인터넷 비지니스와 전개방향

윤문길,최기철 한국항공대학교 경영연구소 1997 경영연구 Vol.4 No.1

The wide spread af Internet has motivated the introduction af various application on the communication network, and activated the network usage. The Internet represents in miniature a model for the new communications industry of the Zlst Century. By examining the structure of the marketplace which the Internet model represents, companies am make sense of sometimes apparently confliction trends now taking place in the telecoms, IT and broadcasting/publishing sectors. In this paper, new business opportunities on the Internet are surveyed and analyzed for increasing the revenue of telecoms. Discussing with the future trend of Internet business, some strategic schemes for telecoms are suggested to cope with the new business environment evolving on the cyber space.

우리나라 금융기관의 전략적 고용조정 방안에 관한 연구

전상길,최문경 한양대학교 서해경제연구소 2000 서해경제연구 Vol.5 No.-

This study aims to develop a conceptual model on the strategic employment adjustment in Korean financial institutes. The model basically rooted in gaining competitiveness in financial institutes, proposes the criteria of direction, scope, speed and finally objects of employment adjustment with some theoretical background. Specifically, according to this paper, first, the decision of the direction of employment adjustment should be based on the criteria of technical rationality(business fit and internal fit). Second, the decision of the scope of employment adjustment had to be rooted in strategic uncertainty of industry driving force. Thirdly, the decision of the speed of employment adjustment mainly dominated by the degree of required innovation. Finally, as a critical issue, the decision of the objects of employment adjustment shuuld be depend on the business domain in the future and strategic posture to reach out there. Some discussions and implications are also suggested.

인발 성형 공정을 이용한 carbon-glass hybrid composite 제작

박상윤,최원종,강길호,문초록,김세영 한국항공대학교 항공우주산업기술연구소 2002 航空宇宙産業技術硏究所 硏究誌 Vol.12 No.-

단면이 일정한 구조용 복합재료 제조공정에 널리 사용되고 있는 pultrusion 공정을 이용하여 glass-carbon fiber hybrid composite을 제조하였다. 열분석을 통하여 모재의 경화온도와 경화시간을 분석한 후 금형의 온도와 pulling speed를 결정하였다. 다양한 섬유 비율의 hybrid composite를 제작하였으며 flexural modulus를 측정한 결과 rule of mixture를 이용한 예상치 보다 높은 값을 보였다. Glass-carbon hybrid composite was manufactured by pultrusion process. The major processing conditions such as temperature of heating die and pulling speed have been fixed from thermal analysis results. Hybrid composites with various carbon fiber content were manufactured and flexural modules of each hybrid composite as measured. Compare with rule of mixture, positive hybrid effect was observed.

Sinus lifts in the presence of pseudoantral and mucous retention cysts

Moon Gi Choi,Chang Hyun Hong,Eun Joo Choi,Won Jong Park,Young Geun Kim,Do Geon Gil 대한구강악안면외과학회 2022 대한구강악안면외과학회지 Vol.48 No.2

Objectives: Mucous retention cysts and pseudoantral cysts are mainly located within the floor of the maxillary sinus. Most of these maxillary cysts are asymptomatic and often only require observation. However, the presence of these benign maxillary cysts may create problems when maxillary sinus all types of implants are needed. Various treatment methods have been introduced. The selected treatment option depends on the type, size, and location of the cyst and its symptoms. Patients and Methods: The case reports of four patients with maxillary cysts were reviewed retrospectively. These patients received a sinus lift be-tween January 2016 and October 2021 at the Wonkwang University Dental Hospital. Results: To reduce unnecessary operations and the duration of treatment, a conservative treatment method is required. A sinus lift in the presence of maxillary cyst will not typically cause sinus problems if the lifted sinus membrane does not interfere with ventilation of the maxillary sinus. Conclusion: When proper treatment is provided, sinus perforation during a sinus lift performed in the presence of maxillary cyst and contamination of bone graft materials by cystic fluid does not necessarily result in adverse outcomes.

Characteristics of Salt Tolerance in Several Tree Species

Moon Gil Choi 한국산림과학회 1989 한국산림과학회지 Vol.78 No.1

The purpose of this dissertation is to compare the characteristics of salt tolerances of several planting tree species in Korea. This study was carried out by investigating the woody plant distribution as related to salt concentration of soil in eastern coastal forest in Korea, and the histological changes and physiological responses of leaves as related to various salt concentration treatments. The results gained are as follows 1. In eastern coastal forest in Korea, Pinus thurzbergii was distributed as dominant species within the area from beach line to 200 meters inland : Pinus densiflora within from 200 meters to 300 meters. Pinus thunbergii was distributed as dominant species within the area up to 50 meters in altitude from sea level, and Pinus densiflora above 50 meters in altitude. 2. The NaCl concentration of soil in eastern coastal forest decreased in proportion to the distance from beach line and altitude from sea level, but increased in proportion to the depth of soil. The density of Pines thunbergii increased in the place where NaCl concentration was more than 100 vpm in eastern coastal forest soil and the density of Pines densiflora increased where that was lower than 100 vpm. 3, The most tissues of leaves being damaged with salt were dyed red by safranine as compared with the intact tissues. Assimilation tissue (mesophyll) and conductive tissue (endodermis, transfusion tissue, and bundle sheath) damaged with salt were transformed or collapsed or shrinked. 4. The water potential of leaves damaged with various salt concentrations did not change nearly within 10hours after salt treatment. However, the higher salt concentration in soil appeared, the higher leaf water potential was as dates elapsed after salt treatment. Leaf water potential of intolerant species was higher as compared with the tolerant species because of the severe dehydration from the cell. 5. By the water relations parameters obtained from P-V curves, when leaves were damaged by the various salt concentrations, π_O, and π_P. were higher and V_P/V_O, and Emax were lower as compared with the intact leaves. 6. The photosynthesis rate of leaves was decreased by increasing the salt concentration in soil and decreased gradually in proportion to the salt tolerance of the species. By comparison to the reduction of photosynthesis rate, the degree of relative tolerance to the salt damage was in the follow ing order : Pines thunbeygii $gt; Pines densifloya $gt; Buxus koreana $gt; Fraxinus mandshuriea $gt; Betula platyphylla var, japonica $gt; Larix leptolepis. 7. In relatively low salt concentration in soil (lower than 0.2%), the seed germination rate was not nearly affected, however, in relatively high salt concentration it was decreased by increasing the salt concentration in soil, 8, The degree of relative salt tolerance based on seed germination rate after salt treatment was highest in Pines thunbergii and Fraxinus rhynchophylla ; medium in Pines densiflora, Pines strobes, Pines rigida × taeda F₁, and Pines rigida ; lowest in larix leptolepis, Betula platyphylla var, japonica, and Buxus koreana. 9. The symptoms of salt damage appeared first in lower portion leaves and then spread toward the upper portion leaves. The visible damage of leaves varies among genera and species. 10. By increasing the salt concentration in soil, not only the first symptom of salt damage of the seedlings appeared earlier, but also the amount of salt damage was increased. The degree of relative salt tolerance to salt concentration in soil was in the following order : Plnus thunbergii $gt; Pinus rhgida $gt; Pinus densiflom $gt; Pines koraiensis $gt; Lariz leptolepis in conifers ; Fraxinus rhynchophvlld $gt; Frarinus mandshurica $gt; Buxus koreana $gt; Betula platyphylla var, japonica in broad-leaved trees. 11. Generally, the evergreen coniferous trees were more tolerable to the wind-blown salt than the deciduous broad-leaved trees. In conifers, Pines thunbergii and

Characterization of Supported Cobalt Catalysts by TPR and TPD

Choi, Hyeong Ki,Choi, Jong Oh,Choi, Jeong Gil,Jung, Moon Ki,Oh, Hyun Gyun 한국공업화학회 1997 Journal of Industrial and Engineering Chemistry Vol.3 No.3

The surface properties of cobalt catalysts supported on A1₂O₃, SiO₂, and TiO₂ were investigated using temperature-programmed reduction and desorption. Effects of different supports, metal loading, and preparation condition on cobalt catalyst properties were also evaluated. The activation energy of reduction increased in the following order: Co/TiO₂<Co/A1₂O₃<Co/SiO₂. For different metal loadings, the catalyst with the lower loading was less readily reducible than that with the higher metal loading. This was confirmed using the results from measurements of particle size, amount of CO desorbed and catalytic activity. While carbon monoxide adsorption at room temperature produced four carbon monoxide desorption peaks for Al₂O₃-supported cobalt catalyst, one carbon monoxide desorption peak was observed for cobalt catalysts supported on SiO₂ and TiO₂. Based on the results on the amount of carbon monoxide desorbed, it was considered that multiple desorption peaks on Co/A1₂O₃ catalyst might be due to the morphological changes between cobalt oxide and alumina support, and the stabilization of Co^(2+) by SiO₂ support and the concept of SMSI (strong metal-support interaction) were suggested to explain the results for Co/SiO₂ and Co/TiO₂ catalysts, respectively.

도축 한우의 복강내 지방괴사증 발생과 병리조직학적 연구

최길성 ( Gil Seong Choi ),임채웅 ( Chae Woong Lim ),채효석 ( Hyo Seok Chai ),최인열 ( In Yeol Choi ),이성효 ( Sung Hyo Lee ),김추철 ( Chu Cheul Kim ),서문정 ( Moon Jeong Suh ) 한국가축위생학회 1999 韓國家畜衛生學會誌 Vol.21 No.1

The bovine fat necrosis is often seen as an incidental lesion in the adipose tissues of the abdominal cavity. Most of affected animals, however, have been detected at the slaughter house or routine necropsy. The purpose of this study was to examine the occurrence and distribution of abdominal fat necrosis in Korean native cattle, and its pathologic features. Postmortem inspection at an Chonju abattoir during a three-month period in 1997 detected at necrosis lesions in 67(6.6%) of the 1,012 animals received for slaughter. The occurrence was mainly in alimentary tracts and perirenal. Both sexes were affected, but the lesions were predominantly occurred in female. Gross lesions were white or yellowish in color and formed hard lumps irregular in shape ranging from small nodules to large solid masses. On the cut surface, lesions were occasionally seen chalky calcified granules and some of the lesions contained oil-like fluid. The surface of irregular shaped masses constricted kidneys and intestinal loops. Microscopically, the masses were encapsulated by thickened fibrous tissue, which infiltrated deeply and divided them into many irregular lobules. Initial lesions presented mild inflammatory cell and fibrous proliferation. It became fibroplasia in progressive lesions and resembled chronic lesion, eventhough no grossly apparent inflammatory reaction. The hard consistency of masses, due to fibroplasia, can compress the intestines, urinary organs, and reproductive organs.

XR 기술을 활용한 소방안전관리자의 교육⋅훈련 필요성에 관한 연구

최문석(Moon Seok Choi),최유정(Yoo Jeong Choi),최수길(Su Gil Choi),김태희(Tae Hee Kim),김시국(Si Kuk Kim) 한국화재소방학회 2022 한국화재소방학회 학술대회 논문집 Vol.2022 No.춘계

TTA 정보통신용어사전에 따르면 XR이란 “증강현실(AR), 가상현실(VR), 혼합현실(MR)을 아울러 사용자에게 경험과 몰입감을 제공하는 초 실감형 기술”이라 정의되어 있다. 즉, XR 기술은 가상의 공간과 사물을 인간의 오감을 활용해 직접 경험하지 못하는 상황을 간접으로 체험할 수 있도록 하는 VR과 현실의 이미지에 가상의 부가 정보를 실시간으로 덧붙여 보여주는 AR 등의 기술을 이용하여 현실 공간에 배치된 가상의 물체를 활용해 체험할 수 있도록 하는 기술이라 할 수 있다. COVID-19 이후 비대면 기술이 관심을 받으면서 XR에 관한 관심도 높아졌으며 전 세계적으로 게임, 제조, 의료, 문화, 국방 등 다양한 분야에서 사용되고 있으며 주로 교육 및 훈련의 용도로 활용되고 있다. 특히 소방 현장 지휘관을 위한 훈련 시스템이나 화재현장 대응 대원을 위한 훈련 시스템 등 소방분야에서도 XR을 활용하여 훈련 및 교육을 진행하고 있지만, 소방안전관리자를 위한 교육⋅훈련 시스템은 아직 개발되지 않았다. 이에 본 연구에서는 기존의 XR 기술을 활용한 교육⋅훈련 시스템을 조사하여 소방안전관리자용 XR 훈련의 필요성을 도출하였다. 주요 결과로 현재 XR 기술을 활용한 교육⋅훈련 시스템은 훈련을 위한 장비가 고가이거나 반복적인 훈련을 통해 높은 수준의 숙련도가 필요한 분야에서 활용하고 있으며 특히 화학사고 대응훈련과 같이 실제 경험하기 어려운 상황에 대응훈련이 이루어지고 있다. 이처럼 XR 교육⋅훈련은 훈련에 드는 비용과 인력을 줄일 수 있으며 훈련상황에서 벌어지는 안전사고 위험을 최소화할 수 있으며 실제 경험하기 어려운 상황에 대한 대응훈련이 가능할 것으로 나타났다.

수종간의 (樹種間) 내염력특성에 (耐鹽力特性) 관한 연구 (Ⅲ) - 몇 수종에 대한 염분처리가 엽의 생리적 반응에 미치는 영향 -

최문길 ( Moon Gil Choi ) 한국산림과학회 1988 한국산림과학회지 Vol.77 No.4

The purpose of this study was to investigate the physiological response to salt treatments in the leaves of several tree species. The results obtained were as follows : 1. The water potential of tree leaves damaged with various salt concentrations did not change nearly for 10 hours after treatment. As time elapsed after treatment, however, the higher salt concentration in soils, the higher leaf water potential was observed. 2. Leaf water potential of species intolerant to salt was higher than tolerant species due to the severe dehydration from cells. 3. According to the water relation parameters obtained from P-V curves, the values of π_σ and π_ρ in the damaged leaves were higher, but those of Vρ/Vσ and Emax were lower than those of the intact leaves. 4. The photosynthesis rate of tree leaves decreased remarkably with increasing the salt concentrations in soils, and it decreased faster for species intolerant cintolerant to salt.

Improved Fruit Quality and Yield when Melons and Cherry Tomatoes were Grown in the Air-dome Greenhouse Compared to the Commonly Used Iron-frame Polyethylene Cover Greenhouse

Hyo Gil Choi,Jae Han Lee,Byoung Yong Moon,Joon Kook Kwon,Gyeong Lee Choi,Seung Hwa Lee,Nam Jun Kang 경상대학교 농업생명과학연구원 2017 농업생명과학연구 Vol.51 No.4

This study was carried out to explore possibilities of cultivating horticultural crops in the air-dome greenhouse in comparison to the common iron-frame greenhouse as the standard. The levels of carbon dioxide and atmospheric pressure measured inside the air-dome greenhouse turned out to be higher than those measured inside the iron-frame greenhouse. Contrastingly, light intensity was relatively weaker inside the air-dome greenhouse due to the air-inflated double layers. Plants of melon and cherry tomato were cultivated from May 2 to August 12, 2016, respectively in the two greenhouses. For melon plants, growth in the air-dome greenhouse effectively increased fruit weight as well as trunk circumference compared to iron-frame greenhouse. Moreover, soluble sugar content of melon fruit was significantly higher when cultivated in the air-dome greenhouse. For cherry tomato plants, fruit yield of cherry tomato was significantly increased inside the air-dome greenhouse. Furthermore, it has been found that the air-dome greenhouse was considerably effective in shortening the growing period of melon and cherry tomato plants in comparison to the iron-frame greenhouse.