유도결합 플라즈마 질량분석기를 이용한 동물사료중의 극미량원소의 분석

박정화,김효진,Park, Jeoung-Hwa,Kim, Hyo-Jin 대한약학회 1992 약학회지 Vol.36 No.3

The trace elements in animal feed were analyzed by Inductively Coupled Plasma Mass Spectrometer (ICP-MS, VG-PlasmaQuad Co.) to find possible sources of heavy metals accumulation in rat organ. The study about spectral interference was performed by analysis of a background spectrum of ICP-MS. Recovery test using standard of Cd and Se (100 ppb) was found to be better than 90%. Twenty elements (Ca, Fe, Mg, Ti, Cr, Ni, Cu, Zn, Ba, Al, Mn, Pb, B, Ce, Bi, U, V, Cd, and W)are determined.

마이크로파에 의한 Zeolitic Imidazolate Framework 물질, ZIF-8의 합성

박정화,박선혜,정성화,Park, Jung-Hwa,Park, Seon-Hye,Jhung, Sung-Hwa 대한화학회 2009 대한화학회지 Vol.53 No.5

One of zeolitic imidazolate framework materials (ZIF), ZIF-8, has been synthesized with microwave irradiation and conventional electric heating at $140{\sim}180^{\circ}C}$. ZIFs are porous crystalline materials and are similar to metal organic framework (MOF) materials because both ZIFs and MOFs are composed of both organic and metallic components. ZIFs are very stable and similar to zeolites because ZIFs have tetrahedral networks. ZIF-8, with a decreased crystal size, can be synthesized rapidly with microwave irradiation. The microwave synthesis of ZIF-8 is completed in 4 h at $140{^{\circ}C}$ and the reaction time is decreased by about 5 times compared with the conventional electric heating. The ZIF-8 obtained by microwave heating has larger surface area and micropore volume compared with the ZIF-8 synthesized with conventional electric heating. It can be confirmed that ZIF-8s show type-I adsorption isotherms, explaining the microporosity of the ZIF-8s. Based on FTIR and TGA results, it can be understood that the ZIF-8s have similar bonding and thermal characteristics irrespective of heating methods such as microwave and conventional heating. Metal organic frameworks (MOF)과 유사하게 금속과 유기물로 이루어진 골격 물질 중 제올라이 트와 유사한 구조를 갖는 zeolitic imidazolate framework (ZIF)를 처음으로 마이크로파(MW)를 이용하여 합성하였다. ZIF 중 잘 알려진 ZIF-8을 전통적인 전기 가열(CE)과 마이크로파 조사로 합성하였으며 ZIF-8은 $140{\sim}180^{\circ}C}$의 범위에서 용이하게 얻을 수 있었다. MW 합성에 의해 ZIF-8을 신속 하게 합성할 수 있었으며 결정 크기는 전통적인 합성에 비해 전반적으로 감소하였다. $140{^{\circ}C}$에서의 합성 결과 전통 적인 합성에 비해 MW에 의해 약 5배의 반응 속도가 증가함을 알 수 있었고 4시간 이내에 합성 반응이 종료됨을 알 수 있었다. MW로 얻어진 ZIF-8은 CE에 의한 ZIF-8에 비해 증가된 표면적과 세공부피를 가 졌다. 얻어진 모든 ZIF-8은 질소 흡착 실험 결과 type-I 흡착 등온선을 보였고 미세 세공을 가짐을 알 수 있었다. FTIR 및 TGA 결과 두 방법으로 얻어진 ZIF-8은 서로 유사한 결합 및 열적 특성을 보였다.

중증언어장애자 의사소통지원시스템에 관한 연구

박정화,박수현,Park, Jung-Hwa,Park, Su-Hyun 한국정보통신학회 2010 한국정보통신학회논문지 Vol.14 No.1

언어 및 신체장애가 있는 사람들은 의사소통을 하는데 많은 시간이 소요되거나 불가능한 경우도 있으므로 컴퓨터를 이용한 보완 대체 의사소통시스템은 장애인들의 의사소통을 도와주는 중요한 도구이다. 그러나 신체장애를 가진 사람들은 키보드, 마우스 등의 입력장치를 원활하게 사용하지 못하므로 단순한 입력만으로 시스템을 사용하여 의사소통을 할 수 있어야 한다. 따라서 본 논문에서는 간단한 입력만으로 의사소통을 할 수 있는 의사소통지원시스템을 설계하고 구현하였다. 장애인들이 많이 사용하는 빈출문장들을 수집하여 9개 생활언어 그룹으로 분류하여 제시하므로, 몇 번의 선택 동작만을 이용하여 자신이 원하는 문장을 찾을 수 있도록 하였다. 원하는 문장이 없는 경우에는 천지인 자판을 제공하므로 문장을 만들 수 있고, 만들어진 문장을 빈출문장 그룹에 포함시켜서 다음번에 사용할 수 있도록 하였다. 또한 각 그룹에 속한 문장들은 사용자의 사용 빈도에 따라 순위를 바꾸어 줌으로써 가능한 입력 횟수를 감소시킬 수 있도록 개발하였다. It takes a lot of time or is even impossible to communicate for people with physical disability and/or speech impairment. Augmentative and Alternative Communication System is an important computerized tool that makes it possible for those people to communicate. Since not only speech impaired people, but also people with other physical disability cannot use conventional computer input devices easily such as keyboard and mouse, so more simple input devices are need for them to communicate. Thus, in this paper, I designed and implemented a communication aid system, with which they can communicate with simple inputs. I collected frequently used sentences by people with disability and categorized them into 9 everyday language groups. With these categories, they can select any sentence with few simple selections. If none of these categories includes the sentences they want, ChunJiIn keyboard is provided so that they can input the sentences, which can be added to the existing language groups for later use. The priority levels of the sentences in each group is constantly readjusted based on usage frequency so that the number of inputs can be reduced.

글로우방전을 이용한 새로운 정밀분석기기의 개발 및 금속시료의 직접분석법에 관한 연구

박정화,김효진,우진춘,박창준,문대원,이광우,Jeoung Hwa Park,Hyo Jin Kim,Jin Chun Woo,Chang Joon Park,Dae Won Moon,Kwang Woo Lee 대한화학회 1992 대한화학회지 Vol.36 No.2

원자흡수분광법을 위한 글로우방전 분광 장치를 sputtering된 시료원자가 기저상태의 원자가 최대이며 여기 상태의 원자가 최소가 되는 지역을 측정하도록 설계 개발하였다. 빠른 속도의 가스 jet는 방전의 육안 및 전기적 변화 뿐만 아니라 시료표면의 변화에서 처럼 시료가 원자화되는 양을 현저히 증가시킨다. 가스 jet는 원자흡수분광법으로 시료를 직접할 수 있는 가능성을 보여주었다. 감도와 재현성에 영향을 끼치는 여러 가지 요인들에 관하여 연구하였다. A new sputtering chamber, as Atomsource, for atomic absorption measurements was designed and built to have maximum ground state atoms in view and minimum emission. The high velocity gas jets not only change the visual and electrical characteristics of the discharge, but also increase the amount of material atomized, as is apparent from the craters that are produced in the sample where the jets strike the surface. The use of gas jets in a sputtering cell makes this a direct sampling method practical for atomic absorption spectrometry. The factors influencing absorption sensitivity and reproducibility have been investigated for the newly developed atomizer.

고준위폐기물처분시스템 공학적 방벽에서의 지하수 포화공정 해석

박정화,이재완,권상기,Park, Jeong-Hwa,Lee, Jae-Owan,Kwon, Sang-Ki 한국방사성폐기물학회 2011 방사성폐기물학회지 Vol.9 No.1

한국형 기준 처분시스템의 공학적 방벽에서의 열-수리-역학 복합 현상을 실증하기 위한 공학적 규모 실증실험 장치인 KENTEX에서 얻은 열, 수리, 역학적 실험 데이터를 이용하여 벤토나이트의 포화공정을 해석하였다. ABAQUS를 사용한 모델계산의 함수율과 실험 결과의 비교에서 불포화 영역에서는 온도상승으로 인해 초기 수분이 감소하는 수분 재분포 공정을 모델에 포함시키지 않아 함수율의 차가 컸다. 포화 영역에서는 실험에서 초기 수분보다 낮은 함수율에서부터 지하수로 포화가 진행되지만 모델과 실험에서 얻은 함수율 값의 차이가 점점 감소해 완전포화에 도달할 때에는 두 함수율 값이 거의 비슷한 결과를 보여주였다. 포화도 약 95%에 이르는 시간은 실험결과와 계산 결과가 서로 비슷한 약 500일 정도로 예측할 수 있었다. 그리고 불포화 영역의 수분 재분포가 벤토나이트의 완전포화에 도달하는 시간에는 큰 영향을 미치지 않는 것으로 분석되었다. 따라서 본 해석기법을 사용하면 지하처분연구시설의 완충재인 벤토나이트의 포화시간을 예측할 수 있을 것으로 판단된다. An engineering scale test, which is called KENTEX, was carried out to understand and to analyze the coupled thermal, hydrological and mechanical phenomena in the engineered barrier system(EBS) of Korean reference disposal system. Using the experimental data obtained from KENTEX, the water saturation processes in bentonite could be analyzed. From the comparison between the model calculation using ABAQUS and the experimental results, the difference of the water content between them in the unsaturating part was large because the drying phenomena due to moisture redistribution by the temperature gradient could not be included in the model. In the saturating part, the difference of the water content between them was decreased gradually and showed to be small in the full saturation. And the time of about 95% saturation could be estimated about 500 days from the model calculation and experimental results. Also it could be known that the moisture redistribution in the unsaturated part could not be affected on the saturation time of bentonite in the repository. Therefore, it is considered that this model could be used to quantitatively predict the water saturation time in bentonite as EBS for the disposal system.

고준위 방사성 폐기물 처분 시스템 실증 실험용 KENTEX 장치에서의 열-수리-역학 연동현상 해석

박정화,이재완,권상기,조원진,Park Jeong-Hwa,Lee Jae-Owan,Kwon Sang-Ki,Cho Won-Jin 한국방사성폐기물학회 2006 방사성폐기물학회지 Vol.4 No.2

A coupled T-H-M(Thermo-Hydro-Mechanical) analysis was carried out for KENTEX (KAERI Engineering-scale T-H-M Experiment for Engineered Barrier System), which is a facility for validating the coupled T-H-M behavior in the engineered barrier system of the Korean reference HLW(high-level waste) disposal system. The changes of temperature, water saturation, and stress were estimated based on the coupled T-H-M analysis, and the influence of the types of mechanical constitutive material laws was investigated by using elastic model, poroelastic model, and poroelastic-plastic model. The analysis was done using ABAQUS, which is a commercial finite element code for general purposes. From the analysis, it was observed that the temperature in the bentonite increased sharply for a couple of days after heating the heater and then slowly increased to a constant value. The temperatures at all locations were nearly at a steady state after about 37.5 days. In the steady state, the temperature was maintained at $90^{\circ}C$ at the interface between the heater and the bentonite and at about $70^{\circ}C$ at the interface between the bentonite and the confining cylinder. The variation of the water saturation with time in bentonite was almost same independent of the material laws used in the coupled T-H-M processes. By comparing the saturation change of T-H-M and that of H-M(Hydro-Mechanical) processes using elastic and poroelastic material mod31 respectively, it was found that the degree of saturation near the heater from T-H-M calculation was higher than that from the coupled H-M calculation mainly because of the thermal flux, which seemed to speed up the saturation. The stresses in three cases with different material laws were increased with time. By comparing the stress change in H-M calculation using poroelasetic and poroelasetic-plastic model, it was possible to conclude that the influence of saturation on the stress change is higher than the influence of temperature. It is, therefore, recommended to use a material law, which can model the elastic-plastic behavior of buffer, since the coupled T-H-M processes in buffer is affected by the variation of void ratio, thermal expansion, as well as swelling pressure.

공잡기 동작에서 Pattern의 발달과 반응시간의 관계

박정화(Jung Hwa Park) 한국발육발달학회 1999 한국발육발달학회지 Vol.7 No.1

The purpose of this study was to analyze the relationship between ball catching patterns and reaction time in university arid elementary school students. One hundred and ninety four university students(57 males and 137 females) and 74 elementary school children(42 boys and 32 girls) participated in the experiment as subjects. Subjects` task was to catch a softball overhead with their non-dominant hind. The catching performance was video-taped and classified into eye, hand, and foot components. Each component of the catching performance consisted of 3 performance categories, and subjects` performance was scored for each category. Times for bar-gripping reaction and whole body reaction were also measured for each subject. Results of the study indicated the following: 1. Ball catching patterns were different between gender, males displaying better developed patterns than females. 2. Ball catching patterns developed with age, although skilled elementary school boys had similar patterns with university students. 3. While the reaction time differed by age and gender, ball catching skill was not influenced by those factors. 4. For the same age groups and the same gender, ball catching. pattern was not related with reaction time. While male university students showed slower reaction time. and better developed ball catching patterns than elementary school boys, there was no difference in those performances between ages in female. For subjects in the same age, group, those with better developed ball catching patterns displayed faster reaction time. Among the components of ball catching patterns, eye movement and hand movement were shown to be related with reaction time.

차량 네트워크를 위한 긴급메시지 브로드캐스트 기법

박정화(Jeong Hwa Park),강문수(Moonsoo Kang) 한국멀티미디어학회 2012 멀티미디어학회논문지 Vol.15 No.3

실시간 임베디드 운영체제 TMO-eCos의 데드라인 기반 CPU 소비전력 관리

박정화(Jeonghwa Park),김정국(Jungguk Kim) 한국정보과학회 2009 정보과학회 컴퓨팅의 실제 논문지 Vol.15 No.4

본 논문은 실시간 임베디드 OS인 TMO-eCos의 데드라인 기반 CPU 저전력 관리 기법을 다루고 있다. 해당 저전력 관리 기법은 경성 실시간 시스템인 TMO 시스템을 위한 태스크 순차화 기법에서 도출된 스케줄링 시나리오를 사용한다. 본 연구팀에서 개발한 스케줄링 사전 분석기는 주기적으로 동작하는 태스크의 주기, 데드라인, WCET를 기반으로 오프라인 분석을 실시한다. 최종적으로 TMO-eCos 커널은 CPU의 전력 소모를 줄이기 위하여 주기적인 태스크의 데드라인을 위반하지 않는 범위에서 CPU의 속도를 조절하여 시스템에서 사용하는 소비전력은 줄이게 된다. 본 논문은 이와 같은 과정과 실제 실험결과를 기술한다. This paper presents the deadline driven CPU-Power management scheme for the Real-Time Embedded OS: named TMO-eCos. It used the scheduling scenarios generated by a task serialization technique for hard real-time TMO system. The serializer does a off-line analysis at design time with period, deadline and WCET of periodic tasks. Finally, TMO-eCos kernel controls the CPU speed to save the power consumption under the condition that periodic tasks do not violate deadlines. As a result, the system shows a reasonable amount of power saving. This paper presents all of these processes and test results.

광학적으로 투명한 초발수 폴리머 필름의 제작

박정화(J. H. Park),이동원(D. W. Lee),최영수(Y. S. Choi),김동수(D. S. Kim) 한국정밀공학회 2014 한국정밀공학회 학술발표대회 논문집 Vol.2014 No.10월