• Journal of the Korean Institute of Gas
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• v.27 no.3
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• pp.52-58
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• 2023

With the increasing awareness of the importance of carbon neutrality in response to global climate change, the utilization of hydrogen as a carbon-free fuel source is also growing. Hydrogen is commonly used in fuel cells (FC), but it can also be utilized in internal combustion engines (ICE) that are based on combustion. Particularly, ICEs that already have established infrastructure for production and supply can greatly contribute to the expansion of hydrogen energy utilization when it becomes difficult to rely solely on fuel cells or expand their infrastructure. However, a disadvantage of utilizing hydrogen through combustion is the potential generation of nitrogen oxides (NOx), which are harmful emissions formed when nitrogen in the air reacts with oxygen at high temperatures. In particular, for the EURO-7 exhaust regulation, which includes cold start operation, efforts to reduce exhaust emissions during the warm-up process are required. Therefore, in this study, the characteristics of nitrogen oxides and fuel consumption were investigated during the warm-up process of cooling water from room temperature to 88℃ using a 2-liter direct injection spark ignition (SI) engine fueled with hydrogen. One advantage of hydrogen, compared to conventional fuels like gasoline, natural gas, and liquefied petroleum gas (LPG), is its wide flammable range, which allows for sparser control of the excessive air ratio. In this study, the excessive air ratio was varied as 1.6/1.8/2.0 during the warm-up process, and the results were analyzed. The experimental results show that as the excessive air ratio becomes sparser during warm-up, the emission of nitrogen oxides per unit time decreases, and the thermal efficiency relatively increases. However, as the time required to reach the final temperature becomes longer, the cumulative emissions and fuel consumption may worsen.

• Annals of Clinical Neurophysiology
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• v.12 no.1
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• pp.21-26
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• 2010

Background: Although quantitative sensory test (QST) is being used with increasing frequency for measuring sensory thresholds in clinical practice and epidemiologic studies, there has been no age-matched normative data in Korean adults. The objective of this study is to evaluate the value of QST in diabetic polyneuropathy with normal range in Korean adults. Methods: The Computer Aided Sensory Examination IV 4,2 (WR Medical Electronics Co., Stillwater, Minnesota, U.S.A.), with 4,2,1 stepping algorithm was used to determine vibration and cold perception threshold in 70 normal controls and 19 patients with diabetic polyneuropathy aged from 21 to 79 years. The data were used to define age-matched upper and lower normal limits and normal range of side to side difference. We also evaluated the duration of diabetes, serum HbA1C level, and findings of nerve conduction study (NCS) and QST in patients with diabetic polyneuropathy. Results: In normal adults, sensory thresholds slightly increased with age, and a slight side-to-side difference was observed. The diagnostic sensitivity of QST was not higher than NCS in patients with diabetic polyneuropathy (36.8% vs. 42.1%, p=0.716), especially among elderly patients. Conclusions: QST might be used as a complementary test for NCS in the diagnosis of diabetic polyneuropathy. Although the QST is a simple method for the evaluation of peripheral nerve function, there are some limitations. Most of all, because the QST measuring is dependent on the subjective response of patients, the degree of concentration and cooperation of the patients can significantly affect the result. And thus, attention should be paid during the interpretation of QST results in patients with peripheral neuropathy.

• Journal of Life Science
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• v.28 no.3
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• pp.376-387
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• 2018

Among a variety of environmental stresses heat, cold, chilling, high salt, drought, and so on exposed to plants, drought stress has been reported as a crucial factor to adversely affect the growth and productivity of plants. Therefore, to understand the mechanism for the drought stress signal transduction pathway in plants is more helpful to develop useful crops that display the enhanced tolerance against drought stress, and to expand crop growing areas. The signal transduction pathway for the drought stress in plants is largely categorized into two types; ABA-dependent pathway and ABA-independent pathway. It has been reported that two transcription factors, AREB/ABF and DREB2, play predominant roles in ABA-dependent and ABA-independent pathways, respectively. In addition to transcriptional regulation mediated by AREB/ABF and DREB2 transcription factors, post-translational modification (such as phosphorylation and ubiquitination) and epigenetic control are importantly involved in the signal transduction for drought stress. In this paper, we review current understanding of signal transduction pathway on drought stress in plants, especially focusing on the biological roles of a variety of signaling components related to drought stress response. Further understanding the mechanism of drought resistance in plants through this review will be useful to establish theoretical basis for developing drought tolerant crops in the future.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.1
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• pp.11-27
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• 2017

The road network system of major domestic urban areas such as city of Seoul was rapidly developed and regionally expanded. In addition, many kinds of life-lines such as electrical cables, telephone cables, water&sewerage lines, heat&cold conduits and gas lines were needed in order for urban residents to live comfortably. Therefore, most of the life-lines were individually buried in underground and individually managed. The utility tunnel is defined as the urban planning facilities for commonly installing life-lines in the National Land Planning Act. Expectation effectiveness of urban utility tunnels is reducing repeated excavation of roads, improvement of urban landscape; road pavement durability; driving performance and traffic flow. It can also be expected that ensuring disaster safety for earthquakes and sinkholes, smart-grind and electric vehicle supply, rapid response to changes in future living environment and etc. Therefore, necessity of urban utility tunnels has recently increased. However, all of the constructed utility tunnels are cut-and-cover tunnels domestically, which is included in development of new-town areas. Since urban areas can not accommodate all buried life-lines, it is necessary to study the feasibility assessment system for utility tunnel by urban patterns and capacity optimization for urban utility tunnels. In this study, we break away from the new-town utility tunnels and suggest a quantitative assessment model based on the evaluation index for urban areas. In addition, we also develop a program that can implement a quantitative evaluation system by subdividing the feasibility assessment system of urban patterns. Ultimately, this study can contribute to be activated the urban utility tunnel.

• Journal of dental hygiene science
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• v.7 no.4
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• pp.281-286
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• 2007

The purpose of this research was to find out their perception of the dental hygiene and level of its knowledge by estimating status of senior adults' dental health management. First, questionnaires were distributed to the 256 target senior adults aged more than 60, who were going to school for senior adults located in Ulju Country and the survey was conducted by interview directly. The results were as follows; 1. As for tooth brushing method, scrubbing method was used in male and rolling method was used in female and the survey results statistically revealed that rolling method was the most used in aged from 60 to 70(68.1%) and scrubbing method was the most used in aged more than 70(80.4%)[p < 0.001]. 2. As for reason of visiting dental clinic, female respondents accounting for the highest said they visited dental clinic when they feel a pain in the teeth and as for frequence of dental clinic, male respondents visited dental clinic for a once per a year. there was no difference statistically according to age(47.9%). 3. As for the perception of the necessity of dental prosthetic treatment, there was higher positive response in the female than male, in the lower aged groups than higher aged group[p<0.05]. 4. As for the question of whether to use of denture or not now, the survey results was statistically that the higher aged group and male groups were higher used dentures [p < 0.001]. 5. As for maintenance of denture, female respondents said the highest that they keep it in cold water after cleaning(95.5%), there was no difference statistically according to age and educational background [p < 0.001].

• Proceedings of KOSOMES biannual meeting
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• 2018.06a
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• pp.16-16
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• 2018

2017년 겨울, 기록적인 한파로 인해 바다가 얼면서 인천 앞바다로 유빙이 유입되었다. 2013년 해상에서 유빙이 발견된 이후 약 5년만에 다시 유빙이 등장한 것이다. 중부청 소속 항공단 순찰결과에 따르면, 2018년 1월 12일 인천대교 인근 해상에서 최초로 발견된 이후 강화 연안, 영종도 북단 등 해상에서 광범위하고 불규칙한 형태로 유빙이 분포되어 있는 것으로 나타났다. 유빙의 문제점은 해상에서 선박의 안전운항을 저해하고 경비함정의 안전에 지장을 초래하며 기름 유출 시, 유출유의 거동 특성이 달라져 일반적인 방제방법의 적용이 곤란한 점이다. 이에 따라 해상에서의 해양오염사고 대응방안 마련을 위해 저온 및 유빙 유입 해상에서 유출유의 거동 특성을 알아보았다. 구분인자를 극한의 추위(Extreme Cold), 유빙(Pack Ice), 정착빙(Fast Ice) 3가지로 분류하여 기름의 성상변화 및 시사점을 살펴보고, 유출된 기름의 효율적 방제를 크게 3가지로 분류(기계적 봉쇄 및 회수, 화학적 분산제의 사용, 현장소각)하였다. 일반적인 방제장비를 저온 및 얼음분포 해상에서 사용 시 슬러시화 된 얼음으로 인해 유출유 회수가 어렵고, 동결온도에서 장비가 오작동할 우려가 있다. 이미 북유럽 국가에서는 극한의 추위와 얼음분포 해상에 특화된 방제장비를 도입하여 해양오염대비 대응을 하고 있다. 2003년 3월 발틱해에서 불법적으로 유출한 선저폐수를 특화 장비는 brush bucket 유회수기 이용 방제조치한 사례가 있으며, 2006년 5월 같은 장소에서 선박 침몰로 인한 기름 유출이 발생했을때도 brush bucket 유회수기 이용 방제조치를 하였다. 국내에도 이상 기후로 인해 기록적인 한파가 지속되면서 북극에서나 볼 법한 유빙들이 발견되고, 해양오염사고는 언제 어디서나 발생할 수 있으므로, 해양오염방제의 임무를 맡고 있는 국가기관으로써 특수한 환경까지도 고려하여 대응방안을 마련할 필요가 있다. 해양오염이 재난으로 인식되고 있는 상황에서, 그리고 지구온난화로 인한 이상기후변화가 지속되는 상황에서 겨울철 유빙 유입은 점점 더 많아질 수 있다. 본 연구에서는 자료나 방제경험이 부족하므로 일찌감치 북극항로 개발로 앞선 방제기술과 경험을 가지고 있는 북극이사회를 벤치마킹하여 관할 해역 특성에 맞는 대응방안을 고찰해 본다.

• Journal of Society of Preventive Korean Medicine
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• v.19 no.3
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• pp.29-43
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• 2015

Objective : The purpose of this study was to identify characteristics of patients' self-perceived health in traditional Korean medical facilities. Method : This research was conducted based on the survey on patients whom have visited traditional Korean medical facilities in 2011 by the Ministry of Health and Welfares and Korean Institute for Health and Social Affairs. Using a sample of 3,931 (1,180 male and 2,751 female) outpatients' self-perceived health based on the data from usage and consumption of Korean Medicine. 'Healthy', 'Fair', and 'Poor Health' were used to measure patients' self-perceived health status. The data was analyzed by frequency, t-test, cross correlation analysis and multiple logistics regression analysis using the SPSS program package. Results : Sex(P<0.001), age(P<0.001), marital status(P<0.001), education(P<0.001), employment status(P<0.001), occupation(P<0.001), health insurance(P<0.001) and income level(P<0.0001) showed statistical significance. Main Treatment Facilities(P<0.001), experience of taking Korean medicine(P=0.032), experience of receiving acupuncture treatment(P<0.001), number of visits(P<0.001), medical expense (P=0.005), and subjective health status after the treatments showed statistical significance for Korean herbal medicine(P=0.038), acupuncture (P=0.001), cupping therapy(P=0.006), oriental physiotherapy(P=0.003), and treatment satisfaction(P<0.001). For subjective health status based on suffering disorders in the past three months, the response of poor health was higher in the group suffering recent illnesses. Statistical significance was seen in hypertension (P=0.002), arthritis(P<0.001), lumbar pain(P<0.001), diabetes mellitus(P=0.001), stroke(P<0.001), hwa-byung (P=0.001), gastric disorders(P=0.021), common cold(P<0.001), ankle sprain(P<0.001), muscular injury(P<0.001), lumbar sprain(p=0.009) and fracture(P=0.03). Also the number of diseases during the past three months showed statistical significance(P<0.001). Statistical significance was also seen in Level of knowledge(P<0.001), route of information(P<0.001), reliability of Korean medicine(P=0.003), insurance coverage(P=0.005), medical costs(P<0.001), and future willingness to use Korean medicine(P<0.001). As a result of the multiple logistics regression analysis, risks of subjective poor health statistically increased in female population, elderlies, medicaid beneficiaries, less educated, higher medical expense, and more disorders during the past three months. Conclusion : Patients' self-perceived health status has significant differences with each variables such as sex, age, marital status, education, health insurance, medical expense, number of diseases.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.18 no.2
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• pp.36-50
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• 2005

Background and Objectives: Allergic rhinitis is an allergic reaction characterized by sneezingm itchy nose, mouth and throat, congestion and/or nasal discharge. The offending allergenes are usually pollens, molds, dust mites and animal allergen. Recently, the incidence of infectious nasal diseases tend to decrease. However, allergic rhinitis has increased and treatment in most cases has only deat with the symptom. Tongkyu-tang was composed of sixteen crude drugs. The Oriental Medical References mention therapeutic effects of Tongkyu-tang on nasal obstruction, watery nasal discharg. And Tongkyu-tang has clinically been used for the treatment of common cold, headache, sternutation, rhinitis etc. Speacially Tongkyu-tang is one of the most frequently used medical treatment for the allergic rhinitis. Experimental studies were conducted to investigate for the effect of Tongkyu-tang on the changes of neutrophil segment, lymphocyte, total IgE and nassal tissue in allergic rhinitis of ovalbumin-inhalation rat. Meterial and Methods: Fifteen Sprague-Dawley rats were divided into three group: normal group, control group, experimental group. To induce the allergic rhinitis in control group and experimental group, rats were sentitized intraperitoneally with 0.1 % ovalbumin solution 3 times at intervals of I week. Then intranasal sensitization was performed by diffusing 0.1 % ovalbumin solution 3 times at intervals of 2 days. After that time, rat in the experimental group were oral administration treated by Tongkyu-tang for 28 days. We observed changes in nasal tissue; changes in the number of white blood cell, red blood cell and total Ig E; also changes in the segment of neutrophil and lymphocyte in blood. And we observed the changes of AST, ALT of three group. We used anova test statistically. Result: The number of leucocyte remained unchanged between three group. The number of erythrocyte was increased in experimental group and control group when compared with the normal group. The segment of neutrophil, in blood was decreased in experimental group when compared with the control group but, that was not significant statistically(p<0.05). The promotion of lymphocyte in blood was significantly decreased in experimental group when compared with the Control group(p<0.05). Total IgE was decreased in experimental group when compared with the control group but, that was not significant statistically(p<0.05). The cilium be well preserved in experimental group: the nasal tissue in experimental group was similar to in the normal group. Congestion and expantion of grandular cell in nasal submucosa, hypertropy of epithelium in nasal mucosa, acid mucus in epithelium and neutral mucus in subepithelium were decreased in experimental group when compared with the control group. Effect of Tongkyu-tang on the liver function were also studies in rats. Treatment of Tongkyu-lang did not affected on AST and ALT. Conclusion: Considering the above experimental results, it is suggested that oral administration treatment using Tongkyu-lang, without worry about liver function injury, decreased response on an Animal model with Allergic Rhinitis.

• Journal of Animal Science and Technology
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• v.62 no.4
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• pp.504-520
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• 2020

Proliferation of shrubs at the expense of native forage in pastures has been associated with large changes in dry-matter intake and dietary components for grazing ruminants. These changes can also affect the animals' physiology and metabolism. However, little information is available concerning the effect of pastoral-shrub grazing on the rumen bacterial community. To explore rumen bacteria composition in grazing yaks and the response of rumen bacteria to increasing shrub coverage in alpine meadows, 48 yak steers were randomly assigned to four pastures with shrub coverage of 0%, 5.4%, 11.3%, and 20.1% (referred as control, low, middle, and high, respectively), and ruminal fluid was collected from four yaks from each pasture group after 85 days. Rumen fermentation products were measured and microbiota composition determined using Ion S5™ XL sequencing of the 16S rRNA gene. Principal coordinates analysis (PCoA) and similarity analysis indicated that the degree of shrub coverage correlated with altered rumen bacterial composition of yaks grazing in alpine shrub meadows. At the phyla level, the relative abundance of Firmicutes in rumen increased with increasing shrub coverage, whereas the proportions of Bacteroidetes, Cyanobacteria and Verrucomicrobia decreased. Yaks grazing in the high shrub-coverage pasture had decreased species of the genus Prevotellaceae UCG-001, Lachnospiraceae XPB1014 group, Lachnospiraceae AC2044 group, Lachnospiraceae FCS020 group and Fretibacterium, but increased species of Christensenellaceae R-7 group, Ruminococcaceae NK4A214 group, Ruminococcus 1, Ruminococcaceae UCG-002, Ruminococcaceae UCG-005 and Lachnospiraceae UCG-008. These variations can enhance the animals' utilization efficiencies of cellulose and hemicellulose from native forage. Meanwhile, yaks grazed in the high shrub-coverage pasture had increased concentrations of ammonia nitrogen (NH₃-N) and branched-chain volatile fatty acids (isobutyrate and isovalerate) in rumen compared with yaks grazing in the pasture without shrubs. These results indicate that yaks grazing in a high shrub-coverage pasture may have improved dietary energy utilization and enhanced resistance to cold stress during the winter. Our findings provide evidence for the influence of shrub coverage on the rumen bacterial community of yaks grazing in alpine meadows as well as insights into the sustainable production of grazing yaks on lands with increasing shrub coverage on the Qinghai-Tibet Plateau.

• The Korea Journal of Herbology
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• v.25 no.4
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• pp.11-16
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• 2010

Objective : Oriental medicines have been combined oriental medical theory which based on the seven modes of emotions. Notopterygium incisum (N. incisum) and Clematis manshurica (C. manshurica) have been used as an anti-rheumatic and analgesic medicine for the treatment of rheumatism, headache, cold, etc. In this study, we evaluate the synergistic anti-inflammatory effect of N. incisum and C. manshurica. Method : To evaluate the synergistic anti-inflammatory effect of a herbal mixture N. incisum and C. manshurica, we examined the changed ear thickness in 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-induced mouse ear edema model after topical application of herbal mixture. In addition, the levels of markers for inflammation, such as tumor necrosis factor (TNF)-${\alpha}$, interleukin (IL)-$1{\beta}$, prostaglandin $G_2$ ($PGE_2$), and nitric oxide (NO) were measured by ELISA assay and Griess reagent in lipopolysaccharide-stimulated Raw 264.7 cells. Results : Our results showed that aqueous extracts of N. incisum and C. manshurica combination significantly inhibited the mouse ear edema induced by TPA. Moreover, the aqueous extracts of N. incisum and C. manshurica combination exhibited synergistic effects in down-regulating TNF-${\alpha}$, IL-$1{\beta}$, $PGE_2$ level, but not NO. Conclusions : This study suggested that combined treatment of N. incisum and C. manshurica, based on seven methods in prescription compatibility, has a synergistic effect in down-regulating inflammatory response both in vitro and in vivo models.