• Title/Summary/Keyword: Fatigue strong

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Bonding Property and Reliability for Press-fit Interconnection (Press-fit 단자 접합특성 및 신뢰성)

  • Oh, Sangjoo;Kim, Dajung;Hong, Won Sik;Oh, Chulmin
    • Journal of the Microelectronics and Packaging Society
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    • v.26 no.3
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    • pp.63-69
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    • 2019
  • Soldering technology has been used in electronic industry for a long time. However, due to solder fatigue characteristics, automotive electronics are searching the semi-permanent interconnection technology such as press-fit method. Press fit interconnection is a joining technology that mechanically inserts a press fit metal terminal into a through hole in a board, and induces a strong bonding by closely contacting the inner surface joining of the through hole by plastic deformation of press-fit terminal. In this paper, the bonding properties of press-fit interconnection are investigated with PCB hole size and surface finishes. In order to compare interconnection reliability between the press fit and soldering, the change in resistance of the press-fit and soldering joints was observed during thermal shock test. After thermal cycling, the failure modes are investigated to reveal the degradation mechanism both press-fit and soldering technology.

Healing Function Evaluation of Color Samples from the Healthcare Environmental Color Index - A Cross-cultural Comparison Study on Korean and Romanian users

  • Ardelean, Ioana;Oh, Jiyoung;Park, Heykyung
    • International Journal of Advanced Culture Technology
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    • v.9 no.3
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    • pp.131-141
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    • 2021
  • The present study is following a series of research investigations on design resources coming from collected data referring to users' awareness and preferences. The aim of this research is to test the Healthcare Environmental Color Index as a basis for practitioners in the field of healthcare design. An array of color samples selected from previous research, have been presented to the respondents via an online survey, in order to identify the preferences of the two groups on the relation between environmental color and health. As a result of the first experiment and through the comparison of processed data, the maximum percentage of respondents from each group is validating the relation between environmental color and health. For the second experiment we intend to highlight the patterns of color preferences for each group, and thus to test the color samples healing function. The compared data also showed a higher awareness of Koreans than Romanians on the potential of color applied to healing environment. Last but not least in the third experiment we show the top five color samples preferred by each group. It is significant that the comparison of the results validated once more some of our previous findings related to the healthcare environment, such as: the general preference for the green hue (associated to fatigue relax according to color psychology) and the blue hue (sedation release effect) but also the yellow hue - associated to bright energy. Three out of the top five preferred color samples have been identical to both groups while the other two samples have shown characteristic variations. These results show that similarities are strong and can be used in a glocal design strategy as an accessible tool for any practitioner. Based on the Healthcare Environmental Color Index and users' preferences analysis, a new design culture for healthcare can be established and developed.

Long-term administration of red ginseng non-saponin fraction rescues the loss of skeletal muscle mass and strength associated with aging in mice

  • Cho, Da-Eun;Choi, Gwang-Muk;Lee, Yong-Seok;Hong, Joon-Pyo;Yeom, Mijung;Lee, Bombi;Hahm, Dae-Hyun
    • Journal of Ginseng Research
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    • v.46 no.5
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    • pp.657-665
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    • 2022
  • Background: Sarcopenia is a new and emerging risk factor aggravating the quality of life of elderly population. Because Korean Red Ginseng (RG) is known to have a great effect on relieving fatigue and enhancing physical performance, it is invaluable to examine its potential as an anti-sarcopenic drug. Methods: Anti-sarcopenic effect of non-saponin fraction of Korean Red Ginseng (RGNS) was evaluated in C2C12 myoblasts treated with C2-ceramide to induce senescence phenotypes, and 22-month-old mice fed with chow diet containing 2% RGNS (w/w) for 4 further months. Results: The RGNS treatment significantly alleviated cellular senescence indicated by intracellular lipid accumulation, increased amount of lysosomal β-galactosidase, and reduced proliferative capacity in C2C12 myoblasts. This effect was not observed with saponin fraction. In an aged mouse, the 4-month-RGNS diet significantly improved aging-associated loss of muscle mass and strength, assessed by the weights of hindlimb skeletal muscles such as tibialis anterior (TA), extensor digitorum longus (EDL), gastrocnemius (GN) and soleus (SOL), and the cross-sectional area (CSA) of SOL muscle, and the behaviors in grip strength and hanging wire tests, respectively. During the same period, an aging-associated shift of fast-to slow-twitch muscle in SOL muscle was also retarded by the RGNS treatment. Conclusions: These findings suggested that the long-term diet of RGNS significantly prevented aging-associated muscle atrophy and reduced physical performance, and thus RGNS has a strong potential to be developed as a drug that prevents or improves sarcopenia.

Study of Situation Prediction Simulation for Navigation Information System of Ship (선박의 항행정보시스템을 위한 상황 예측 시뮬레이션 방안 연구)

  • Yi, Mi-Ra
    • Journal of the Korea Society for Simulation
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    • v.19 no.3
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    • pp.127-135
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    • 2010
  • Modern marine navigation requires officers on the bridge to monitor a torrent of data on both the insides and outsides of the ship from numerous useful devices. But despite these tools, navigators can still find it difficult to make a safe decision for two reasons: one is that too much data if provided too quickly tends to cause fatigue and overwhelm the officer, and the other is that any inconsistency across data from several different types of devices can lead to confusion. Indeed, the fact remains that the many marine accidents can be attributed to human error, and hence there is a strong need for decision-support tools for marine navigation. One technique of providing decision support is through the use of simulation to evaluate or predict system dynamics over time using an accurate model. This paper, as a simulation method for risk prediction for a navigation safety information system of ship, suggests a navigation prediction simulation system using various knowledge bases and discrete event simulation methodology, and supports the validity of the system through the examples of components in a restricted navigation situation scenario.

A Study on Anxiety-Depression in College Freshmen (신불안.우울척도에 의한 대학신입생의 정신건강평가서)

  • Lee, Jong-Bum;Kim, Chang-Su;Park, Hyeung-Bae;Park, Byung-Tak;Lee, Jung-Hoon;Cheung, Seung-Douk
    • Journal of Yeungnam Medical Science
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    • v.4 no.2
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    • pp.29-38
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    • 1987
  • The authors studied anxiety-depression using New Anxiety-Depression Scale (NADS) in the subjects of 2.564 male and 1,252 female college freshmen of Yeungnam University. The authors collected the reports of NADS during the periods from January to February 1987, and applied NAOVA and t-test on anxiety depression scores in order to compare them between various psychosocial factors and sexes. The results are as follows : There was significant difference in the mean average of total scores between male and female students : male students scored $33.41{\pm}8.76$ and female students scored $35.34{\pm}9.02$ (P<0.001). The anxiety-depression scores relating to the items of sleep disturbance, apprehension, facial flushing and fatigue were relatively scored higher in both groups. One hundred and thirty nine male students (5.4%) showed seriously higher degree of anxiety-depression scores of 50 or more, while eighty eight female students (7.0%) showed the sane scores. There was a strong tendency toward higher anxiety-depression scores in the students who were dissatisfied with their home atmosphere, colleges, departments, familiarity of parents am those who had pessimistic views of self image in the past, presents and future in both groups (P<0.001).

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A Case Study for the Estimation of Remaining Lives of Asphalt Pavements (아스팔트포장 잔존수명 예측 사례 연구)

  • Lee, Jung-Hun;Lee, Hyun-Jong;Park, Hee-Mun;Kim, In-Tai
    • International Journal of Highway Engineering
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    • v.10 no.2
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    • pp.1-13
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    • 2008
  • This study presents a case study of condition evaluation of various asphalt pavement sections to estimate performance lives. The pavement surface conditions including cracking and rutting are first evaluated using a automatic pavement analyzer, ARAN. HPCI(Highway Pavement Condition Index) values are estimated using the pavement surface distress data. It is observed from the pavement distress survey that the major distress type of the sections is top-down cracking. The modulus value of each pavement layer is back-calculated from the defection data obtained from a FWD(Falling Weight Deflectometer) and compared with the laboratory measured dynamic modulus values. Remaining lives of the various pavement sections are estimated based on a mechanistic-empirical approach and AAHTO 1993 design guide. The structural capacities of the all pavement sections based on the two approaches are strong enough to maintain the pavement sections for the rest of design life. Since the major distress type is top-down cracking, the remaining lives of the pavement sections are estimated based on HPCI and existing performance database of highway pavements. To evaluate the causes of premature pavement distress, various material properties, such as air void, asphalt binder content, aggregate gradation, dynamic modulus and fatigue resistance, are measured from the field cores. It is impossible to accurately estimate the binder contents of field samples using the ignition method. It is concluded from the laboratory tests that the premature top down cracking is mainly due to insufficient compaction and inadequate aggregate gradation.

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A Study on Anxiety-Depression in College Freshmen (신불안.우울척도에 의한 대학 신입생의 정신건강 평가)

  • Park, Hyeong-Bae;Kim, Jin-Sung;Kim, Chang-Su;Park, Byung-Tak;Lee, Jong-Bum;Lee, Jung-Hoon;Cheung, Seung-Douk
    • Journal of Yeungnam Medical Science
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    • v.4 no.1
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    • pp.105-121
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    • 1987
  • The authors studied anxiety-depression using New Anxiety-Depression Scale(NADS), in the subjects of 3,499male and 1,335 female college freshmen of Yeungnam University. The authors collected the reports of NADS during the periods from January to February, 1986, and applied ANOVA and t-test on anxiety-depression scores in order to compare them between various psychosocial factors, and sexs. The results are as follows : There was significant difference in the mean awerages of total scores between male and female students: male students scored $31.49{\pm}6.57$ female students scored $33.37{\pm}6.84$ (P<0.001) The anxiety-depression scores relating to the items of sleep disturbance, apprehension, decreased libido and fatigue were relatively higher in both groups. Ninety-nine male students(2.8%) showed seriously high degree anxiety-depression scores of 50 or higher, while forty female students(3.0%) showed the same scores. There was a strong tendency toward higher anxiety-depression scores in the students who were dissatisfied with their home atmosphere, colleges, departments and familiarity of parents, and those who had pessimistic views of self image in the past, present, or fartare in both groups (P<0.001) The students whose maturation locations were below city level, showed higher level of anxiety-depression scores in both groups (P<0.05) NADS and SAS, SDS, and Leeds scale were correlated significantly in 0.64, 0.61, and 0.77 of correlation coefficient.

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Antioxidative and Antimutagenic Effects of the Ethanol Elrtract from Cordyceps militaris (번데기동충하초(Cordyceps militaris) 에탄을 추출물의 항산화성 및 항돌연변이원성 효과)

  • 김미남;오상화;이득식;함승시
    • Food Science and Preservation
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    • v.8 no.1
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    • pp.109-117
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    • 2001
  • Cordyceps militaris is a parasitic fungus that has been used as a Chinese medicine for the treatment of fatigue, debility, kidney disease, tuberculosis, asthma and cardiac insufficiency etc. This study was carried out to determine the antioxidative and antimutagenic effects of Cordyceps militaris using DPPH free radical donating method and Ames test, respectively. They were extracted with ethanol and then further fractionated to n-hexane, chloroform, ethyl acetate, butanol and water, stepwise. Among five fractions, the EtOAc and BuOH fractions showed the highest electron donating activities, about 2-fold higher than other fractions. In Ames test, most of the extracts had strong antimutagenic effects against the mutagenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine(MNNG), 4-nitroquinoline-1-oxide(4NQO), benzo($\alpha$)pyrene(B($\alpha$)P) and 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indol (Trp-P-1). The EtOH extracts of C. militaris (200 $\mu\textrm{g}$/plate) showed 62.8%, 74.4% and 67.2% inhibitory effects on the mutagenesis induced by 4NQO, B($\alpha$)P and Trp-P-1, respectively, against TA98 strain, whereas 78.1%, 78.6%, 78.6% and 82.7% inhibition were observed on the mutagenesis induced by MNNG, 4NQO, B($\alpha$)P and Trp-P-1, respectively, against TA100 strain. Especially, the BuOH fraction showed the highest antimutagenic effects against mutation induced by MNNG.

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Aerodynamic Characteristics and Galloping Possibility of Ice Accreted Transmission Conductors by Wind Tunnel Tests (풍동실험을 통한 착빙 가공송전선의 공력 특성 측정 및 갤러핑 발생 분석)

  • Lee, Dooyoung;Goo, Jaeryang;Park, Sooman;Kim, Donghwan
    • KEPCO Journal on Electric Power and Energy
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    • v.3 no.2
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    • pp.79-88
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    • 2017
  • In this paper, the wind tunnel test for the measurement of aerodynamic characteristics of transmission conductors with asymmetric sections is described. A single conductor model and bundled conductor models with ice accreted shapes are tested both in steady and turbulent flow, and the aerodynamic coefficients are acquired. Transmission conductor galloping is a kind of wind-induced vibration which is characterized by primarily vertical oscillation with a very low frequency and a high amplitude. It is well known that transmission conductor galloping is generally caused by moderately strong, steady winds when a transmission conductor has an asymmetric cross-section shaped by accreted ice. Galloping should be considered from the design stage of overhead lines because it can cause severe wear and fatigue damage to attachments as well as transmission conductors. It is reported that there have been normally 20 events of galloping per year in Korea, which may be followed by serious consequences in the electric power system. Therefore, this research is performed to measure aerodynamic characteristics of ice accreted transmission conductors to understand and control transmission conductor galloping so that it would help to prevent unexpected failures and reduce the maintenance costs caused by galloping.

'Study on Oui-Ga-Sil( 胃家實 )' (위가실(胃家實)에 관(關)한 연구(硏究))

  • Han, Gyu-Eon;Ryu, Bong-Ha;Park, Dong-Won;Ryu, Gi-Won;Jang, In-Gyu
    • The Journal of Internal Korean Medicine
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    • v.10 no.1
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    • pp.65-80
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    • 1989
  • About Oui-Ga-Sil(胃家實) in order to considerate the contents recorded in Nai-Gyung Sang-Han-Lon and latter literature, definition, etiopathology, syndrome, differential diagnosis, therapy, Prognosis and prevention were classified. And the results were as follows: 1. Oui-Ga(胃家)was a term which indicated the whole digestive system such as stomach, small intestine, large intestine, rectum and anus. Sil(實)could be defined as the peculiar concept pertaining to the acute and last stage which was invaded to inside bowels because of abundance with evil influence. 2. Eliology of Oui-Ga-Sil was abunt gastric fever originally, injured mucus because of mistreatment, the invasion to inside of outside evil influence through meridian. Pathology was the opening and shutting appearance of gastric abundance with intestinal emptiness, and intestinal abundance with gastric emptiness, Oui-Ga-Sil could be occurred because of gastric abundant dryness and splenic humidifying capacity decrease. 3. Symptom of Oui-Ga-Sil was classified as for the sunlight outside syndrome and the inside abundant syndrome. The sunlight outside syndrome was body fever, sweating, no chilling, on the contrary hatred of fever. The chief complaint of inside abundant syndrome was daily fever, talking in delirium, hand and foot sweating, abdominal distention, difficult defection and those could be pertained to sunlight bowel syndrome. 4. Diagnostic views of Oui-Ga-Sil were that pulse was descending abundant large strong and smooth quick, a coated tongue was yellow, deep yellow, old yellow, thick, scorching dry rough or gray black. On abdominal diagnosis, pressing by hand, patient was conscious of pain, excessive pain, rejection against press, impossible press or intermittent abdominal pain and bowel cutting pain without press. 5. Differential diagnosis was that the sunlight of Nai-Gyung-Fever-Theory was outside desease making meridian the prime object, Baik-Ho-Tang syndrome was making figureless abundant fever the pivotal point. And important differential standard of splenic shrink syndrome was that a daily fever, an irritation with fever were not occurred. 6. Theory of Oui-Ga-Sil was that Seng-Gi-Tang classes had been used in attacking downward or making balance, and moxibustion on Jung-Wan, honey boiling induction theory had been also used. Attacking downward therapy was invigorating method to preserve mucus, and if mucus had been exausted with complicating emptiness prognosis had been appeared badly. 7. Preventing from Oui-Ga-Sil diet by rule, fitness to cold and warmth may be needed to prevent outside evil influence attack and inside evil influence occurrence. Prudence with being very busy, fatigue, wine and woman may be also needed not to be an injury to splanic and gastric spirit.

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