• ETRI Journal
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• 제37권5호
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• pp.1001-1011
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• 2015

Since just-in-time (JIT) has considerable overhead to detect hot spots and compile them at runtime, using sophisticated optimization techniques for embedded devices means that any resulting performance improvements will be limited. In this paper, we introduce a novel static Dalvik bytecode optimization framework, as a complementary compilation of the Dalvik virtual machine, to improve the performance of Android applications. Our system generates optimized Dalvik bytecodes by using Low Level Virtual Machine (LLVM). A major obstacle in using LLVM for optimizing Dalvik bytecodes is determining how to handle the high-level language features of the Dalvik bytecode in LLVM IR and how to optimize LLVM IR conforming to the language information of the Dalvik bytecode. To this end, we annotate the high-level language features of Dalvik bytecode to LLVM IR and successfully optimize Dalvik bytecodes through instruction selection processes. Our experimental results show that our system with JIT improves the performance of Android applications by up to 6.08 times, and surpasses JIT by up to 4.34 times.

• 대한전자공학회논문지SD
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• 제38권12호
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• pp.44-55
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• 2001

MAC(Multiply and ACcumulate) 연산은 DSP와 멀티미디어 데이터 처리의 핵심이 되는 연산이다. 기존의 DSP 혹은 내장형 프로세서의 MAC 연산기들은 주로 3사이클의 latency를 가지며, 한번에 하나씩의 데이터를 처리하므로 성능에 한계를 보인다. 따라서 고성능의 범용 프로세서들은 SIMD(Single Instruction Multiple Data) 연산을 지원하는 MAC 연산기를 실행 유닛으로 내장하는 추세이다. 하지만 이러한 고성능의 연산기는 고성능 범용 프로세서의 특성상 다양한 동작 모드를 지원해야 하고 clock 주파수가 높아야 하므로 파이프라인 기법을 사용하고 이에 따른 컨트롤이 복잡하여 하드웨어 설계가 까다롭고 면적이 큰 문제가 있다. 본 논문에서는 내장형 프로세서에 적합한 64비트 폭을 갖는 SIMD MAC 연산기를 설계하였다. 한 사이클에 누적연산까지 모두 완료하도록 하여 파이프라인 제어의 필요성을 없앴고, 기존의 Booth 곱셈기 구조에 기반하여 약간의 회로 추가로 SIMD 연산이 가능하도록 하였다.

• 한국수정란이식학회지
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• 제25권4호
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• pp.267-272
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• 2010

The present study was to investigate the source of contamination during semen processing for in vitro uses. In the present study, frozen semen was prepared from liquid semen in our laboratory for in vitro fertilization (IVF) experiments due to lack of fresh semen. Antibiotics were added in the frozen semen extender (kanamycin and gentamicin) and in vitro culture (IVC) medium (gentamicin) for further inhibiting growth of microorganisms. Nevertheless, proliferations of microorganisms were observed in IVC culture drop during culturing of IVF embryos using frozen semen. Randomly 3 samples were taken from the liquid semen, frozen semen and egg yolk. Contaminated IVC medium, frozen-thawed semen, liquid semen and egg yolk were cultured in de Man, Rogosa and Sharpe (MRS) agar medium. Whitish colonies were detected in contaminated IVC drop, frozen-thawed semen samples and egg yolk but no colonies were formed in liquid semen samples. Gram-negative and rod-shaped identical bacteria were found in both frozen-thawed semen sample and contaminated IVC drop and egg yolk samples. Enterobacter cloacae were confirmed by API 20E kit according to manufacturer's instruction with identification value (% ID) 94.3% and T index 0.88. Antibiotic susceptibility tests were done according to Clinical and Laboratory Standards Institute (CLSI) by using ampicillin, amikacin, cephalothin, gentamicin, kanamycin, tetracycline, oxytetracycline, sulfamethoxazole trimethoprim, norfloxacin and ciprofloxacin test. Among them Enterobacter cloacae were resistant to ampicillin, amikacin, cephalothin, gentamicin, kanamycin but susceptible to tetracycline, oxytetracycline, sulfamethoxazole trimethoprim, norfloxacin and ciprofloxacin. From these findings it could be suggested that this contamination sources might be from egg yolk.

• 한국컴퓨터교육학회 학술대회
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• 한국컴퓨터교육학회 2018년도 동계학술대회
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• pp.75-78
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• 2018

증강현실은 기존과는 다른 컴퓨팅 환경에 대한 경험을 제공하여 학생의 흥미와 관심을 유발할 뿐만아니라 증강된 현실에서 추가적인 학습자원을 제공할 수 있다는 장점이 있다. 이로인해 최근들어 증강현실을 활용한 다양한 교육환경과 차별화된 교육콘텐츠가 제시되고 있고, 교육적인 효과를 확인하고자 하는 연구들이 수행되고 있다. 본 연구는 기존 증강현실에 기반한 학습콘텐츠에 상호작용성을 향상시킬 수 있는 텐지블 인터페이스를 추가하여 학습자가 자유롭게 탐구할 수 있는 교육환경을 설계하는 것을 목적으로 한다. 설계를 구체적으로 진행하기 위해 2015 교육과정의 과학교과의 내용을 토대로 증강현실에 기반한 텐저블 과학실험실을 제안하였다.

• 한국과학교육학회지
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• 제18권3호
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• pp.347-355
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• 1998

학생의 선개념은 일상적 상황의 경험을 바탕으로 형성된 반면, 과학적 개념은 이상화된 상황을 전제로 하여 형성된 것이므로, 개념변화에 필요한 학생의 인지갈등을 유발하려면 이러한 상황의 불일치를 고려할 펼요가 있다. 또한, 학생들은 자신의 생각과 불일치한 현상을 대면하였을 때, 적당한 보조가설을 도입하여 이를 설명하려 함으로 개념변화가 이루어지지 않을 수 있다. 오히려, 과학적 개념이 일상적 상황에서 잘 맞지 않는다고 학생들이 생각할 수 있으므로, 과학적 개념에 따른 보조 가설을 도입하여 일상적 상황의 현상을 설명할 필요가 있다. 본 연구에서는 이러한 점들을 고려한 개념변화 모형을 구안하고, 이에 따라서 보조 가설의 대비를 통한 인지갈등의 명료화, 이상적 상황의 관찰을 통한 과학적 개념의 개념적 지위 상승, 교량적 실험활동을 통한 학생의 선개념의 지위 하강을 통하여 개념변화가 이루어지게 하는 세 단계로 구성된 학습지도 모형인 '구조화된 대비활동'을 제안하였다.

• 한국학교보건학회지
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• 제2권2호
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• pp.36-61
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• 1989

The purpose of this study was to identify and name clusters of school health program, and to describe some of the characteristics of administratie supports. The literature, materials and public documents were analysed by the chronological events from 1945 to 1989. The result of this study is as follows : 1. A brief summary of the history of school health program was included as an introduction to the analysis of the current programs of school health. Five current school health-program clusters were identified from findings of a study of programs : 1) physical assessment, laboratory examination and health services for the students, 2) health instruction 3) healthful living condition (environmental health), 4) health clinic management, 5) administrative supports. 2. The earliest school- based efforts focused on communicable disease pevention by the ministry of health and social affairs. Annual medical inspection (health assessment) for school children for eyes, ears, nose, and throat were mandated nation-wide in 1951 by physical assessment Act. 3. In 1979, the health instruction of schools to improve the health status of students was improved by health department in the Ministry of Education 4. Experiences in healthful environment were basic components of the school health program. However, without careful planning and supervision these experiences were not contributed to the goal of school health. The formal program of school health environment were initiated in 1979 5. In 1980, the guidelines of school health clinic management were prepared by Ministry of Education such as guidance of essential degrees and facilities in school health clinic. 6. Two patterns of administration of school health programs existed in Korea. In one the school health department operated its own health program and in the other the physical education department operated the health program within the school system. The school health department was established in Ministry of Education from 1979 to 1982. Improved school health programs will be a key element in the comprehensive national child health policy which I will ask the Ministry of Education to develop for the Department.

• 대한치과기공학회지
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• 제30권1호
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• pp.57-63
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• 2008

The purpose of this study was to ascertain the effect of different abutment height and different taper of abutment on retention force of cemented implant-supported prostheses. Test specimens consisted of different abutment height group(3mm, 4mm, 5mm, 6mm, 7mm) and different taper(degrees) abutment group($4^{\circ},\;5^{\circ},\;6^{\circ},\;7^{\circ},\;8^{\circ}$). The surfaces of abutments and crowns were manufactured and finished by automatic lathe(CNC). Luting cement(Tokuso Ionomer) was prepared according to the manufacturer's instruction. And the cylinders were sealed onto the abutments and loaded in compression at 5kg for 10minutes. Excess cement was removed from the abutment-cylinder junction and the specimens were stored at room temparature for 24 hours. Specimens were tested in tension using a universal testing machine. Within the limits of this study, the following conclusions were drawn: 1. The increase in abutment height result in improvement in retention strength(P<0.05). 2. The increase in taper of abutment result in decrease in retention strength(P<0.05). 3. The decrease in abutment height result in decrease in retention strength, besides has a significantly lower retention strength at 3mm abutment height. 4. The increase in taper of abutment result in decrease in retention strength, besides has a significantly lower retention strength at $7^{\circ}$ abutment.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -1
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• pp.289-293
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• 2000

We propose two new algorithms for parallelism-independent scheduling. The machine code generated from the compiler using these algorithms in its scheduling phase is parallelism-independent code, executable in minimum time regardless of the number of the processors in the parallel computer. Our new algorithms have the following phases: finding the minimum number of processors on which the program can be executed in minimal time, scheduling by an heuristic algorithm for this predefined number of processors, and serialization of the parallel schedule according to the earliest start time of the tasks. At run time tasks are taken from the serialized schedule and assigned to the processor which allows the earliest start time of the task. The order of the tasks decided at compile time is not changed at run time regardless of the number of the available processors which means there is no out-of-order issue and execution. The scheduling is done predominantly at compile time and dynamic scheduling is minimized and diminished to allocation of the tasks to the processors. We evaluate the proposed algorithms by comparing them in terms of schedule length to the CP/MISF algorithm. For performance evaluation we use both randomly generated DAGs (directed acyclic graphs) and DACs representing real applications. From practical point of view, the algorithms we propose can be successfully used for scheduling programs for in-order superscalar processors and shared memory multiprocessor systems. Superscalar processors with any number of functional units can execute the parallelism-independent code in minimum time without necessity for dynamic scheduling and out-of-order issue hardware. This means that the use of our algorithms will lead to reducing the complexity of the hardware of the processors and the run-time overhead related to the dynamic scheduling.

• 대한간호학회지
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• 제4권2호
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• pp.67-77
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• 1974

Introduction This study is concerned with improving the nursing education curriculum. The purpose of the study was to 1. Review the basic principles of curriculum development. 2. Determine opinion about current nursing curriculums from recent nursing school graduates. Methods of the study A questionnaire was distributed to 250 nurses, in f general hospitals in Seoul. The nurses were graduated from nursing schools in 1973, but represented all types of nursing programs. The Questionnaire was designed to illicit responses about nursing school curriculums in 5 areas: 1. Establishment of objectives 2. Selection of learning experience 3. Organization of learning experience 4. Instruction 5. Evaluation Summary of the major findings 1. Establishment of objectives Thirty nine point three percent of the nurses said that the first objective of the general nursing education was stated "to educate a nurse as a human being with humanity:" Ninety point eight percent of the total respondents said that thor knew the objectives of the curriculum of their nursing schools, but more half of them (58.3%) understood the objectives vaguely at the time they attended nursing school. 2. Selection of learning experience Thirty nine point eight percent of the respondents said their curriculum contained "only a few" liberal arts courses. 3. Organization of learning experience forty seven point six percent. of the respondents were reported that the number of course hours was "insufficient" in liberal arts courses. Fifty seven point three percent of the nurses felt there was an overemphasis on any special topic in liberal arts courses. 4. Instruction Methods of instruction were as follows: Liberal arts courses-a. lecture which centered on explanation (61.1%), b. lecture which centered on writing (43.7%) Supporting nursing courses-a. lecture which centered on explanation (34.0%). b. laboratory Practice (37.8%) Clinical nursing courses-a. lecture which centered on writing (33.0%), b. clinical practice (38.4%) The percentage of respondents replying that various equipment for the learning activities were "insufficient"were as follows: Liberal arts courses-51.0% Supporting nursing courses-28.6% Clinical nursing courses-37.9% 5. Evaluation In the liberal arts courses, 30.6% o( the respondents answered that the evaluation of records was in their opinion "poor, " and 28.2% of the respondents reported that the method of evaluation was "unfair and discouraging. " "Development of a systematic theory of nursing" was thought to be essential for curriculum improvement. The respondents felt that the junior year was the hardest because 1. Number of subjects was too great (28.1%) 2. Lack of a systematic theory of nursing (14.5%) 3. Conflict due to the difference between nursing theory and nursing practice (21.4%) Recommendations 1. Since this study was limited to nurses who had graduated in 1973, a larger study involving professors, graduate students, and nurses from a wider area is suggested in order to establish the reliability and validity of the present findings. 2. Nursing research should be carried out more actively in order to develope nursing science. 3. A permanent organization for research into ways to improve the curriculum should be established in each nursing school.

• 대한화학회지
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• 제55권2호
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• pp.290-303
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• 2011

발산적 사고력과 수렴적 사고력 신장 모형을 만들고 난 후에 현행 과학 탐구 교수 전략에 함께 사용한 새로운 수업 전략을 개발하였다. 이 연구에서 창의적 사고력은 협의의 측면으로 발산적 사고력이다. 그리고 과학과에서의 문제 해결력은 탐구 능력이며 수렴적 사고인 비판적 사고력이다. 이러한 창의적 문제해결력 지향 탐구 수업 모형에 의한 수업 전략을 사범 대학 학생들에게 1학기 동안 적용하여 그 적용 효과를 알아보았다. 첫 번째, 이 학생들의 창의적 사고력인 발산적 사고력이 유의미하게 신장되었다. 하위 요소로는 문제를 인식하는 기능, 가설을 설정하는 기능, 자료를 변환하고 해석하는 기능에 있어서 발산적 사고력이 유의미하게 신장되었다. 두 번째, 이 학생들의 문제 해결력인 탐구 능력에서의 비판적 사고력이 유의미하게 신장되었다. 하위 요소로는 가설을 설정하는 기능, 자료를 변환하고 해석하는 기능, 결론을 도출하는 기능에 있어서 유의미하게 비판적 사고력이 신장되고 있음을 알 수 있었다. 세 번째, 이 학생들의 창의적 문제 해결력도 유의미하게 신장되었다. 구체적으로 변인 통제 능력을 제외한 나머지 탐구 능력에서 모두 창의적 문제 해결력이 유의미하게 신장 되었다.