• Title/Summary/Keyword: Behavioral tests

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Analysis of Reinforcement Effect of Hollow Modular Concrete Block on Sand by Laboratory Model Tests (실내모형실험을 통한 모래지반에서의 중공블록 보강효과 분석)

  • Lee, Chul-Hee;Shin, Eun-Chul;Yang, Tae-Chul
    • Journal of the Korean Geotechnical Society
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    • v.38 no.7
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    • pp.49-62
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    • 2022
  • The hollow modular concrete block reinforced foundation method is one of the ground reinforcement foundation methods that uses hexagonal honeycomb-shaped concrete blocks with mixed crushed rock to reinforce soft grounds. It then forms an artificial layered ground that increases bearing capacity and reduces settlement. The hollow modular honeycomb-shaped concrete block is a geometrically economical, stable structure that distributes forces in a balanced way. However, the behavioral characteristics of hollow modular concrete block reinforced foundations are not yet fully understood. In this study, a bearing capacity test is performed to analyze the reinforcement effectiveness of the hollow modular concrete block through the laboratory model tests. From the load-settlement curve, punching shear failure occurs under the unfilled sand condition (A-1-N). However, the filled sand condition (A-1-F) shows a linear curve without yielding, confirming the reinforcement effect is three times higher than that of unreinforced ground. The bearing capacity equation is proposed for the parts that have contact pressure under concrete, vertical stress of hollow blocks, and the inner skin friction force from horizontal stress by confining effect based on the schematic diagram of confining effect inside a hollow modular concrete block. As a result of calculating the bearing capacity, the percentage of load distribution for contact force on the area of concrete is about 65%, vertical force on the area of hollow is 16.5% and inner skin friction force of area of the inner wall is about 18.5%. When the surcharge load is applied to the concrete part, the vertical stress occurs on the area of the hollow part by confining effect first. Then, in the filled sand in the hollow where the horizontal direction is constrained, the inner skin friction force occurs by the horizontal stress on the inner wall of the hollow modular concrete block. The inner skin friction force suppresses the punching of the concrete part and reduces contact pressure.

The effect of semantic categorization of episodic memory on encoding of subordinate details: An fMRI study (일화 기억의 의미적 범주화가 세부 기억의 부호화에 미치는 영향에 대한 자기공명영상 분석 연구)

  • Yi, Darren Sehjung;Han, Sanghoon
    • Korean Journal of Cognitive Science
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    • v.28 no.4
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    • pp.193-221
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    • 2017
  • Grouping episodes into semantically related categories is necessary for better mnemonic structure. However, the effect of grouping on memory of subordinate details was not clearly understood. In an fMRI study, we tested whether attending superordinate during semantic association disrupts or enhances subordinate episodic details. In each cycle of the experiment, five cue words were presented sequentially with two related detail words placed underneath for each cue. Participants were asked whether they could imagine a category that includes the previously shown cue words in each cycle, and their confidence on retrieval was rated. Participants were asked to perform cued recall tests on presented detail words after the session. Behavioral data showed that reaction times for categorization tasks decreased and confidence levels increased in the third trial of each cycle, thus this trial was considered to be an important insight where a semantic category was believed to be successfully established. Critically, the accuracy of recalling detail words presented immediately prior to third trials was lower than those of followed trials, indicating that subordinate details were disrupted during categorization. General linear model analysis of the trial immediately prior to the completion of categorization, specifically the second trial, revealed significant activation in the temporal gyrus and inferior frontal gyrus, areas of semantic memory networks. Representative Similarity Analysis revealed that the activation patterns of the third trials were more consistent than those of the second trials in the temporal gyrus, inferior frontal gyrus, and hippocampus. Our research demonstrates that semantic grouping can cause memories of subordinate details to fade, suggesting that semantic retrieval during categorization affects the quality of related episodic memory.

Comparison of growth and neuropsychological function after treatment for hematologic and oncologic diseases in monozygotic twins (일란성 쌍생아에서 혈액 및 종양 질환 치료 후 성장 및 정신신경학적 발달에 대한 비교연구)

  • Kim, Gi Hwan;Kook, Hoon;Baek, Hee Jo;Han, Dong Kyun;Song, Eun Song;Jo, Young Kook;Choi, Ic Sun;Kim, Young Ok;Kim, Chan Jong;Woo, Young Jong;Yang, Soo Jin;Hwang, Tai Ju
    • Clinical and Experimental Pediatrics
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    • v.50 no.2
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    • pp.182-189
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    • 2007
  • Purpose : The primary purpose of this study was to evaluate the growth and neuropsychologic function following treatments for pediatric hematologic and oncologic diseases. Healthy monozygotic twins served as ideal controls for comparison to exclude possible confounding factors. Methods : Seven children treated with various hematologic and oncologic diseases were included in the study: acute lymphoblastic leukemia (ALL; n=2), Diamond-Blackfan anemia twins (n=2), and aplastic anemia (n=3). The median age at the diagnosis was 5.2 (0.3-15) years. The median duration of follow-up was 7.2 (4.9-10) years. Controls were healthy monozygotic twins. Growth was measured and the percentile channels were evaluated sequentially for patients. The K-WISC III was applied and compared in 5 pairs of patients and controls. Results : Similar growth profiles were noted for the twins. The percentiles at diagnosis was 3-10 in 3, 25-50 in 2, and 50-75 in 2 cases. All patients stayed in their growth percentiles through follow-up, except for 1 patient who became obese. For IQ tests, the mean behavioral, verbal and full scale IQ scores of patients were 88.0, 93.8, and 89.8, respectively, and those from their corresponding controls were 92.2, 97.0, and 91.7 (P>0.05). However, 2 children who were treated for ALL had lower IQ scores. Conclusion : Similar growth profiles were observed in the monozygotic twins in terms of height and weight. The IQ scores of patients were similar to those of monozygotic twins. However, prophylactic CNS-directed therapy for leukemia might adversely affect the IQ scores. A further prospective study on larger number of twins is warranted.

A Case of Childhood Obstructive Sleep Apnea Syndrome with Co-morbid Attention Deficit Hyperactivity Disorder Treated with Continuous Positive Airway Pressure Treatment (지속적(持續的) 상기도(上氣道) 양압술(陽壓術)을 시행(施行)하여 치료효과(治療效果)를 본 주의력(注意力) 결핍(缺乏).과잉(過剩) 운동장애(運動障碍)를 동반(同伴)한 소아기(小兒基) 폐쇄성(閉鎖性) 수면무호흡증(睡眠無呼吸症) 1례(例))

  • Sohn, Chang-Ho;Shin, Min-Sup;Hong, Kang-E;Jeong, Do-Un
    • Sleep Medicine and Psychophysiology
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    • v.3 no.1
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    • pp.85-95
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    • 1996
  • Obstructive sleep apnea syndrome(OSAS) in childhood is unique and different n-om that in adulthood in several aspects, including pathophysiology, clinical features, diagnostic criteria, complications, management, and prognosis. Characteristic features of childhood OSAS in comparison with the adult form are the variety of severe complications such as developmental delay, more prominent behavioral and cognitive impairments, vivid cardiovascular symptoms, and increased death risk, warranting a special attention to the possible diagnosis of OSAS in children who snore. However, the childhood OSAS is often neglected and unrecognized. We, therefore, report a case of very severe OSAS in a 5-year-old boy who was sucessfully treated with continuous positive airway pressure(CPAP) treatment. Interestingly, the patient was comor-bid with the attention deficit hyperactivity disorder. Prior to the initial visit to us, adenotonsillectomy had been done at the age of 4 with no significant improvement of apneic symptoms and heavy snoring. On the initial diagnostic procedures, marked degree of snoring was audible even in the daytime wake state and the patient was observed to be very hyperactive. Increased pulmonary vascularity with borderline cardiomegaly was noted on chest X-ray. The baseline polysomnography revealed that the patient was very sleep-apneic and snored very heavily, with the respiratory disturbance index(RDI) of 46.9 per hour of sleep, the mean SaO2 of 78.8%, and the lowest SaO2 of 40.0%(the lowest detectable oxygen level by the applied oxymeter). The second night polysomnography was done for CPAP titration and the optimal pressure turned out to be $8.0\;cmH_2O$. The applied CPAP treatment was well tolerated by the patient and was found to be very effective in alleviating heavy snoring and severe repetitive sleep apneas. After 18 months of the CPAP treatment, the patient was followed up with nocturnal polysomnography(baseline and CPAP nights) and clinical examination. Sleep apneas were still present without CPAP on the baseline night. However, the severity of OSAS was significantly decreased(RDI of 15.7, mean SaO2 of 96.2%, and the lowest SaO2 of 83.0%), compared to the initial polysomnographic findings before initiation of long-term CPAP treatment. Wechsler intelligence tests done before and after the CPAP treatment were compared with each other and surprising improvement of intelligence(total 9 points, performance 16 points) was noted. Clinically he was found to be markedly improved in his attention deficit hyperactive behavior after CPAP treatment, but with minimal change of TOVA(test of variables of attention) scores except conversion of reaction time score into normal range. On the chest X-ray taken after 18 months of CPAP application, the initial cardiopulmonary abnormalities were not found at all. We found that the CPAP treatment in a young child is very effective, safe, and well-tolerated and also improves the co-morbid attention deficit hyperactive symptoms. Overall, the growth and development of the child has been facilitated with the long-term use of CPAP. Cardiovascular complications induced by OSAS have been also normalized with CPAP treatment. We suggest that early diagnosis and active treatment intervention of OSAS in children are crucial in preventing and ameliorating possible serious complications caused by repetitive sleep apneas and consequent hypoxic damage during sleep.

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The Effects of Modafinil on Clinical Features and Sleep Structure of Narcolepsy Patients and Healthy Controls (모다피닐이 기면병 환자와 대조군의 임상 양상과 수면구조에 구조에 미치는 영향)

  • Shin, Hong-Beom;Jeong, Do-Un;Kim, Eui-Joong
    • Sleep Medicine and Psychophysiology
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    • v.13 no.2
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    • pp.67-74
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    • 2006
  • Introduction: Excessive daytime sleepiness and cataplexy are key features of narcolepsy. Modafinil is psychostimulant used in the treatment of narcolepsy. In this study, we evaluated effects of modafinil on nocturnal sleep structure and sleep latency in multiple sleep latency test and clinical features. Methods: Twelve narcoleptic patients (7 male, age: $22.9{\pm}2.6\;yrs$) were participated in the study. All of them had done nocturnal polysomnography (nPSG), multiple sleep latency test (MSLT), clinical symptoms scales and have repeated same procedure after taking 200 mg of modafinil. We have done linear mixed model analysis to describe effects of group, medication and nap time on these measures. Results: Modafinil did not affect clinical scales except PSQI which had been reduced after medication. In this study, Modafinil reduced total sleep time, sleep efficiency and increased wake after sleep onset and percent of arousal during sleep in nocturnal polysomnography and prolonged mean sleep latency in multiple sleep latency tests in both group. Discussion: Modafinil has stimulant effect of central nervous system but its effect on night sleep is less than other psychostimulants such as methylphenidate. We ascertained that modafinil affected total sleep time, sleep efficiency and percent of wake during sleep but did not effect on sleep structure. Modafinil was effective in the management of day time sleepiness. Modafinil can enhance alertness of control group without day time sleepiness.

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From the Onset of Panic Symptoms to Getting to a Psychiatric Treatment : The Change by Improved Public Awareness of Panic Disorder in Korea (증상의 발현부터 치료의 시작까지 : 한국인의 공황장애 인식도 변화가 치료적 접근에 미친 영향)

  • Choi, Yong-Won;Seo, Ho-Jun;Han, Sang-Woo;Hong, Jin-Pyo;Lee, Kyoung-Uk;Kim, Se-Joo;Lim, Se-Won;Lee, Sang-Hyuk;Yang, Jong-Chul;Lee, Seung-Jae;Park, Seon-Cheol;Gim, Min-Sook;Chae, Jeong-Ho
    • Anxiety and mood
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    • v.15 no.2
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    • pp.61-67
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    • 2019
  • Objective : This study aimed to investigate the general process from the symptom onset to the psychiatric treatment in Korean panic patients and the effect of improved public awareness on it. Methods : This study has a retrospective design. The subjects were the new patients with panic disorder who visited the psychiatric outpatient clinic in twelve university-affiliated hospitals all across Korea. The medical chart was reviewed retrospectively and the data were collected including chief complaints of symptoms, recent stressors, the time to visit the psychiatric outpatient clinic, and visit of other departments and diagnostic approaches for their symptoms. Results : A total of 814 participants were included in the study. The most common department other than psychiatry the panic patients visited were cardiology (28.3%), general internal medicine (16.0%) and neurology (11.4%). The most frequently used diagnostic tests were a echocardiography (17.9%), 24-hour Holter monitoring (11.2%), and brain MRI (8.2%). Only 37.3% of participants visited psychiatric clinic directly. About 80% of participants visited psychiatric department within 1 year after their first panic symptoms and it took $13.8{\pm}13.7weeks$ on average. Comparing before and after 2012, the number of participants increased who visit directly the psychiatric clinic without visiting other departments (p=0.002) and without visiting emergency room (p<0.001). Conclusions : Our results suggest that a substantial number of patients visit departments other than psychiatry when they experience first panic symptoms. However, most patients begin psychiatric treatment within 1 year after their first symptoms and the number of patient are increasing who visit psychiatric department directly without visiting other departments.

Behavioral Mechanism of Hybrid Model of Soil-nailing and Compression Anchor (쏘일네일링과 앵커가 결합된 하이브리드 공법의 거동 메커니즘)

  • Seo, Hyung-Joon;Kim, Hyun-Rae;Jeong, Nam-Soo;Lee, In-Mo
    • Journal of the Korean Geotechnical Society
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    • v.26 no.7
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    • pp.117-133
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    • 2010
  • A hybrid system of soil-nailing and compression anchor is proposed in this paper; the system is composed of an anchor bar (installed at the tip) with two PC strands and a steel bar. After drilling a hole, installing proposed hybrid systems, and filling the hole with grouting material, prestress is applied to the anchor bar to restrict the deformation at the head and/or to prevent shallow slope failures. However, since the elongation rate of PC strand is much larger than that of steel bar, yield at the steel bar will occur much earlier than at the PC strand. It means that the yield load of the hybrid system will be overestimated if we simply add yield loads of the two - anchor bar and PC strands. It might be needed to try to match the yielding time of the two materials by applying the prestress to the anchor bar. It means that the main purpose of applying prestress to the anchor bar should be two-fold: to restrict the deformation at the nail head; and more importantly, to maximize the design load of the hybrid system by utilizing load transfer mechanism that transfers the prestress applied at the tip to the head through anchor bar. In order to study the load transfer mechanism in a systematic way, in-situ pullout tests were performed with the following conditions: soil-nailing only; hybrid system with the variation of prestress stresses from 0 kN to 196 kN. It was found that the prestress applied to the anchor system will induce the compressive stress to the steel bar; it will result in decrease in the slope of load-displacement curve of the steel bar. Then, the elongation at which the steel bar will reach yield stress might become similar to that of PC strands. By taking advantage of prestress to match elongations at yield, the pullout design load of the hybrid system can be increased up to twice that of the soil-nailing system.

An event-related potential study of global-local visual perception in female college students with binge drinking (폭음 여자대학생의 전체-세부 시지각 처리에 관한 사건관련전위 연구)

  • So-yeon Lim;Myung-Sun Kim
    • Korean Journal of Cognitive Science
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    • v.34 no.2
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    • pp.111-151
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    • 2023
  • It is reported that binge drinkers show cognitive impairment similar to alcohol use disorder patients. A previous studies using neuropsychological tests and brain imaging techniques to investigate the visual perception of alcohol use disorder patients reported that they had global-local visual perception defects. Although the neurological basis for the global-local visual perception deficit in the heavy drinking group has been presented, there are no studies to date that have investigated the global-local visual perception in the heavy drinking group. This study investigated local-biased visual perception in female college students with binge drinking (BD) using event-related potentials (ERPs). Based on the scores of the Korean version of Alcohol Use Disorder Identification Test and the Alcohol Use Questionnaire, participants were assigned into BD (n=25) and non-BD (n=25) groups. Local-global visual processing was assessed using a local-global paradigm, in which large stimuli (global level) composed of small stimuli (local level) were presented. The stimuli presented at global and local levels were either congruent or incongruent. The behavioral results exhibited that the BD and non-BD groups did not differ in terms of accuracy and response time. In terms of ERPs, the BD and non-BD groups did not show difference in N100, P150 and N200 amplitude. However, the BD group showed significantly smaller P300 amplitude than non-BD group especially in the local condition. In addition, a negative correlation between P300 amplitude and binge drinking score was observed, i.e., severer binge drinking smaller P300 amplitude. The P300 is known to reflect cognitive inhibition and attentional allocation. In the global-local paradigm, the local condition required to attend to local target while ignoring global non-target. Therefore, the present results indicate that female college students with BD do not have local-biased visual processing, instead they seem to have difficulties in inhibition of irrelevant stimuli.

Surrogate Internet Shopping Malls: The Effects of Consumers' Perceived Risk and Product Evaluations on Country-of-Buying-Origin Image (망상대구점(网上代购店): 소비자감지풍험화산품평개대원산국형상적영향(消费者感知风险和产品评价对原产国形象的影响))

  • Lee, Hyun-Joung;Shin, So-Hyoun;Kim, Sang-Uk
    • Journal of Global Scholars of Marketing Science
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    • v.20 no.2
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    • pp.208-218
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    • 2010
  • Internet has grown fast and become one of the most important retail channels now. Various types of Internet retailers, hereafter etailers, have been introduced so far and as one type of Internet shopping mall, 'surrogate Internet shopping mall' has been prosperous and attracting consumers in the domestic market. Surrogate Internet shopping mall is a unique type of etailer that globally purchases well-known brand goods that are not imported in the market, completes delivery in the favor of individual buyers, and collects fees for these specific services. The consumers, who are usually interested in purchasing high-end and unique but not eligible brands, have difficulties to purchase these items overseas directly from the retailers or brands in other countries due to worries of payment failure and no address available for their usually domestic only delivery. In Korea, both numbers of surrogate Internet shopping malls and the magnitude of sales have been growing rapidly up to more than 430 active malls and 500 billion Korean won in 2008 since the population of consumers who want this agent shopping service is also expending. This etail business concept is originated from 'surrogate-mediated purchase' and this type of shopping agent has existed in many different forms and also in wide ranges of context level for quite a long time. As marketers face their individual buyers' representatives instead of a direct contact with them in many occasions, the impact of surrogate shoppers on consumer's decision making has been enormously important and many scholars have explored various range of agent's impact on consumer's purchase decisions in marketing and psychology field. However, not much rigorous research in the Internet commerce has been conveyed yet. Moreover, since as one of the shopping agent surrogate Internet shopping malls specifically connect overseas brands or retailers to domestic consumers, one specific character of the mall's, image of surrogate buying country, where surrogate purchases are conducted in, may play an important role to form consumers' attitude and purchase intention toward products. Furthermore it also possibly affects various dimensions of perceived risk in consumer's information processing. However, though tremendous researches have been carried exploring the effects of diverse dimensions of country of origin, related studies in Internet context has been rarely executed. There have been some studies that prove the positive impact of country of origin on consumer's evaluations as one of information clues in product manufacture descriptions, yet studies detecting the relationship between country image of surrogate buying origin and product evaluations rarely undertaken regarding this specific mall type. Thus, the authors have found it well-worth investigating in this specific retail channel and explored systematic relationships among focal constructs and elaborated their different paths. The authors have proven that country image of surrogate buying origin in the mall, where surrogate malls purchase products in and brings them from for buyers, not only has a positive effect on consumers' product evaluations including attitude and purchase intention but also has a negative effect on all three dimensions of perceived risk: product-related risk, shipping-related risk, and post-purchase risk. Specifically among all the perceived risk, product-related risk which is arisen from high uncertainty of product performance is most affected (${\beta}$= -.30) by negative country image of surrogate buying origin, and also shipping-related risk (${\beta}$= -.18) and post-purchase risk (${\beta}$= -.15) get influenced in order. Its direct effects on product attitude (${\beta}$= .10) and purchase intention (${\beta}$= .14) are also secured. Each of perceived risk dimension is proven to have a negative effect on purchase intention through product attitude as a mediator (${\beta}$= -.57: product-related risk ${\rightarrow}$ product attitude; ${\beta}$= -.24: shipping-related risk ${\rightarrow}$ product attitude; ${\beta}$= -.44: post-purchase risk ${\rightarrow}$ product attitude) as well. From the additional analysis, the paths of consumers' information processing are shown to be different based on their levels of product knowledge. While novice consumers with low level of knowledge consider only perceived risk important, expert consumers with high level of knowledge take both the country image, where surrogate services are conducted in, and perceived risk seriously to build their attitudes and formulate decisions toward products more delicately and systematically, which is in line with previous studies. This study suggests several pieces of academic and practical advice. Precisely, country image of surrogate buying origin does affect on consumer's risk perceptions and behavioral consequences. Therefore a careful selection of surrogate buying origin is recommended. Furthermore, reducing consumers' risk level is required to blossom this new type of retail business whether its consumer are novices or experts. Additionally, since consumer take different paths of elaborating information based on their knowledge levels, sophisticated marketing approaches to each group of consumers are required. For novice buyers strong devices for risk mitigation are needed to induce them to form better attitudes and for experts selections of better and advanced countries as surrogate buying origins are advised while endorsement strategy for the site might work as a reliable information clue to all consumers to mitigate the barriers to purchase goods online. The authors have also explained that the study suffers from some limitations, including generalizability. In future studies, tests of and comparisons among different types of etailers with relevant constructs are recommended to broaden the findings.