• Title/Summary/Keyword: Power-level control

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Development of Rubber Damper of Flywheel for Diesel Engine (디젤기관(機關) 플라이휠의 고무댐퍼 개발(開發))

  • Myung, Byung Soo;Kim, Sung Rai
    • Korean Journal of Agricultural Science
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    • v.20 no.1
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    • pp.68-87
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    • 1993
  • Data acquisition system and computer program developed in this study could be well used in engine vibration analysis. The system and program developed were also operated to be able to control measuring interval, number of channels, number of data. The flywheel was specially studied to provide the proper weight with rubber damper for the engine design at low level of vibration. This study was conducted to obtain basic data which affect the engine vibration. The experiment of this study was performed on original weight flywheel, weight-reduced flywheel, weight-reduced and rubber-coated flywheel, weight-reduced and damper-attached flywheel. Avarage of peak value, maximum vibration, power spectrum density based on FFT analysis are major factors of this experiment. Results were obtained as follows : 1. When rubber was inserted in the flywheel rim of which weight was reduced from 32.2kgf to 24.4kgf, maximum vibration of the engine was decreased 48.3% at X axis, 35.5% at Y axis and 34.6% at Z axis in comparison with the flywheel of original weight. 2. When the flywheel of rubber damper was compared with the original flywheel, the average of absolute vibration for rubber damped flywheel was decreased at X, Y, Z axis and especially its decreasing rate was so high at X-axis comparing with the other flywheel, which implied that rubber damper was very useful to reducing the vibration of the engine at X axis. 3. Hysteresis losses of X, Y, Z axis were greatly decreased in the flywheel with rubber damper on rim. 4. Damped oscillation effect on X and Y axis vibration above average peak vibration by the flywheel of rubber damper on rim was larger than those by the other flywheels. 5. Power spectrums of vibration at real and imaginery part were bi-mode type. The vibration frequency of rubber dampered flywheel which weight is decreased was slightly increased as compared with original flywheel.

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The Use of National Names for International Bodies of Water: Critical Perspective (공해(公海)에 대한 국가지명 사용: 비판적 관점)

  • 알렉산더B.머피
    • Journal of the Korean Geographical Society
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    • v.34 no.5
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    • pp.507-516
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    • 1999
  • More than twenty-five major international bodies of water bear the names of particular nations or states. Many of these are not names are widely accepted, but considerable disagreement has developed in some cases. A systematic examination of the level of conflict over the use of national names for international bodies of water indicates that conflict is most likely to develop where shifting power relations among interested states produce concern about the hegemonic ambitions of the state after which the body of water is named. This is the case in the three situations where considerable contention exists over the use of a national name for an international body of water: the Persian Gulf/Arabian Sea, the Sea of Japan/East Sea, and the South China SealBien Dong. Cases evidencing little contention are those where either no state has a significant interest in the naming issue, or where the name that is attached to the body of water is that of a state that has not been a historic threat to others in the region. Naming international bodies of water after nations or states is potentially problematic because such appellations can connote ownership or control by a single people or political entity. An understanding of the controversies surrounding these place names requires consideration of the geopolitical context in which they are embedded.

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The Hope of the Stroke Patients (뇌졸중환자의 희망)

  • 김이순
    • Journal of Korean Academy of Nursing
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    • v.27 no.1
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    • pp.212-227
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    • 1997
  • Cerebrovascular diseases in Korea is an important health problem since mortality and mobidity have been increased rapidly. It marked the 2nd cause of specific death rates in 1993. The stroke causes physical function disorder due to hemiparalysis and emotional disorder, and stroke patients experience helplessness, powerlessness. sense of alienation and loss of hope. These feelings make the rehabilitation difficult because they lose the will of life. The subjects of the study were seven citizens who live in Pusan, are over 50 years old and belong to low income-level. The data were collected from Jan. to Sep. 1995. The researcher as a caregiver and volunteer made confidence of them and asked for their agreement on the purpose of the study. The subjects expressed their experience as openheartedly as possible. The analysis of the data was made through the phenomenological analytic method suggested by Giorgi, which is as follows ; as an unit of description which include the subject' expressions and the researcher's observation, it is examined the theme that express the hope experience with the subject's language(underlining), and the focal meanings are identified. The focal meaning is the crystalization of the theme, which is written in the language of the researcher. After intergrating the focal meaning and make the situated structural description as the meaning of the hope experience identified on each subject's point. After intergrating the situated structural description and make the general structural description as the meaning of the hope experience identified on total subject's point then the systemizing of the structure of the hope experienced phenomena and the flowing of the conciousness was researched. The conclusions of this study was as follows : The ten sources of hope which the subjects experienced were sorted as under 〈mutual relations to others : spouse, children, relatives, fellow believer. health professioner. associate patient group〉, 〈spiritual dependence〉. 〈recovery of physical function〉. 〈rumination of the past life〉, 〈expectation of the future〉. 〈economic power〉, 〈belief〉, 〈ability〉. 〈spontaneous participation〉 and 〈recovery of roles〉. Their hope was spoken out by the following two kinds of linguistics. First. the hope was expressed in the affirmative expression as follows : 〈 to be dependable〉, 〈to make efforts〉, 〈to keep under control〉, 〈to desire〉, 〈to be pleasant〉, 〈to be peaceful〉, 〈to be grateful〉, 〈to give help〉, 〈self-confidence. Courage〉, 〈to be happy〉, 〈to satisfy oneself〉, 〈to share with others〉, 〈to understand〉 and 〈to be affected, be impressed〉 Second, the hope was expressed in the negative on pression as under : 〈to be distressed〉, 〈to be uneasy〉, 〈to be sorry, be unsatisfied〉 〈despair〉, 〈to abandon〉, 〈to be fearful〉, 〈to suffer〉, 〈to bear a burden〉 〈to be confused〉, 〈to be solitary〉, 〈chest trouble〉, 〈to feel heavy〉 〈grief〉, 〈to be daunted〉, 〈to get angry〉, 〈to be uncomfortable〉, 〈to have something regretable〉 and 〈to feel guilty〉. And their hope was expressed by the following four behavioral expressions : 〈physical sphere〉, 〈psychological sphere〉, 〈social support sphere〉 and 〈spiritual sphere〉. The reaction patterns of their hope experience appeared in the following 4 coping method : 〈conquest type〉, 〈dependence type〉, 〈adaptation type〉 and 〈fate type〉. Finally, in the hope structure the sense of certainty don't always coexict with the sense of uncertainty, When the stroke patients try to search for the best quality of life, the senses of certainty and uncertainty make a continual cyclic system in the hope structure.

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Quality Characteristics of Sea Tangle Single Cell Detritus (SCD) Manufactured by Vibrio sp. Isolated from Batillus cornutus (소라에서 분리한 Vibrio균으로 제조한 다시마 Single Cell Detritus(SCD)의 품질특성)

  • Bang, Sang-Jin;Shin, Il-Shik;Kim, Sang-Moo
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.5
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    • pp.606-612
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    • 2006
  • Obtaining powder form of seaweed is essential for the use of seaweed as a food additive. The deterioration of seaweed caused by high temperatures during homogenization and powder processing is a serious problem and limits the use of seaweed as a food or pharmaceutical ingredient. Furthermore, many powder particles are not fluidized very well because of the interaction between particles. In order to solve this problem, sea tangle was hydrolyzed to a level of single cell detritus (SCD) by Vibrio sp., isolated from Batillus cornutus. with strong hydrolytic activity. The crude protein and amino acid contents of sea tangle SCD were higher than those of the powder, whereas the reverse was true for ash content. Sea tangle powder contained more mineral than its SCD, whereas total amino acid content was 5 times more in SCD than in power. The anticancer activities of sea tangle SCD and powder were 31.20 and 29.07%, respectively, with no significant difference (p<0.05), but about 15% higher than that of the control. The ACE inhibitory activity of the sea tangle powder, 39.31%, was higher than the 26.07% of the SCD. The antithrombin activity of the sea tangle powder, 55.3 seconds, was higher than the 34.5 seconds of the SCD. Moreover, there was no antioxidative and ischemic activities in both tile sea tangle powder and SCD.

Comparison of Rice Properties Between Rice Grown Under Conventional Farming and One Grown Under Eco-Friendly Farming Using Hairy Vetch (친환경 무농약 재배와 관행 재배 쌀의 특성비교)

  • Lee, Seung-Hyun;Kim, Min-Young;Kim, Han-Yong;Ko, Sang-Hoon;Shin, Mal-Shick
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.39 no.11
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    • pp.1684-1690
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    • 2010
  • The properties of non-waxy rice, Dongjin 1, cultivated with conventional farming (CF) and environmentally-harmonized farming (EHF) using hairy vetch were compared to determine rice water absorption, physicochemical and pasting properties, antioxidant activities of brown and white rice, and a sensory evaluation of cooked white rice was carried out. EHF was treated with green manure crops such as hairy vetch and chitinase, which produce microorganism culture solution. CF was applied with seed disinfection treatments, fertilizer herbicides, and agricultural chemicals for the control of pests and diseases. The absorption level of EHF rice was higher than that of CF rice grain, regardless of the cultivation methods used. The ash and crude lipid contents were higher, but protein and dietary fiber contents were lower in the CF rice than in the EHF rice. The total starch content, water binding capacity, and swelling power of white rice were higher than those of brown rice, regardless of the cultivation methods used. The DPPH's antioxidant activity was shown as follows: EHF brown rice, EHF white rice and CF rice, in a decreasing order. The initial pasting temperature of EHF rice was lower than that of CF rice, but the peak, cold, and breakdown viscosities exhibited reverse trends. The sensory evaluation showed that the cooked white rice cultivated with EHF was not significantly different from that cultivated with CF (p<0.05). The overall preference of cooked rice did not show significant differences between the two cultivation methods (p<0.05).

An Improvement of Stochastic Feature Extraction for Robust Speech Recognition (강인한 음성인식을 위한 통계적 특징벡터 추출방법의 개선)

  • 김회린;고진석
    • The Journal of the Acoustical Society of Korea
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    • v.23 no.2
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    • pp.180-186
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    • 2004
  • The presence of noise in speech signals degrades the performance of recognition systems in which there are mismatches between the training and test environments. To make a speech recognizer robust, it is necessary to compensate these mismatches. In this paper, we studied about an improvement of stochastic feature extraction based on band-SNR for robust speech recognition. At first, we proposed a modified version of the multi-band spectral subtraction (MSS) method which adjusts the subtraction level of noise spectrum according to band-SNR. In the proposed method referred as M-MSS, a noise normalization factor was newly introduced to finely control the over-estimation factor depending on the band-SNR. Also, we modified the architecture of the stochastic feature extraction (SFE) method. We could get a better performance when the spectral subtraction was applied in the power spectrum domain than in the mel-scale domain. This method is denoted as M-SFE. Last, we applied the M-MSS method to the modified stochastic feature extraction structure, which is denoted as the MMSS-MSFE method. The proposed methods were evaluated on isolated word recognition under various noise environments. The average error rates of the M-MSS, M-SFE, and MMSS-MSFE methods over the ordinary spectral subtraction (SS) method were reduced by 18.6%, 15.1%, and 33.9%, respectively. From these results, we can conclude that the proposed methods provide good candidates for robust feature extraction in the noisy speech recognition.

Inhibitory Effect of Perilla Sprouts Extracts on Oxidation of Perilla Oil (들깨유의 산화에 대한 들깨 발아 싹 추출물의 억제효과)

  • Kim, Seok-Joong
    • Journal of the Korean Applied Science and Technology
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    • v.29 no.2
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    • pp.330-338
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    • 2012
  • During 10 days germination of perilla seeds for sprouts preparation, the changes of proximate composition and antioxidant activities were monitored, and the inhibitory effect of sprouts extracts on perilla oil oxidation was also studied. The moisture content in seeds(2.9%) was increased to 9.2% in sprouts at 10 days while crude ash content wasn't significantly. The crude fat and protein contents were reduced from 46.8% and 20.7% in seeds to 18.2% and 18.3% in sprouts, respectively, but reducing sugar and fiber contents increased from 2.2% and 14.8% to 12.8% and 22.4%, respectively. Compared with perilla leaf, sprouts at 10 days contained more fat, carbohydrate, reducing sugar, and fiber while less moisture, ash, and protein. Antioxidant activities during germination were increased and reached to maximum at 8 days in which Trolox equivalent antioxidant capacity(TEAC) based on DPPH and ABTS radical scavenging were 133.1 and 136.8 Trolox eq. mmol/kg, respectively, and ferric ion reducing power(FRAP) was 399.3 Fe(II) eq. mmol/kg. Polyphenol content(19.2 g/kg) was maximum at this stage, too. Perilla leaf showed similar TEAC but higher FRAP than the sprouts. When methanol extract of sprouts at 8 days was added to perilla oil, the oil oxidation was delayed in dose dependent manner. The induction time for oxidation was extended about 2.8 times by adding 2.5%(w/w) extract, that is, from 1.67 hr(control) to 4.62 hr. This induction time corresponded to 38% level of that of perilla oil containing 2.5% BHT.

Design and Implementation of FMCW Radar Signal Processor for Drone Altitude Measurement (드론 고도 측정용 FMCW 레이다 신호처리 프로세서 설계 및 구현)

  • Lim, Euibeen;Jin, Sora;Jung, Yongchul;Jung, Yunho
    • Journal of Advanced Navigation Technology
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    • v.21 no.6
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    • pp.554-560
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    • 2017
  • Accurate altimetry is required for the reliable flight control of drones or unmanned air vehicles (UAVs), and the radar altimeter is commonly used owing to its accuracy for the ground level. Due to the limitation for size, weight and power consumption, the frequency modulated continuous wave (FMCW) radar is appropriate for drone because it has lower complexity than that of pulse Doppler (PD) radar. Especially, fast-ramp FMCW radar, which transmits linear FM signal during very short period, is generally utilized, because it is robust for the ego-motion of drone. Therefore, we present the design and implementation results of the radar signal processor (RSP) for fast-ramp FMCW radar system. The proposed RSP was designed with Verilog-HDL and implemented with Altera Cyclone-IV FPGA device. Implementation results show that the proposed RSP includes 27,523 logic elements, 15,798 registers and memory of 138Kbits and can measure the altimeter at the rate of 100Hz with the operating frequency of 50MHz.

A Study on Scientific Thinking of Korean High School Students-With Reference to Logical Thinking and Reasoning Power- (고교생의 과학적 사고력에 관한 연구-논리적 사고와 추리력을 중심으로-)

  • Hwang, Keung-Yeon;Park, In-Keun;Kim, Tai-Sung
    • Journal of The Korean Association For Science Education
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    • v.9 no.1
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    • pp.19-37
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    • 1989
  • The purpose of this study was to investigate the development of logical thinking and scientific reasoning pattern of Korean high school students. To carry out this study subjects were selected about 2,000 Junior high school students, and about 4,100 senior high school students throughout the nation. They were identified as concrete, transitional or formal operational stage with the use of TOLT(the Test of Logical Thinking) by Tobin and Capie(1980), and TOSR(the Test of Scientific Reasoning) by W.A Farmer(1986). This study turned out that more than 76% of Junior high school students were classified as the concrete operational stage and about 44% of senior high school students were classified as the formal operational stage, while about 26% of them were still in the concrete operational level. This study showed that the main factor of the intellectual development of students is learning by the gradual advancement of their grades and especially entrance into the senior high school rather than by the physical growth. This study also showed that there are the take-off stage of the development of logical thinking between fourteen and fifteen years of their ages. Less than 25% of junior high school students were in the formal operational stages which are capable of control of variables, probabilistic, correlation and combinational logic in problem-solving situation, while 33-54% of senior high school students were in the formal operational levels. 38% of junior high school students were in the formal operational stage which is capable of proportional logic, while about 55% of senior high school students were in the formal operational stage. Less than 20% of senior high school students were classified as group of highly capable of scientific reasoning, while more than 23% of them were classified as group of poor capability. It also turned out that there are differences or no differences between male and female students of each school in problem-solving situation regarding each logic approach. These differences were proved to be fluctuating depending on the situations and their grades. The other results of this study is similar to those of other researches such as Tomlinson-Keasey 1972, Coleman 1973, Lawson 1973, Lawson and Renner 1974, Neimark 1975, Han 1982, and Kim 1989.

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A Design and Implementation of Mobile Logistics Information System (모바일 물류정보시스템 설계 및 구현)

  • Lee, Won-Joo;Lee, Sang-Jun;Lim, Heon-Yong;Kim, Chang-Hyeon
    • Journal of the Korea Society of Computer and Information
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    • v.17 no.7
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    • pp.139-146
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    • 2012
  • In this paper, we implement an m-LIS(Mobile-Logistics Information System) for an effective logistics management in consideration of logistics process and work environment. The m-LIS could perform the entire business process every minute and promote the work efficiency by tying up with ERP and POS system. Moreover, this system could enhance the management level of service and supply chain. Due to the reason that the existing logistics business was not computerized and automated, most of operation was accomplished by means of workers experience and convention. This problem brought about both the ineffective management and logistics quality deterioration by weakening the control power of the logistics site. In order to solve this problem, we put focus on providing the real-time operation monitoring environment on the spot, the satisfaction of the efficiency on the spot, and the optimized system by building up the logistics information system. Furthermore, we attest that the new logistics system could properly cope with the increase of the quantity of goods transported owing to stable logistics information support and the market expansion and growth caused by the firm interface between the new ERP and its related system.