• 대한임베디드공학회논문지
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• 제2권3호
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• pp.145-154
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• 2007

Dynamic update of kernel can change kernel functionality and fix bugs in runtime. Dynamic update is important because it leverages availability, reliability and flexibility of kernel. An instruction-granularity update technique has been used for dynamic update. However, it is difficult to apply update technique for a commodity operating system kernel because development and maintenance of update code must be performed with assembly language. To overcome this difficulty, we design the function-granularity dynamic update system which uses high-level language such as C language. The proposed update system makes the development and execution of update convenient by providing the development environment for update code which is same for kernel development. We implement this system for Linux and demonstrate an example of update for do_coredump() function which is reported it has a vulnerable point for security. The update was successfully executed.

• 한국자동차공학회논문집
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• 제1권1호
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• pp.59-65
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• 1993

In a spark ignition engine, in order to make research on flame propagation, attentive concentration should be paid on initial combustion stage about the formation and development of flame. In addition, the initial stage of combustion governs overall combustion period in a spark ignition engine. With the increase of the size of flame kernel, it could reach initial flame stage easily, and the mixture could proceed to the combustion of stabilized state. Therefore, we must study the theoretical calculation of minimum flame kernel radius which effects on the formation and development of kernel. To calculate the minimum flame kernel radius, we must know the thermal conductivity, flame temperature, laminar burning velocity and etc. The thermal conductivity is derived from the molecular kinetic theory, the flame temperature from the chemical reaction equations and the laminar burning velocity from the D.K.Kuehl's formula. In order to estimate the correctness of the theoretically calculated minimum flame kernel radius, the researcheres compared it with the RMaly's experimental values.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.479-482
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• 1999

In this paper, we implement and construct a kernel on handhold systems. The goal of this project is to develop issues related to the development of small devices: embedded kernel, power management, user interface issues, networking, and the development of applications for small devices. We explain basic system configuration, kernel activity, device drivers and developing environment in this paper. We also explain detail scheduler activity.

• 한국자동차공학회논문집
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• 제7권8호
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• pp.24-33
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• 1999

This paper investigate the effects of the variations of engine operation condition in the flame kernel formation and developmnet . A model for calculating the initial kernel development in spark ignition engines is formualted. It considered input of electrical energy, combustion energy release and heat transfer to the spark plyg, cylinder head, and unburned mixture. The model also takes into accounts strain rate of initial kernel and residual gas fraction. The breakdown process and the subsequent electrical power input initially control the kernel growth while intermediate growth is mainly dominated by diffusion or conduction. Then, the flame propagates by the chemical energy and turbulent flame expansion. Flame kernel development also influenced by engine operating conditions, for example, EGR rate, air-fuel ration and intake manifold pressure.

• Food Science and Biotechnology
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• 제15권2호
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• pp.289-297
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• 2006

In this study we examined the changes in weight and dimension, protein and amylose contents, and pasting properties of brown rice flour, as well as the gelatinization properties of starch, from two non-waxy japonica cultivars and one waxy japonica cultivar planted in an experimental field in 2002 under the same fertilizer conditions. The weight of both rough and brown rice increased consistently up to 42 days after flowering (DAF) for the non-waxy rice and to 35 DAF for the waxy rice. The changes in dimension of the brown rice kernel indicated that the length was maximized first, followed by breadth and then thickness. The protein content of the non-waxy rice remained fairly constant, but that of the waxy rice decreased by about 1% after 14 DAF. The amylose content of the non-waxy brown rice flour increased, but that of the waxy brown rice flour decreased during kernel development. As the kernel developed, the peak viscosity of the non-waxy rice flour increased up to 35 DAF, after which it decreased, whereas that of the waxy brown rice flour increased consistently. The gelatinization temperature of starch also increased in the waxy rice during kernel development up to 21 DAF. The gelatinization enthalpy of starch, however, increased in all rice cultivars throughout the kernel development.

• 한국작물학회지
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• 제43권1호
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• pp.15-18
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• 1998

Receptivity of corn silk to pollen decreases with time. For effective pollination, it is important to study the receptivity of corn silks in relation to time elapsed after their emergence. Two commercial corn hybrids, 'Kwanganog' and 'Suwon 19', were tested for their silk growth and effects of delayed pollination on kernel development for 1 to 13 days after emergence of the first silk. Silks elongated rapidly for the first 3 days and then gradually decreased. Silks grew more than 30mm per day for the first 3 days and stopped growing on the 11 or 12th day after emergence of the first silk. Filled ear length decreased slowly for the first 8 days, and then decreased rapidly. Similar trends were observed for number of kernel rows and number of kernels per row or ear. The highest numbers of kernels per row or ear were observed when plants were pollinated 2-4 days after silking. These numbers decreased gradually up to 8 days, and then decreased sharply. This result indicates that 8 day-delayed pollination has no influence on kernel development. There were negative correlations between silk length and ear characteristics except kernel weight. Silk growth rate was positively correlated with filled ear length, row number, and kernel number. It might be assumed that delayed pollination by one week after the first silk emerged would not affect on kernel set.

• 한국분말재료학회지
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• 제16권4호
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• pp.254-261
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• 2009

In this study, we investigated the unit process parameters in spherical $UO_2$ kernel preparation. Nearly perfect spherical $UO_3$ microspheres were obtained from the 0.6M of U-concentration in the broth solution, and the microstructure of the $UO_2$ kernel appeared the good results in the calcining, reducing, and sintering processes. For good sphericity, high density, suitable microstructure, and no-crack final $UO_2$ microspheres, the temperature control range in calcination process was $300{\sim}450^{\circ}C$, and the microstructure, the pore structure, and the density of $UO_2$ kernel could be controlled in this temperature range. Also, the concentration changes of the ageing solution in aging step were not effective factor in the gelation of the liquid droplets, but the temperature change of the ageing solution was very sensitive for the final ADU gel particles.

• 한국CDE학회논문집
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• 제6권4호
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• pp.271-276
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• 2001

A geometric kernel is the library of core mathematical functions that defines and stores 3D shapes in response to users'commands. We developed a light geometric kernel suitable to develop CAD/CAM application systems. The kernel contains geometric objects, such as points, curves and surfaces and a minimal set of functions for each type but does not contain lots of modeling and handling functions that are useful to create and maintain complex shapes from an idea sketch. The kernel was developed on MS-Windows NT using C++ with STL(Standard Template Library) but it is compatible with UNIX environments. This paper describes the structure of the kernel including several components: base, math, point sequence curve, geometry, translators. The base kernel gives portability to applications and the math kernel contains basic arithmetic and their classes, such as vector and matrix. The geometry kernel contains points, parametric curves, and parametric surfaces. A neutral fie format and programming and document styles are also presented in this paper.

• 정보학연구
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• 제4권2호
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• pp.25-36
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• 2001

실시간 커널은 시간적인 요소를 가장 핵심으로 고려하여 설계된다. 따라서 실시간 커널은 작은 용량을 가지며 빠르게 예측할 수 있어야 한다. 또한 실시간 스케줄링에 요구되는 많은 변화들을 통해서 실시간 커널에 융통성을 부여해야 한다. 본 논문에서 제안한 분산 이중 실시간 커널 시스템은 실시간 제약들을 고려한 실시간 커널과 일반적인 커널의 특성을 가지도록 설계한다. 실시간 제약 조건인 인터럽트 지연 시간, 스케줄링의 정확성, 메시지 전달시간을 만족하기 위하여 실시간 커널에는 실시간 태스크 처리와 인터럽트 처리, 타이밍을 처리하도록 하였고 비실시간 커널은 일반적인 태스크를 처리하도록 한다. 또한, 기존의 실시간 커널인 RT-Linux, QNX와 제안한 실시간 커널이 인터럽트 지연, 스케줄링 정확성, 메시지 전달시간 등을 비교 분석함으로써 실시간 제약조건을 만족함을 보인다

• 한국정보과학회논문지:시스템및이론
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• 제35권5호
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• pp.223-230
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• 2008

동적인 커널의 업데이트는 복잡한 운영체제 커널의 빈번한 기능 개선 및 버그 수정을 동작 중인 커널의 중단없이 수행하는 것이다. 동적인 업데이트를 위해서는 주로 명령어 단위의 업데이트 기법이 사용되지만 어셈블리 언어 수준에서 개발 및 유지, 보수가 이루어지기 때문에 실제 커널에 적용하기 어렵다. 이런 문제점을 극복하기 위해 우리는 C 언어 수준에서 함수 단위로 동적인 커널 업데이트를 수행하는 시스템을 설계하고 리눅스에 구현하였다. 이 시스템은 업데이트 개발 환경을 커널의 개발 환경과 일치시킴으로써 업데이트의 개발과 수행을 편리하게 하여 실제 커널에의 활용 가능성을 증대시킨다. 우리는 이렇게 증대된 활용 가능성을 실제로 알아보기 위해 이 업데이트 시스템을 이용하여 EXT3 파일 시스템을 간단하게 업데이트하는 사례를 보였다.