들, 세포, 섬유, 화학제품 등이 있으며 주로 vial 또는 ampule 상태로 건조가 이루어진다.본 연구에서는 원료를 $-194^{\circ}C$의 액체질소에 분무시켜 동결된 미립자를 형성한 후 진공 및 저온상태에서얼음의 승화(sublimation)에 기반한 1차 건조와 수증기 탈착(desorption)에 기초한 2차 건조 과정으로 구성된 분무진공동결건조기를 개발하였다. 분무동결 과정의 해석을 통해 2유체식 노즐을 통해 분무된 미세 입경의 액적이 액체 질소 표면까지 도달하는 회수률, 분무 노즐의 위치, 운전 조건 및 용기의 설계의 최적화를 수행하였다. 초기 액적속도, 분무노즐의 높이, 흡입구 추가에 따른 액적 유동 및 회수의 특성을 제시하였으며 이를 통한 분사시스템 고도화 가능성을 제시하였다. 구형의 미세 입자가 적층된 제품의 동결건조 공정의 해석은 흡착승화 모델(sorption sublimation model)을 기반으로 다음과 같은 열전달, 물질전달, 상변화 모델을 고려하여 유도되었다. 분무노즐 및 냉동/진공 배기계 시작품을 개발하여, 표면의 고다공도를 갖춘 입경 3~20 m 정도의 시료를 얻을 수 있으며, 동역학적 입경 5 m 충족함을 확인하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.66-73
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• 2020

In the hydrogen compression cycle, which is currently being developed, hydrogen is compressed to a very high pressure using a compressor, and then stored and used in a high-pressure vessel. This shows that an increase in the temperature of hydrogen in the vessel due to a pressure rise during the filling process and the pressure fatigue due to the repeated cycle may cause problems in the reliability of the vessel. In this paper, for the entire processes in a 50 MPa hydrogen compression system, theoretical and numerical methods were conducted to analyze the following: the temperature increase of hydrogen in the vessel and the time required to reach thermal equilibrium with the surroundings, the change in temperature of hydrogen passing through the pressure reducing valve, and the required capacity of the heat exchanger for cooling the vessel. The results will be useful for the design and construction of hydrogen compression systems, such as hydrogen charging stations.

• Journal of KIISE:Information Networking
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• v.27 no.2
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• pp.109-122
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• 2000

As the full-motion videos in MPEG are widely available nowadays, an editor that could easily edit such kind of media data is required to develop various multimedia applications. In order to concatenate and apply a transition effect to two video streams encoded in MPEG, they should be decoded first since there are dependencies in the frames in MPEG-encoded video stream. Since this decode-edit-encode process requires a huge amount of computing/storage resources, a new editing scheme that could apply various transition effects to MPEG video streams directly while keeping the quality of video data is strongly required. This paper proposes a new editing scheme that could apply three transition effects (such as fade-in, fade-out, and dissolve) to MPEG video streams in a compressed domain. In the proposed scheme, an extension of previous method in which the frames are partially decompressed and transition effects are applied is adopted for I- and P-frames. In addition, a new processing scheme for B-frame that could apply the transition effects in DCT domain directly using an approximation of motion compensation based on the motion vector to reference frames. Since this processing scheme could apply the transition effects in a compressed domain directly, the editing process could be speed-up about $3{\sim}4$ times faster than previous decode-edit-encoding method while keeping the quality of video data as good as the source data. The proposed scheme could be used to build a software-only MPEG video editing system that helps to edit MPEG video data even on a low-cost desk-top computer.

• Journal of the Korean Applied Science and Technology
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• v.36 no.4
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• pp.1128-1135
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• 2019

In this study, different types of polyether amines and H₁₂MDI were used to synthesize water dispersed urea resins, which can be applied to coating material on the concrete slabs for bicycle road using the ordinary application equipments. The concentrations of several polyether amines with different molecular weights and the number of amine functionality were varied to set up the optimal condition for water dispersed urea resin preparation with both an excellent tensile strength and an elongation. In addition, the effect of DMPA[2,2-Bis(hydroxymethyl)propanoic acid] concentration on the storage stability of the water dispersed urea resin was also investigated. The formation of urea bonds from isocyanate and polyether amines was confirmed through FT-IR ATR spectroscopy. From the mechanical properties of urea resins, PU-4 and PU-6, which were prepared with both diamines and triamine of different molecular weights and number of functionality, showed the tensile strength of 10.5 N/㎟ and 12.7 N/㎟, respectively and the elongation of 1165 % and 969%, respectively. Among the water dispersed urea resin synthesized with different contents of DMPA, PU-6 showed the highest mechanical properties, a tensile strength of 14.2 N/㎟ and an elongation of 993%. In addition, the water dispersion state of this PU-6 was the most stable even after 8 weeks.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.5
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• pp.700-705
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• 2012

$Prunus$ $mume$ was steamed for easier removal of the pulp. The steamed fruit pulp was vacuum dried and powdered. The steamed $Prunus$ $mume$ powder (SPP) was passed through a 250 ${\mu}m$ sieve, fluidized in a fluid-bed granulator, and then granulated by top-spraying with water (SPPGW) or the extract obtained from steam (SPPGE). Then the physicochemical and sensory properties of SPP, SPPGW, and SPPGE were evaluated. The flowability of powder (angle of repose $^{\circ}$) of SPP, SPPGW and SPPGE was $23.59^{\circ}$, $11.07^{\circ}$, and $13.94^{\circ}$, respectively. The water dispersibility of SPP, SPPGW, and SPPGE was 18.69, 10.04 and 6.00 sec, respectively. Also, the overall acceptance of SPP, SPPGW and SPPGE was 3.00, 3.44 and 6.56, respectively. In conclusion, SPPGE can be used as granular steamed whole fruit pulp with good powder flowability and dispersibility, and therefore consumer acceptance.