• 한국수소및신에너지학회논문집
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• 제33권1호
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• pp.95-104
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• 2022

Micro hydropower is a readily available renewable energy source that can be harvested utilizing hydrokinetic turbines from shallow water canals, irrigation and industrial channel flows, and run-off river stream flows. These sources generally have low head (<1 m) and low velocity which makes it difficult to harvest energy using conventional turbines. A horizontal-axis screw turbine was designed and numerically tested to extract power from such low-head water sources. The 3-bladed screw-type turbine is placed horizontally perpendicular to the incoming flow, partially submerged in a narrow water channel at no-head condition. The turbine hydraulic performances were studied using Computational Fluid Dynamics models. Turbine design parameters such as the shroud diameter, the hub-to-shroud ratios, and the submerged depths were obtained through a steady-state parametric study. The resulting turbine configuration was then tested by solving the unsteady multiphase free-surface equations mimicking an actual open channel flow scenario. The turbine performance in the shallow channel were studied for various Tip Speed Ratios (TSR). The highest power coefficient was obtained at a TSR of 0.3. The turbine was then scaled-up to test its performance on a real site condition at a head of 0.3 m. The highest power coefficient obtained was 0.18. Several losses were observed in the 3-bladed turbine design and to minimize losses, the number of blades were increased to five. The power coefficient improved by 236% for a 5-bladed screw turbine. The fluid losses were minimized by increasing the blade surface area submerged in water. The turbine performance was increased by 74.4% after dipping the turbine to a bottom wall clearance of 30 cm from 60 cm. The final output of the novel horizontal-axis screw turbine showed a 2.83 kW power output at a power coefficient of 0.63. The turbine is expected to produce 18,744 kWh/year of electricity. The design feasibility test of the turbine showed promising results to harvest energy from small hydropower sources.

• Asian Pacific Journal of Cancer Prevention
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• 제17권10호
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• pp.4591-4597
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• 2016

Purpose: Decisions as to whether to provide adjuvant treatment in older breast cancer patients remains challenging. Side effects of chemotherapy have to be weighed against life expectancy, comorbidities, functional status, and frailty. To aid decision-making, we retrospectively analyzed 110 women with breast cancer treated with a curative intention from 2006 to 2012. Survival data with clinical and pathological parameters were evaluated to address the role of adjuvant chemotherapy in this study population. Method: A total of 110 elderly (>70 years) patients that received mastectomy at two hospitals in Taiwan were observed retrospectively for a medium of 51 months. After mastectomy, patients received conservative treatment or adjuvant chemotherapy, or hormone therapy following clinical guidelines or physician's preference. Data were collected from the cancer registry system. Results: Median age at diagnosis was 75.7 years. Thirty-five percent of patients received adjuvant chemotherapy, these having a significantly younger age ($mean=74.0{\pm}5.3$ vs $77.5{\pm}5.3$, p<0.001) and higher tumor staging (p=0.003) compared with their non-chemotherapy counterparts.Five-year overall survival was non-significantly higher in patients who received adjuvant chemotherapy (with chemotherapy 64.2% vs without chemotherapy 62.6%, p=0.635), while five-year recurrence free survival was non-significantly lower (with chemotherapy 64.1% vs without chemotherapy 90.5%, p=0.80). Conclusions: In this analysis, adjuvant chemotherapy tended to be given to patients with a younger age and higher tumor staging at our institute. It was not associated with any statistically significant improvement in survival and recurrence rate. Until age specific recommendations are available, physicians must use their clinical judgment and assess the tumor biology with the patient's comorbidities to make the best choice. Clinical trials focusing on this critical issue are warranted.

• 한국치위생학회지
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• 제4권2호
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• pp.135-151
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• 2004

The purpose of this study was to examine how much knowledge dental-hygiene students had about AIDS and how they looked at that. The subjects in this study were 370 freshmen, sophomores and juniors who were majoring in dental hygiene. The findings of this study were as follows : The rate of the students who were accurately aware of AIDS dissemination ranged from 59 to 92 percent. Those who knew that the disease didn't spread through routine daily contacts stood at 63 to 91 percent, and the students who were correctly cognizant of the cause of AIDS numbered 41 to 77 percent. Those who grasped the seriousness of that disease stood at 45 to 83 percent. The students weren't properly aware of how to prevent AIDS, as just 33 to 68 percent knew about that. Concerning connections between school year and AIDS knowledge, the sophomores had a better knowledge on its dissemination, cause and AIDS itself than the freshmen and juniors. As for attitude toward AIDS, 72.4 percent considered themselves not to be susceptible to that disease, but 361 percent felt that they were likely to develop it. 44.6 percent weren't afraid of being attacked by that disease, but more students feared about that possibility. Most of the students, who ranged from 77 to 88 percent, hoped to continue to be educated about that, and as many as 92 percent believed that AIDS patients should separatedly be treated. A lot of the students, which accounted for 90 percent, felt fear in the course of treatment, but 44 percent believed that AIDS patients should equally be treated, which indicated that they had a sense of responsibility. As to the relationship of school year to altitude toward AIDS, when their ideas about the danger of AIDS were asked, the freshmen and juniors considered themselves not to be susceptible to that disease more than the sophomores did, and the former group felt, more than the latter, that AIDS infection should be more thoroughly prevented than hepatitis in dental clinic. The juniors had a stronger tendency to find themselves to be exposed to AIDS as equally as most other people, compared to the freshmen and sophomores. The sophomores felt higher need for AIDS - related education, and had a stronger sense of duty about treating AIDS patients, and were more apprehensive of the disease in the course of treatment than the freshmen and juniors did. The above-mentioned findings suggested thai every individual should be cautious not to develop AIDS, as there is still no workable vaccine. Since the nation is not free from the horrible disease, the government should put more efforts into researching and preventing it. But what's most important is that dental-hygiene students, who will be committed to dental treatment in the future, should precisely be cognizant of the seriousness of that disease, and try to stay away from it by using protective devices and handling dental supplies properly. And the type of treatment system thai could prevent AIDS infection should be established.

• 대한교통학회지
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• 제32권2호
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• pp.93-105
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• 2014

본 연구는 자료포락분석(Data Envelopment Analysis: DEA) 기법을 활용하여 도로이동오염원 저감대책의 상대적 효율성 평가와 그에 기반하여 우선순위를 결정하였다. 현재 시행 중이거나 장래 계획 가능한 도로이동오염원 저감 대책들을 근거로 실효성 높은 자동차 온실가스와 대기오염물질 저감 대책 10개를 선정하여 시나리오를 구성하였으며, 대기오염물질 4개(CO, HC, NOX, PM), 온실가스 3개($CO_2$, $CH_4$, $N_2O$)물질에 대해 장래 통행패턴을 고려한 교통수요예측모형과 가변적 복합배출계수를 활용하여 2027년도를 최종 목표년도로 저감량을 산정하였다. 저감 대책들 간의 상대적 효율성을 평가하기 위해 DEA모형 중 초효율성 분석을 수행한 결과, 승용차 요일제 참여 확대 대책이 효율성 점수 1.879로 가장 우선순위가 높은 저감대책으로 선정되었으며, 버스전용차로 확대, CNG버스 보급 대책의 효율성이 높은 것으로 분석되었다. 본 연구의 결과는 자동차 온실가스와 대기오염물질 저감대책 우선순위 선정 결정 시 절대적인 자료로 활용될 수는 없지만 저감대책의 방향성을 제시하고 있으므로 향후 자동차 배출량 저감 정책방향 설정 및 체계적인 중장기 저감대책 수립에 기여할 수 있을 것으로 기대된다.

• Radiation Oncology Journal
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• 제8권2호
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• pp.199-205
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• 1990

1978년 1월부터 1987년 12월 사이에 연세대학병원 치료방사선과에서 근치적 방사선치료를 받았던 44예의 T2NOMO 병기의 성문암 환자중 후향적 분석이 가능하였던 42예의 환자의 최소 추적기간은 3년 이었으며, 5년 추적조사 기간은 $81\%$에서 가능하였다. 전체 환자(42예)의 5년 생존율 및 무병생존율은 각각 $63.1\%$ 및 $53.3\%$이었다. 5년 무병 생존율을 기초로한 성문의 운동성 장애와 성문암의 국소 침윤정도에 따른 예후인자의 분석에 있어서 성문의 운동성이 정상이고 성문 하부로의 침윤이 존재하지 않은 14예의 환자의 5년 무병생존율은 $83.1\%$로 방사선 치료만으로도 성문의 운동성 장애가 있거나 성문 하부 침윤이 있었던 경우에 비하여 월등히 높은 치료 성적을 나타내어 T2NOMO 병기 내에도 방사선 치료에 다양한 반응을 보이는 아군 (subgroup) 이 존재함을 알 수 있었고 아울러 치료 실패 양상, 선량-반응 관계, 치료 실패환자의 수술요법 등에 관한 분석을 하여 향후 치료의 지침으로 삼고자하였다.

• 한국언론정보학보
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• 제56권
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• pp.219-236
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• 2011

한국에서는 19세기 말부터 영어 신문들이 창간되었다. 한국의 소식과 국제 문제에 대한 한국의 의견을 외국인들에게 알리기 위해서다. 그 중 하나인 코리언 리퍼블릭(코리아 헤럴드 전신)은 1953년 8월 15일에 만들어져, 한국 외교 정책의 도구로 쓰였다. 당시 한국 전쟁 휴전협정이 조인되면서, 국제 정세는 복잡하게 전개되고 있었다. 이러한 외교 무대에서 이승만 대통령은 한국의 입장을 이 신문에 강력히 반영했다. 이는 오늘날 친숙한 미디어 외교 이론이 나오기 전에 이미 미디어를 통해 중요한 외교 안건이 다뤄졌음을 시사한다. 이 논문은 국제무대에서 논의되는 한국 문제에 능동적으로 참여한 영어 미디어에 대한 연구다. 창간 이후 1년간의 사설을 분석한 결과, 코리언 리퍼블릭은 한국이 북진 통일을 목표로 미국으로부터 최대한의 군사 및 경제 원조를 받아야 한다고 주장했다. 또한, 이 영어 신문은 한반도의 자유민주주의 체제를 지향했으며, 재무장을 통한 일본의 팽창주의를 경계했다. 무엇보다 독도문제 등에 있어서, 한반도 수역에 관한 한국의 주권을 강조했다. 다자간 외교에 관해서는 당시 사회주의 입장이 우세한 국제여론이 전후 한반도 문제를 처리하던 정치회담에 반영되는 것을 우려했다.

• The International Journal of Costume Culture
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• 제2권2호
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• pp.97-118
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• 1999

Ever since China adopted a free market economy, it has been basking in unprecedented economic growth. It has now emerged as one of the most promising markets in the world for the near future. The purpose of this study was to investigate of Chinese and Korea college female students's cognitive body type and to suggest basic informations for high quality clothing merchandising for china export. The subjects in this study were 430 college female students, aged from 18 to 24 living in Beijing(215) and Seoul(215). The survey were taken from June to July, 1999. SAS(Statistical Analysis System) is used for frequency, percentage, average, standard deviation, χ²-test. The results of this study are as follows. The 90% of Chinese collge female students has under 4000 yuan for monthly income, and they consume less than 1000 yuan for clothing purchasing for one year. About 42% chinese students are interested in controlling of physical body shape. The Korean college female students has from 1,000,000 won to 10,000,000 won for monthly income, and the 84% of them consume less than 1,000,000 for clothing purchasing for one year. It represents of economical difference between China and Korea. Examination on the Korean and Chinese self-perception on obesity of the body as a whole showed that both groups perceived themselves as normal or slightly overweight. More Korean respondents regarded their weight as normal than the Chinese did. The Chinese female college students perceived themselves rather overweight, and held a lower satisfaction level about their physical construction. While the Korean female college students showed low satisfaction level about specific bodily parts, they held a normal level of satisfaction about their physical construction as a whole. It is noteworthy that more Chinese respondents generally held lower satisfaction impressions about their physical construction than their Korean counterparts. It is needed to different merchandising project for export clothing in China.

• 한국보건간호학회지
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• 제2권2호
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• pp.45-61
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• 1988

Clonorchiasis should be realized as an important public health problems in Korea by their wide distribution, high prevalence rate and heavy infection intensity. This study was designed to obtain the infection rate, contributing factors as well as the behavior of infected persons among the factory workers in Pohang area where that parasite still remains as a problem. Study was undertaken from September '86 to October '87. Clonorchiasis skin test was performed for 3180 factory workers, and stools of skin test positive reactors were examined. Praziquantel was prescribed to stool examination positive persons for clonorchis sinensis ova. After one year. stool examination was repeated for them who received medicine. At the same time. a structured questionnaire was given and the results were analyzed and compared with control group. The results of this study are summarized as follows; 1. The infection rate of Clonorchis sinensis. 1) Clonorchiassis skin test positive rate was $26.2\%$ (834/3180). 2) Stool(Clonorchis sinensis ova) positive rate among skin test positive reactors was $21.6\%$ (129/598) All 129 infected persons were male. 2. Contributing factors of Clonorchis sinensis infection. 1) The chance of infection was higher in low-educated peple(p<0.01) 2) Stool(Clonorchis sinensis ova)positive rate was higher among the persons who reside near the riverside now(p<0.01), or among the persons who long history of riverside residence(p<0.01) 3) The infection rate was higher in thoes who like sliced raw fresh water fishes than in those who like cooked fishes(p<0.05). 4) Correct answering rate for questions about the cause and route of Clonorchis sinensis infection was low in infected persons. 5) The infection rate was lower among those who had experience of previous clonorchiasis test(p<0.01). 6) Family members of infected persons show higher rates of infection(p <0.01). 3. Treatment effect and compliance of infected person to treatment. 1) After one year, negative stool conversion rate was $85.4\%$. 2) $70.8\%$ of infected persons took the medicine; Only $3.1\%$ of them consulted to physician to know the medication effect; As many as $29.4\%$ of them continued to consume raw fresh water fishes. As a conclusion, City of Pohang area, Hyung San River in the center, is an endemic area of clonorchiasis. Current clonorchiasis control system seemed to be ineffective; many of the skin test positive group did not submitted their stool for examination; only $70.8\%$ of infected persons took the medicine even though the drugs were given free of charge; $29.4\%$ continued to consume raw fresh water fishes after taking medicine. Therefore. proper education program should be provided to improve the compliance to treatment. Follow-up for infected cases is mandatory to prevent waste of restricted budget.

• Brain Tumor Research and Treatment
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• 제6권2호
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• pp.60-67
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• 2018

Background Recently, modern technology such as diffusion tensor imaging (DTI), neuro-navigation and intraoperative neurophysiological monitoring (IOM) have been actively adopted for the treatment of thalamic tumors. We evaluated surgical outcomes and efficacy of the aforementioned technologies for the treatment of pediatric thalamic tumors. Methods We retrospectively reviewed clinical data from 37 children with thalamic tumors between 2004 and 2017. There were 44 operations (27 tumor resections, 17 biopsies). DTI was employed in 17 cases, neuro-navigation in 23 cases and IOM in 14 cases. All diagnoses were revised according to the 2016 World Health Organization Classification of Tumors of the Central Nervous System. Progression-free survival (PFS) and overall survival (OS) rates were calculated, and relevant prognostic factors were analyzed. The median follow-up duration was 19 months. Results Fifteen cases were gross total resections (GTR), 6 subtotal resections (STR), and 6 partial resections (PR). Neurological status did not worsen after 22 tumor resections. There were statistically significant differences in terms of the extent of resection between the groups with DTI, neuro-navigation and IOM (n=12, GTR or STR=12) and the group without at least one of the three techniques (n= 15, GTR or STR=9, p=0.020). The mean PFS was $87.2{\pm}38.0$ months, and the mean OS $90.7{\pm}36.1$ months. The 5-year PFS was 37%, and the 5-year OS 47%. The histological grade ($p{\leq}0.001$) and adjuvant therapy (done vs. not done, p=0.016) were significantly related to longer PFS. The histological grade (p=0.002) and the extent of removal (GTR/STR vs. PR/biopsy, p=0.047) were significantly related to longer OS. Conclusion Maximal surgical resection was achieved with acceptable morbidity in children with thalamic tumors by employing DTI, neuro-navigation and IOM. Maximal tumor resection was a relevant clinical factor affecting OS; therefore, it should be considered the initial therapeutic option for pediatric thalamic tumors.

• Tuberculosis and Respiratory Diseases
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• 제43권5호
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• pp.709-719
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• 1996

연구 배경: 비소세포 폐암의 근치적 치료는 수술적 절제에 주로 의존하고 있고 근치적 수술을 받은 환자의 예후는 수술당시의 병기가 중요하며 진행된 병기의 환자일수록 총 생존기간 및 무병생존기간이 현저하게 단축됨이 많은 연구자에 의해 보고되었다. 또한 근치적 수술 후의 재발은 수술부위보다는 원격 전이에 의한 재발이 많으므로 수술 후의 생존율을 향상시키기 위해서는 원격전이에 의한 재발을 억제할 수 있는 효과적인 수술 후 보조요법이 필요하다. 수술 후의 보조요법은 방사선 치료 및 항암제 투여가 있으나 각각의 치료 방법에 따른 생존율의 보고는 연구자에 따라 상이 한 결과를 보이고 있으며 국내 연구보고는 거의 없는 실정이다. 이에 연구자등은 1990년 1월부터 1995년 12월까지 연세대학교 의과대학 부속 세브란스 병원 흉부외과에서 근치적 절제술을 시행받은 282 명의 비소세포 폐암 환자를 대상으로 수술 후 보조요법의 효과 및 예후인자에 대한 분석을 시행하였다. 방법: 후향적 연구였으며 환자의 생존율은 Kaplan-Meier방법으로 분석하였다. 환자생존에 영향을 미치는 예후인자에 대한 분석은 Cox regression model에 의한 단일 및 다중 변수분석에 준하였다. 결과: 대상 환자의 조직학적 유형으로는 편평상피암이 166예(59%), 선암이 86예(30%), 편평상피선암이 11예(3.9%), 미분화 거대세포암이 19예(7.1%)이었다. 병기는 TNM분류에 따라 l기 93명, II기 58명, IIIa기 131명이었다. 수술 후 재발한 환자는 139명이었고 국소 재발이 28예(20.1%), 원격전이가 111예(79.9)이었다. 병기에 따른 5년 생존율은 I기 50.1%, II기 3 1.3%, IIIa기 24.1%였고(p<0.0001) 병기에 따른 중앙 생존 기간은 I기 55개월, II기 27개월, IIIa기 16개월로 나타났다(p<0.0001). IIIa병기의 환자중 수술 후 항암제만을 투여받거나 항암제와 방사선치료를 받은 환자는 81명이었고 이들의 중앙 생존 기간은 19개월이었으며 수술만을 받거나 수술후 방사선 치료만을 받은 환자는 50명이었는데 이들의 중앙 생존 기간은 14개월로서 양군간에 통계적으로 유의한 차이는 없었다(p=0.2982) 또한 IIIa 병기의 환자중 수술만을 받은 환자는 11명이었고 이들의 중앙무병 생존기간은 4개월이었으며 수술후 항암제 투여만을 받은 환자는 21명이었고 이들의 중앙무병 생존기간은 16개월로 양군간에 통계적으로 의미있는 생존기간의 차이를 보였다(P=0.0494) IIIa 병기중 N2기의 환자는 92명으로 5년 생존율은 25%, 중앙 생존 기간은 15개월이었다. 이들 중 수술 후 항암제 투여군은 62명으로 중앙 생존 기간은 18개월이었고 비투여군은 30명으로 이들의 중앙 생존기간은 14개월이었으며 양군간에 통계적으로 유의한 차이는 없었다(p=0.3988). N2기 환자중 수술후 방사선 치료를 받은 환자는 66명으로 이들의 중앙 생존 기간은 16개월이었고 방사선 치료를 받지 않은 환자는 26명으로 이들의 중앙 생존 기간은 14개월이었다. 양군간에 통계적으로 유의한 생존 기간의 차이는 없었다(p=0.6588). Cox Multiple Regression Model을 이용하여 수술 후 환자의 생존율에 영향을 미치는 예후 인자에 대하여 분석한 결과 환자의 연령(p=0.0093)과 병기(p<0.0001)만이 통계적으로 유의하였다. 결론: 비소세포 폐암 환자의 연령과 병기가 유의한 예후 인자이었으며, 보조 요법에 따른 생존율에 유의한 차이는 없었다. 따라서 수술 후 환자의 생존율을 향상시키기 위해서는 더욱 효과적인 보조요법의 개발이 필요할 것으로 생각된다.