• 한국축산식품학회지
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• 제40권2호
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• pp.183-196
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• 2020

The protective effect of pig skin gelatin water extracts (PSW) and the low molecular weight hydrolysates of PSW generated via enzymatic hydrolysis with Flavourzyme® 1000L (LPSW) against scopolamine-induced impairment of cognitive function in mice was determined. Seventy male ICR mice weighing 20-25 g were randomly assigned to seven groups: Control (CON); scopolamine (SCO, 1 mg/kg B.W., intraperitoneally (i.p.); tetrahydroaminoacridine 10 [THA 10, tacrine; 10 mg/kg B.W. per oral (p.o.) with SCO (i.p.)]; PSW 10 (10 mg/kg B.W. (p.o.) with SCO (i.p.); PSW 40 (40 mg/kg B.W. (p.o.) with SCO (i.p.); LPSW 100 (100 mg/kg B.W. (p.o.) with SCO (i.p.); LPSW 400 (400 mg/kg B.W. (p.o.) with SCO (i.p.). All treatment groups, except CON, received scopolamine on the day of the experiment. The oxygen radical absorbance capacity of LPSW 400 at 1 mg/mL was 154.14 μM Trolox equivalent. Administration of PSW and LPSW for 15 weeks did not significantly affect on physical performance of mice. LPSW 400 significantly increased spontaneous alternation, reaching the level observed for THA and CON. The latency time of animals receiving LPSW 400 was higher than that of mice treated with SCO alone in the passive avoidance test, whereas it was shorter in the water maze test. LPSW 400 increased acetylcholine (ACh) content and decreased ACh esterase activity (p<0.05). LPSW 100 and LPSW 400 reduced monoamine oxidase-B activity. These results indicated that LPSW at 400 mg/kg B.W. is a potentially strong antioxidant and contains novel components for the functional food industry.

• 수면정신생리
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• 제3권2호
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• pp.18-31
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• 1996

Jet-lag can be defined as the cumulative physiological and psychological effects of rapid air travel across multiple time zones. Many reports have suggested that age-related changes in sleep reflect fundamental changes in the circadian system and in significant declines in slow wave sleep. Jet lag is a dramatic situation in which the changes of the phase of circadian process and homeostatic process of sleep occur. Thus the authors evaluatead the changes of sleep-wake cycle from jet lag by age. Thirty-eight healthy travellers were studied for 3 days before and 7 days after jet-flights across seven to ten time zone. They were aged 19-70, They trareled eastbound, Seoul to North America (USA, Canada). Sleep onset time, wake-up time, sleep latency, awakening frequency on night sleep, awakening duration on night sleep, sleepiness at wake-up and nap length were evaluated. Our results suggest that by the 7 to 10 time zone shift, the old age group was significantly influenced in sleep-wake cycles. The date on which subjective physical condition was recovered was $6.23{\pm}83$ day after arrivals for old age group, while for young and middle age group, $4.46{\pm}1.50$ day and $4.83{\pm}1.52$ day, respectively. In old age group, sleep onset time was later than baselines and could not recover untill 7th day. But in other groups, the recovery was within 5th day. Nap dura fion was longer in old age group through jet lag than younger age group. In other parameters, there was no definite difference among three age groups. Our results suggested that the old age was significantly influenced by the disharmony between internal body clock and sleep-wake cycle needed at the travel site. Thus we proved that recovery ability from jet lag was age-dependent as well as travelling direction-dependent. To demonstrate more definite evidence, EEG monitoring and staging of sleep were funthun encouraged.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제6권2호
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• pp.244-253
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• 2000

병렬 컴퓨터의 메시지 전달에서 응용에 관계없이 일반적으로 우수한 경로 지정 및 스위칭 정책은 존재하지 않으므로, 사용자가 응용에 따라서 정책을 변경할 수 있게 하는 것이 바람직하다. 본 논문에서는 마이크로프로세서 구조에 기초한 경로 지정 엔진과는 달리, 성능의 감소 없이 융통성 있는 경로 지정과 스위칭 기능을 수행할 수 있는 조견표(look-up table) 경로 지정 엔진의 구현에 대하여 기술한다. 제안된 경로 지정 엔진은 조견표의 내용을 바꿈으로써 웜홀(wormhole), 가상 컷스루우(virtual cut-through) 및 패킷 스위칭(packet switching) 등은 물론, 다양한 경로 지정 알고리즘의 혼성(hybride)스위칭을 구현할 수 있다. 경로 지정 엔진의 조견표는 파이프라인 구조로 되어 있어, 하나의 플릿(flit) 정도의 저 지연을 가지므로, 단일 경로 지정 및 스위칭 정책을 하드와이어(hardwired)로 구현한 경우 보다 큰 성능의 감소 없이 다중의 경로 지정 동작을 중첩할 수 있다. 제안된 4개의 파이프 라인단은 해저드(hazard)를 일으키지 않으므로, 고 비용의 포워딩(forwarding) 회로가 필요 없다. 경로 지정 엔진은 시간공유의 컷스루우 버스나 크로스바(crossbar) 스위치를 갖는 단일 경로로 되어 있는 4개의 물리적 경로를수용할 수 있다. 제안된 경로 지정 엔진은 Xilinx 4000XL 시리즈 FPGA를 사용하여 구현되었다.

• 한국공간정보시스템학회 논문지
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• 제8권1호
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• pp.77-92
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• 2006

최근 모바일 환경의 급격한 발전으로 모바일 기기에서 지도를 표현하기 위한 필요성이 급증하고 있다. 본 논문은 모바일 환경에서 공간 데이터를 효율적으로 제공하기 위해 가장 중요한 역할을 담당하는 공간 데이터 관리자를 제안한 논문이다. 본 논문에서 제안하는 공간 데이터 관리자는 상호운용성을 지원하면서도 효율적인 성능을 제공하기 위하여 다양한 방법을 사용한다. 상호운용성을 지원하기 위해서는 국제 표준을 준수하여 상이한 환경에서도 재사용성을 보장한다. 성능 향상을 위해서는 물리적인 메인 메모리에 공간 데이터를 적재하고 서비스하여 디스크 접근 시간을 없애고, 결과 데이터 형식으로 미리 변환한 공간 데이터를 메인 메모리에 적재하여 형식 변환에 걸리는 시간이 필요 없도록 한다. 그리고, 모바일 환경에서 유무선 온라인으로 공간 데이터를 실시간으로 전송하는 경우에 전체 데이터를 전송하지 않고 부분적으로 전송된 데이터만으로도 표현이 가능하도록 하여 응답 시간 및 처리 시간을 최소화할 수 있도록 한다.

• 수면정신생리
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• 제2권2호
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• pp.146-155
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• 1995

Jet lag can be defined as the cumulative physiological and psychological effects of rapid air travel across multiple time zone. The consequences of jet lag include fatigue, general malaise, sleep disturbances, and reductions of cognitive and psychomotor performance, all of which have been documented in experimental biological and air crew personnel studies. Thus authors tried to study the jet lag of natural travellers by modified self reporting sleep log. Total 61 healthy travellers was studied for 3 days before and 7 days after jet-flights across seven to ten time zone. The eastbound travelling group was 38 persons, aged 19 -70 and westbound travelling group was 23 persons, aged 13 - 69. Sleep onset time, wake-up time, sleep latency, awakening frequency on night sleep, awakening duration on night sleep, sleepiness at wake-up and nap length were evaluated. Our results suggested that the 7 to 10 time zone shift gave significant influence to traveller's sleep-wake cycles. The date which subjective physical condition was recovered on was $5.16{\pm}1.50$ day after arrivals for eastbound, while for westbound, $4.91{\pm}1.62$ day. In eastbound travelling, sleep onset time became later than baselines and could not recover until 7th day. But in westbound, it became earlier than baseline and could recover until 6th day. The mean score of 24-hour sleepiness was greater in eastboumd than westbound. Therefore the eastbound travelling caused more sleep-wake cycle disturbance and daytime dysfunction than westbound travelling. In other parameters, there was no definite difference between east and westbound. From our results, it was suggested that the symptom severity of jet lag was dependent on the travelling direction. To demonstrate more definite evidence, large sized data collections and comparision by age difference were needed.

• International Journal of Internet, Broadcasting and Communication
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• 제10권3호
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• pp.26-34
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• 2018

In this paper, we propose a scheduling scheme that can efficiently serve I/O requests having deadlines in flash storage. The I/O requests with deadlines, namely, real-time requests, are assumed to be issued for streaming services of continuous media. Since a Web-based streaming server commonly supports downloads of HTMLs or images, we also aim to quickly process non-real-time I/O requests, together with real-time ones. For this purpose, we adopt the well-known rate-reservation EDF (RR-EDF) algorithm for determining scheduling priorities among mixed I/O requests. In fact, for the use of an EDF-style algorithm, overhead of task's switching should be low and predictable, as with its application of CPU scheduling. In other words, the EDF algorithm is inherently unsuitable for scheduling I/O requests in HDD storage because of highly varying latency times of HDD. Unlike HDD, time for reading a block in flash storage is almost uniform with respect to its physical location. This is because flash storage has no mechanical component, differently from HDD. By capitalizing on this uniform block read time, we compute bandwidth utilization rates of real-time requests from streams. Then, the RR-EDF algorithm is applied for determining how much storage bandwidth can be assigned to non-real-time requests, while meeting deadlines of real-time requests. From this, we can improve the service times of non-real-time requests, which are issued for downloads of static files. Because the proposed scheme can expand flexibly the scheduling periods of streams, it can provide a full usage of slack times, thereby improving the overall throughput of flash storage significantly.

• 한국통신학회논문지
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• 제31권11A호
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• pp.1101-1112
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• 2006

무선 환경에서의 이동 중 고속의 멀티미디어 서비스 제공에 대한 수요가 증가하면서 (Wireless Broadband internet) 시스템과 같은 MBWA (Mobile Broadband Wireless Access) 기술에 대한 관심이 점차 증가하고 있다. 이러한 WiBro 시스템은 기존의 셀룰라(Cellular) 시스템 기반의 이동 통신망과는 달리 기본적으로 IP 기반의 백본 네트워크로 구성될 것이며 ALL-lP로의 망 진화의 흐름에 따라서 궁극적으로는 IPv6 (IP version six) 기반의 백본 네트워크로 도입될 것이다. 이와 같은 무선 이동 환경에서는 WiBro 시스템의 물리 계층이나 매체 접근 제어 계층에서의 이동성 지원 방안뿐만 아니라 네트워크 계층에서의 이동성 지원 프로토콜 지원이 필요하다. 따라서 본 논문에서는 IPv6 기반의 WiBro 시스템에서 단말의 서브넷 (Subnet) 간 핸드오버 성능을 향상시키기 위한 고속 핸드오버 방안을 제안하고 모의실험을 통해서 제안한 메카니즘 (Mechanism)이 서브넷 간 핸드오버 시 발생할 수 있는 데이터 유실 문제와 핸드오버 지연 발생 문제 등을 개선할 수 있다는 것을 보인다.

• 한국컴퓨터정보학회논문지
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• 제24권5호
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• pp.49-58
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• 2019

In this paper, we propose an edge cloud platform architecture for implementing smart factory. The edge cloud platform is one of edge computing architecture which is mainly focusing on the efficient computing between IoT devices and central cloud. So far, edge computing has put emphasis on reducing latency, bandwidth and computing cost in areas like smart homes and self-driving cars. On the other hand, in this paper, we suggest not only common functional architecture of edge system but also light weight cloud based architecture to apply to the specialized requirements of smart factory. Cloud based edge architecture has many advantages in terms of scalability and reliability of resources and operation of various independent edge functions compare to typical edge system architecture. To make sure the availability of edge cloud platform in smart factory, we also analyze requirements of smart factory edge. We redefine requirements from a 4M1E(man, machine, material, method, element) perspective which are essentially needed to be digitalized and intelligent for physical operation of smart factory. Based on these requirements, we suggest layered(IoT Gateway, Edge Cloud, Central Cloud) application and data architecture. we also propose edge cloud platform architecture using lightweight container virtualization technology. Finally, we validate its implementation effects with case study. we apply proposed edge cloud architecture to the real manufacturing process and compare to existing equipment engineering system. As a result, we prove that the response performance of the proposed approach was improved by 84 to 92% better than existing method.

• 문화기술의 융합
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• 제7권1호
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• pp.558-563
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• 2021

양자점 셀룰라 오토마타(Quantum-Dot Cellular Automata)는 기존의 CMOS 회로의 물리적 크기 한계를 극복하여 효율적인 회로 설계가 가능할 뿐만 아니라 에너지 효율이 우수한 특징 때문에 많은 연구 단체에서 주목받고 있는 차세대 나노 회로 설계기술이다. 본 논문에서는 QCA를 이용하여 기존 디지털 회로 중 하나인 T 플립플롭 회로를 제안한다. 기존에 제안되었던 T 플립플롭들은 다수결게이트를 기반으로 설계되었기 때문에 회로가 복잡하며 지연시간이 길다. 따라서 다수결게이트를 최소화시키며, 셀 간 상호작용을 이용한 XOR 게이트 기반의 T 플립플롭을 설계함으로써 회로의 복잡도를 줄이고, 지연시간을 최소화한다. 제안하는 회로는 QCADesigner를 사용하여 시뮬레이션을 진행하며, 기존에 제안된 회로들과 성능을 비교 및 분석한다.

• PNF and Movement
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• 제18권3호
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• pp.393-401
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• 2020

Purpose: In recent years, there has been increasing interest in using blood flow-restricted exercise (BFRE) or KAATSU training. The KAATSU training method, which partially restricts arterial inflow and fully restricts venous outflow in the working musculature during exercise at reduced exercise intensities, has been proven to result in substantial increases in both muscle hypertrophy and strength. The purpose of this study was to investigate the proper level of pressure for KAATSU training using compound muscle action potential (CMAP) analysis. Methods: Twenty-two healthy adults voluntarily participated in this study. CMAP was conducted by measuring the terminal latency and amplitude using a motor nerve conduction velocity test. For reference-line, supramaximal electrical stimulation was applied to the median nerves of the participants to obtain CMAP for the abductor pollicis brevis. For baseline, the intensity of the electrical stimulation was decreased to a level at which the CMAP amplitude was about a third of the CMAP amplitude obtained by the supramaximal electrical stimulation. The pressure levels for the KAATSU were set as a systolic blood pressure (strong pressure), the median values of systolic and diastolic blood pressure (intermediate pressure), and diastolic blood pressure (weak pressure). In the KAATSU condition, CMAP was performed under the same conditions as baseline after low-intensity thumb abduction exercises were performed at the subjects' own pace for one minute. Results: As the pressure increased, the CMAP amplitude was significantly increased, signifying that more muscle fibers were recruited. Conclusion: This study found that KAATSU training recruited more muscle fibers than low-intensity exercise without the restriction of blood flow.