• Journal of Korean Ophthalmic Optics Society
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• v.12 no.3
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• pp.1-5
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• 2007

This is a succeeding article of J. Korean Optalmic Optics Society vol. 11(2) pp. 121-129(2006) [Research about the distribution of refractive errors in distinction of gender and at age of Kyonggi province's partial area]. The former article showed age-specific distribution of myopia, hyperopia and astigmatism which generally appears in refractive errors. This paper aimed to investigate the change of refractive power and prevalence of refractive errors by age. Total 928 subjects were sampled and their refractive errors were determined using auto refractometer. As the results, change of refractive power of subjects appeared at the age about 40, and suddenly reduced over 46 years resulting in (+)refractive power at their fifties. Relative risks of refractive errors of myopia increased in younger subjects but the risks decreased in older subjects (over 46 years). On the other hand, the risks of hyperopia decreased as the age of subjects increase, but could increase to 0.24 (95% CI: 0.07-0.88) after 36 years. This results showed that presbyopia might progress more early when people were before 40 years.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1992.04b
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• pp.581-591
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• 1992

최근 급속한 사무자동화와 함께 컴퓨터의 사용이 보편화되어 가지고 있다. 이에 따라 컴퓨터등 VDT에 매달려 일하는 사무직 근로자들이 시력장해, 두통, 어깨결림, 요통, 스트레스성 장애등 새로운 질병에 시달리고 있다. 이것은 "VDT증후군"(Visual Display Terminal Syndrome) 또는 "VDT병"이란 신종 직업병이다. 컴퓨터 수상기 화면을 계속해서 들여다보면 화면에서 나오는 자외선과 강한 빛으로 눈에 무리가 와 충혈되고 침침해지며 두통 증세가 나타난다. 이런 초기증상이 6개월이상 계속되면 시력이 떨어지고 만성피로를 느끼는가 하면, 때때로 독감과 비슷한 증상이 나타나며, 심하면 탈모현상까지 경험하게 된다. 요즘 시행되고 있는 초등 고교 컴퓨터교육의 의무화와 2천년대의 1가구 1단말기 설치를 목표로한 컴퓨터 영상단말기의 급속한 보급으로, 앞으로는 사무실뿐만 아니라 일반 가정에까지 컴퓨터 이용이 일상화될 전망이고 보면 VDT작업에 따른 건강장해 문제는 더이상 가볍게 볼 수 없는 문제이다. 이에 대해 선진국에서는 작업시간 규제, 회사가 종업원의 정기적인 시력검진 및 시력교정에 필요한 비용을 보조하도록 하는가하면 실작업환경 개선등 다각적인 대책을 마련하고 있다. 미국, 유럽, 일본등 선진국에서는 VDT작업 여성들의 유산 및 기형아 출산등 임신이상에 관한 실태보고서까지 나오고 있어 여성들에게 커다란 충격을 던져주고 있다. 그러나 우리나라에서는 VDT병 증상을 호소하는 근로자들의 직업병예방 및 대책에 큰 어려움을 겪고있다. 그러므로, VDT작업으로 인한 건강상의 문제, 작업환경 및 작업자세등을 조사하여 문제점과 예방대책을 살펴보고, 작업장을 인간공학적으로 설계하고 평가하여 사용자의 건강을 보호하고 생산성의 향상에 도움이 되고자 한다.생산성의 향상에 도움이 되고자 한다.Action Code를 계산처리부로 넘겨준다. 입력처리부에서는 Mouse와 Keyboard 어느것으로나 입력이 가능하도록 해준다. 출력처리부에서는 Action Code에 따라 계산처리부에서 계산된 결과를 화면에 보여주기 위한 각종 2D/3D Graphic Routine들이 포함되어있어 계산처리부에서 불러쓰도록 되어있다.에서는 전문가시스템 기법을 도입해서 사출금형 공정계획전문가의 지식과 경험을 획득하여 지식베이스를 구축하고, 전문가시스템 셀(shell)중 CLIPS를 이용하여 자동공정계획시스템인 Mold CAPP을 개발하였다.PP을 개발하였다.며 이와 상이한 결과도 보여주고 있다. 이상으로 볼 때 1) 가정하수의 질을 높이기 위하여 분뇨정화조 의 효율증대 2) 산업폐수의 공정별 폐수량의 조절 및 폐수성 상에 따른 총량규제에 대비한 효율증대 3) 하천의 오염부하와 자정능력 최대한 부여 4) 폐수처리를 위한 미생물제개발 및 오염지표 종 연구와 오염내성 생물의 연구등이 종합적 으로 수행되어야 한다. 5) 이상의 모든 조사와 연구결과를 객관적으로 표기할 수 있도록 하천의 이정표가 정해져야 하겠다.7%)에 비해 유의하게 낮았고 정상군과는 유의한 차이를 보이지 않았다.상고나성이 있었다. 혈중 호모시스테인 농도는 질병의 위험요인으로서 뿐 아니라 대사적으로 밀접하게 연관된 비타민 영양상태의 biomarker로서도 그 영향력이 크다고 할 수 있다. 따라서 성별에 다른 다양한 연령집단에서 건강한 일반인과 심혈관계 질환자 등을 대상으로 호모시스테인과 비타민 영양상태에 대한 연구가 체계적으로 이루어 져야 할 것이다.태를 보다 효율적으로 증진시킬 수 있는 대안이 마련되어져야 한다고 사료된다.$\ulcorner$순응$\lrcorner$의 범위를 벗어나지 않는다. 그렇기 때문에도

• Horticultural Science & Technology
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• v.32 no.2
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• pp.184-192
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• 2014

Various types of unit packaging methods were applied for 'Fuji' apples during short-term cold storage and export simulation. Gas tightness of the package was controlled stepwise in the successive two-year experiments using different perforation treatments (none, punch hole, or pinhole) and sealing methods (tie v s. heat seal). Risk of tight packaging and effectiveness of macroperforation on weight loss and quality maintenance were analyzed as related to changes in gas concentration inside the packages. Immediately after harvest, each 5 apple units were packaged in $40{\mu}m$ polypropylene (PP) film bags, stored 4 weeks at $0^{\circ}C$, and then put on the shelf for one week at ambient temperature in the preliminary experiment, In the main experiment, export process was imposed after storage simulating 2 week refrigerated container shipment at $0^{\circ}C$ plus one week local marketing at ambient temperature. Non-perforated film packaging with relatively high gas tightness induced flesh browning caused by carbon dioxide accumulation regardless of the sealing methods. Among perforated film packaging, in contrast, atmospheric modification was partly established only in the pinhole treatment and flesh browning symptom was not observed in all the treatments. Even the punch hole perforated film packaging without gas tightness effectively reduced the weight loss, whereas had slight benefits for quality maintenance. Reduced perforation using pinhole treatment seemed to improve sensory texture, while effects on physicochemical quality were insignificant. Overall results suggest the need of more minute perforation treatments on the packaging film to ensure modified atmosphere effects on quality maintenance.

• The Journal of Industrial Distribution & Business
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• v.9 no.12
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• pp.45-53
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• 2018

Purpose - The purpose of the study was to investigate operation system of current convenience store and competing retail store and to find out development of unattended convenience store. Operators can save labor cost and solve labor seeking when opening shop under suitable environment and commerce area, and assure of employee's safety. Customers are allowed to select commodity comfortably without disclosure of face and to shorten standby time at simple store opening, buying and paying and to produce convenient living environment by financing, delivery and goods control. This study examined effect and problems of operation of existing and unattended convenience store from point of view of visual merchandising to find out model of unattended convenience store and to strengthen competitiveness of convenience store business. Research design, data, and methodology - Research procedure of accomplishment of goal of the study was: The study investigated state of distribution business, and role and definition of VMD. First, VMD played an important role of promotion and competitiveness of unattended convenience stores. Second, the author investigated research and cases of unattended convenience stores 14 months, that is to say, from August 15, 2017 to October 15, 2018. Third, the author investigated on-the-spot three of common convenience stores, three of unattended convenience stores and three of retailers one month, that is to say, June 1, 2018 to July 1, 2018. The subject was convenience stores and retailers selling similar type of products at Seoul and metropolitan area. Results - Layout, selling place, brand identity, goods assortment, authentication system, product information cognition and control, buying and payment system, security system, salesmen, promotion and other services should be improved from point of view of merchandising. Structure, furniture, lighting, voice, façade, VP, PP, IP and POP should be developed. Conclusions - Unattended convenience stores saved operating cost and lessened labor and gave visitors convenience and comfortable shopping and made use of resources effectively. Further studies with quantitative analysis shall find out strategic conditions for promotion of unattended convenience stores.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.94-103
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• 2016

This study was conducted to investigate the association of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) with all-cause mortality among populations. The data used were from a Korean Genome and Epidemiology Study (KoGES) based on health examinations and questionnaires. The subjects consisted of 10,110 persons aged 40 and over. Hazard ratio was analyzed using Cox's proportional hazard model. The hazard ratio of AST (${\geq}50.0\;IU/L$) was 2.198 (95% CI: 1.217-3.971) after being adjusted for age, sex, education, regular exercise, smoking, drinking, WHR, and TG. In conclusion, AST was an independent significant risk factor of all-cause mortality, and ALT showed a tendency to increase. Overall, these findings indicate that AST and ALT may be useful tools for predicting mortality.

• Polymer(Korea)
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• v.38 no.4
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• pp.550-556
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• 2014

Recently, the peptide(or protein)-polymer hybrid materials (PPs) were sought in many research areas as potential building blocks for assembling nanostructures in selective solvents. In PPs, the facile routes of preparing well-defined peptide-polymer bio-conjugates and their specific activities in various applications are important issues. Our strategy to prepare the peptide-polymer hybrid materials was to combine atom transfer radical polymerization (ATRP) method with solid phase peptide synthesis. The standard solid phase peptide synthesis method was employed to prepare the PYGK (proline-tyrosine-glycine-lysine) peptide. PYGK is an analogue peptide, PFGK (proline-phenylalanine-glycine-lysine), which interacted with plasminogen in fibrinolysis. The peptide and the peptide-initiator were characterized with MALDI-TOF mass spectrometry and $^1H$ NMR spectrometer. The peptide-polymer, pSt-PYGK was characterized by GPC, IR, $^1H$ NMR spectrometer and TLC. Spherical micellar aggregates were determined by TEM and SEM. Current synthesis methodology suggested opportunities to create the well-defined peptide-polymer hybrid materials with specific binding activity.

• Journal of Chest Surgery
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• v.29 no.3
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• pp.271-277
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• 1996

In selected cases, early corrective surgery is indicated in the management of infants having large ventricular septal defects. The risk of any surgical procedure in infancy is acknowledged to be great and should be avoided whenever possible. However this greater surgical risk is justified when the patient presents with intractable congestive heart failure, severe pulmonary hypertension, marked growth retardation, and recurrent prolonged lower respiratory infections. We analyzed 31 patients with ventricular septal defect in infancy who underwent surgical correction from January 1991 through December 1994. Age ranged from 6 months to 12 months with mean age of 9.2 months. Of the thirty-one patients, 23 patients were male and 8 patients were female. Mean body weight was 7. 4kg. The most common type of ventricular septal defect was perimembraneo s (64.5%). Associated cardiac anomalies were found in 17 patients (55.8%). Mitral regurgitation was the most commonly associated cardiac anomaly (16.1 %) and followed by patent ductus arteriosus (12.9%). When cardiac catheterization data were analysed, the most common range of Qp/qs, RpiRs, Pp/ps were 2.1∼ 3.0, 1-0.25, above 0.70 respectively. Among the indications of surgical correction, there were pulmonary hypertension in 20 patients, congestive heart failure in 3 patients, intractable respiratory infection in 10 patients and growth retardation in 14 patients. The most common surgical approach and method for closure of ventricular septal defect .were right atriotomy (58%) and Dacron patch closure (94%). Postoperative complications occurred in 10 cases (32%) and overall mortality was 12.9% (4 cases). All operative deaths in this series occurred in infants under the age of 8 months and weight of 8 kilograms.

• Journal of the Korean Geotechnical Society
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• v.33 no.4
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• pp.35-46
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• 2017

Most of high carbon fly ashes (HCFA) are discarded in landfills with high costs due to low recycling rate. This study aims to explore the geotechnical behaviors of HCFA mixtures reinforced with fiber and sand. A series of compaction test, unconfined compressive strength test and modified 1D consolidation test with bender element were performed. Specimens were prepared at their optimal moisture contents based on the results of compaction tests. The results of this study demonstrate that the inclusion of fibers to the matrix of HCFA increases unconfined compressive strength (UCS), strain at UCS, and maximum shear modulus ($G_{max}$) at a given void ratio. Reinforcement with sand increases UCS of HCFA; while the strain at UCS is irrelevant with sand fractions. Sand particles may disrupt the direct contacts between HCFA particles at low sand content, resulting in a decrease in $G_{max}$. However, it can be expected that the mixtures with sand content larger than 20% are in dense state; thus, $G_{max}$ of HCFA reinforced with sand shows greater value than that of unreinforced HCFA compacted with the same energy. Regardless of types of reinforcement, the compression index ($C_c$) of both fiber and sand reinforced HCFA is mainly determined by initial void ratio.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.55-63
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• 2020

Road traffic noise is a major complaint. Porous pavement (PP) has been proposed as an effective method for reducing road traffic noise, but it has not been applied much due to the lack of quantitative evaluation. In this study, the noise reduction of single-layer porous pavement (SLPP) and double-layer porous pavement (DLPP) was evaluated. The noise was measured using the CPX method, and the driving speed was measured every 10km/h from 50km/h to 80km/h. The differences in noise level between the two PPs were statistically significant. The driving speed had no significant effect on the difference in noise between the two PPs. The DLPP showed a 6.6dB(A) reduction in average and a 6.3dB(A) reduction at the 95% confidence level compared to the SLPP. Reducing noise by 5dB(A) is equivalent to reducing traffic to 1/3 or lowering the vehicle's speed to 1/2. Sensitively, it is possible to recognize a 3dB(A) and 5dB(A) difference. The DLPP and SLPP were very effective in reducing traffic noise.

• The korean journal of orthodontics
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• v.39 no.5
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• pp.330-336
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• 2009

Objective: To examine the differences in lateral cephalometric characteristics between patients with dental protrusion and crowding in order to determine what factors affect dental protrusion or crowding while both malocclusion types are caused by large tooth size. Methods: Twenty nine individuals with dental protrusion and 22 individuals with dental crowding were enrolled in this study. All subjects had larger teeth than average and Class I molar relationships. Craniofacial characteristics and hyoid bone positions were determined from lateral cephalograms and compared between the two groups. Results: In the comparisons of craniofacial characteristics, the measurements indicating maxillary length and facial convexity showed greater values in the protrusion group than in the crowding group. Comparisons of hyoid bone positions showed that the hyoid bone was positioned more anteriorly and superiorly in the protrusion group than in the crowding group. Conclusions: The results of the present study indicate that some craniofacial characteristics and tongue position may affect the development of dental protrusion or crowding; when an individual has large teeth, dental protrusion or crowding might be determined according to maxillary growth and tongue position.