• Title/Summary/Keyword: frontal systems

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Distribution of Microzooplankton across the Frontal Systems of the Southern Ocean

  • Lee, Hak-Young;Cho, In-Sook;Kim, Jong-Won;Richard M. Greene
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • v.3 no.1
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    • pp.1-9
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    • 1999
  • Microzooplankton was analysed between $40^{\circ}s$ to $53^{\circ}s$S and $140^{\circ}E$ to $146^{\circ}E$ of the Sourthern Ocean from November 18 to November 30, 1995 to investigate the influence of frontal systems. The density and carbon biomass of microzooplankton were clearly associated with frontal systems, and at least 4 different communities were identified. The Subtropical Convergence Zone and Antarctic Polar Front Zone were the major biological boundaries recognized in the Southern Ocean. Ciliates predominated other microzooplankton in density and carbon biomass. Non-tintinnid ciliates occupied more than 70% of the total microzooplankton, and Laboea spp. was the major component of the non-tintinnid ciliates. The density and carbon biomass showed a decreasing tendency toward south from $40^{\circ}S$ to the $53^{\circ}S$ transect. The ecological importance of a frontal zone is confirmed by the microzooplanktonic data obtained from this study.

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Pipe Network Analysis by Using Frontal Solution Method (Frontal 기법을 이용한 상수관망의 흐름해석 모형)

  • 박재홍;한건연
    • Water for future
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    • v.29 no.1
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    • pp.141-150
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    • 1996
  • Steady state analysis of pressure and flow in water supply piping systems is a problem of great importance in hydraulic engineering. The basic equations consist of continuity equation and energy equation. The network equations are solved iteratively by using linear solution method. The resulting linear simultaneous equations are solved by frontal method. Frontal method, which is suitable to sparse matrix, gathers only non-zero entries in coefficient matrix. The suggested methodology can analyze faster than the existing routines by using smaller computer memory. The model presented in this study shows accurate and efficient results for various piping systems.

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Variations in Neural Correlates of Human Decision Making - a Case of Book Recommender Systems

  • Naveen Z. Quazilbash;Zaheeruddin Asif;Saman Rizvi
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.17 no.3
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    • pp.775-793
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    • 2023
  • Human decision-making is a complex behavior. A replication of human decision making offers a potential to enhance the capacity of intelligent systems by providing additional user assistance in decision making. By reducing the effort and task complexity on behalf of the user, such replication would improve the overall user experience, and affect the degree of intelligence exhibited by the system. This paper explores individuals' decision-making processes when using recommender systems, and its related outcomes. In this study, human decision-making (HDM) refers to the selection of an item from a given set of options that are shown as recommendations to a user. The goal of our study was to identify IS constructs that contribute towards such decision-making, thereby contributing towards creating a mental model of HDM. This was achieved through recording Electroencephalographic (EEG) readings of subjects while they performed a decision-making activity. Readings from 16 righthanded healthy avid readers reflect that reward, theory of mind, risk, calculation, task intention, emotion, sense of touch, ambiguity and decision making are the primary constructs that users employ while deciding from a given set of recommendations in an online bookstore. In all 10 distinct brain areas were identified. These brain areas that lead to their respective constructs were found to be cingulate gyrus, precentral gyrus, inferior parietal lobule, posterior cingulate, medial frontal gyrus, anterior cingulate, postcentral gyrus, superior frontal gyrus, inferior frontal gyrus, and middle frontal gyrus (also referred to as dorsolateral prefrontal gyrus (DLPFC)). The identified constructs would help in developing a design theory for enhancing user assistance, especially in the context of recommender systems.

Neurochemical Studies of Standardized Ginseng Extract G115 on the Central Dopaminergic Activity (II) (표준화된 인삼추출물 G115의 중추도파민신경계에 대한 신경화학적 연구(II))

  • 이순철;유관희;김용호
    • Journal of Ginseng Research
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    • v.16 no.3
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    • pp.183-189
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    • 1992
  • Effect of the standardized ginseng extract(G115) on the central monoaminergic systems were investigated in comparison with that of halcperidol in rats. Immediately after sacrificed by decapitation, the strlata and frontal cortex were removerl. Concentations of the monoamines dopamine and serctorLin and their metabolites were deterinintd by HPLC-EC. G115 increased the concentration of 5-HIAA and DOPAC/UA ratio in striatum. However, dopaminrrgic neuronal activities were not affected by G115 that decreased the concentratio,Is of 5-HT and 5-HIAA in frontal cortex. G115 in combination with apomorphine significantly irlcreased the concentration of DA and S-HT but decreased the DO PAC/DA ratio and 5-HIAA/5-HT ratio only in frontal cortex. These results suggest that G115 like HPD inhibits the activity of nigrostriatal dopamine neuron in striatum. However, unlike HPD it activates central monoaminergic neuron activity in frontal cortex.

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Frontal Plane Motion with Pelvis and Waist Joint Rotations in Bipedal Walking

  • Ha, Tae-Sin;Kim, Joo-Hyung;Choi, Chong-Ho
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.2248-2253
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    • 2005
  • Although the progress in bipedal walking is impressive in recent years, biped robots still require very high torque and can walk only for a short time interval with their internal batteries. Therefore, further research needs to be carried out to enhance walking efficiency of these robots. In order to achieve this goal, we attempt to imitate human walking with pelvis and waist joint rotations in the frontal plane. In order to investigate the effect of the pelvis and waist joint rotations in the frontal plane motion, we study the frontal plane model with a triangular structure made up of a waist joint and two hip joints. Through simulation, we show that the pelvis rotation can reduce the maximum torque and the control effort, and the waist joint rotation can reduce the trunk sway caused by the pelvis rotation. The combination of these two rotations makes the bipedal walking in the frontal plane more efficient.

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Effectiveness of a Vehicle Restraint System in Frontal Crash (정면 충돌시 차량 구속 시스템의 효과)

  • Lee, Dong-Jae;Oh, Kwang-Seok;Son, Kwon
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.314-314
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    • 2000
  • This study deals with the analysis of the effectiveness of a safer belt in frontal crash. ATB, Articulated Total Body, program is used as a dynamics solver of the occupant model. ATB is a public code, however, the program is somewhat cumbersome to use due to lack of sufficient user interface. A preprocessor and a postprocessor are, therefore, developed for a user friendly graphic interface in Windows environment. Dialog boxes are used for an interface with GEBOD, Generator of Body Data, for human anthropometry and with ADAMS for vehicle dynamics. It is found through three test simulations that simulated results are in good agreement with those obtained by ATB. The effect of the initial slack of safety belt is investigated for frontal crash using the developed program.

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A Study on the Comparison for the Child Occupant Safety from Frontal Crash Test Protocol (정면충돌 시험방법에 따른 어린이 탑승객 충돌안전성 비교연구)

  • Kim, Siwoo
    • Journal of Auto-vehicle Safety Association
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    • v.8 no.3
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    • pp.33-38
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    • 2016
  • Recently, development in vehicle safety could increase interest in children's safety in vehicle collisions. But the research of children safety in vehicle collisions is not being conducted as many as that of adult's. Especially the study for the vehicle crash was not much. This study focused on the comparison of child safety between test protocols to evaluate children's safety in crash test. Injuries of Q6 and Q10 dummy were evaluated using FFRB (Full frontal rigid barrier) test and 40% ODB (Offset deformable barrier) test with one model vehicle. Even though the limit number of test, the tendency of injury criteria of Q6 and Q10 dummy between the test protocols was not conformed but injury criteria of Q6 and Q10 were not same between FFRB and 40% ODB.

The Study on the Effect of Seatbelt anchorage points using Q6 in sled test (좌석안전띠 부착장치 위치에 따른 어린이 충돌안전성 연구)

  • Kim, Siwoo;Ryu, Hyun;Kim, Yonggil;Baek, Seonhyeon;Kim, Minwoo;Park, Jihun
    • Journal of Auto-vehicle Safety Association
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    • v.6 no.2
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    • pp.49-54
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    • 2014
  • Development in vehicle industry could increase interest in children's safety recently. However the research of children safety is not being conducted as many as that of adult's. Especially the basic study for the vehicle crash on-board children was not much. This study focused on the effect of seatbelt anchorage points to evaluate children's safety in frontal crash. The current regulation of the seatbelt anchorage points is suitable for ranged from female 5% to male 95%. The assessment of children's safety at buckle up of no used CRS(child restraint system) was performed using frontal sled tests. The frontal crash pulse in sled tests was designed to the average of about 30 KNCAP frontal crash pulses. To reduce number of experiments, DOE is used. The Q6 child dummy and standard seat in UN R 129 were used. According to the analysis of test results, children's safety has been influenced by the points of seatbelt anchorage.

A Study on the Injury Criteria of the Occupant Protection Performance of Crush Cushions (충격흡수시설의 탑승자보호 성능평가 기준에 관한 연구)

  • Lim, Jae-Moon;Jung, Geun-Seup
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.2
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    • pp.49-57
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    • 2008
  • The performance of crash cushion systems is certified through the full scale crash tests by the standard for installation and maintenance guidelines for roadside safety appurtenance. The impact severities of impacting vehicles in collision with crash cushion systems are rated by indices THIV and PHD. Crash test results are considered to study the performance of three crash cushion systems. In case of the frontal impact or the offset frontal impact, the results show that THIV values of three systems are very close to the threshold limit for the occupant protection. Also, the results show that PHD would be improper for the occupant protection performance index. In order to improve the occupant protection performance of crash cushions, ASI needs to be included in the impact severity index.

Ginsenoside Rb1 Modulates Level of Monoamine Neurotransmitters in Mice Frontal Cortex and Cerebellum in Response to Immobilization Stress

  • Lee, Sang-Hee;Hur, Jin-Young;Lee, Eun-Joo H.;Kim, Sun-Yeou
    • Biomolecules & Therapeutics
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    • v.20 no.5
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    • pp.482-486
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    • 2012
  • Cerebral monoamines play important roles as neurotransmitters that are associated with various stressful stimuli. Some components such as ginsenosides (triterpenoidal glycosides derived from the Ginseng Radix) may interact with monoamine systems. The aim of this study was to determine whether ginsenoside Rb1 can modulate levels of the monoamines such as dihydroxyphenylalanine (DOPA), dopamine (DA), norepinephrine (NE), epinephrine (EP), 3,4-dihydroxyphenylacetic acid (DOPAC), 5-hydorxytryptamine (5-HT), 5-hydroxindole-3-acetic acid (5-HIAA), and 5-hydroxytryptophan (5-HTP) in mice frontal cortex and cerebellum in response to immobilization stress. Mice were treated with ginsenoside Rb1 (10 mg/kg, oral) before a single 30 min immobilization stress. Acute immobilization stress resulted in elevation of monoamine levels in frontal cortex and cerebellum. Pretreatment with ginsenoside Rb1 attenuated the stress-induced changes in the levels of monoamines in each region. The present findings showed the anti-stress potential of ginsenoside Rb1 in relation to regulation effects on the cerebral monoaminergic systems. Therefore, the ginsenoside Rb1 may be a useful candidate for treating several brain symptoms related with stress.