• 지능정보연구
• /
• 제23권3호
• /
• pp.45-67
• /
• 2017

"2016 인터넷이용실태조사"에 따르면 인터넷 이용자수 및 이용률은 점점 증가하고 있으며 접속방법에 있어서는 컴퓨터보다 스마트폰을 통한 접속이 많아지고 있다. 스마트기기의 증가에 따라 초고속인터넷의 수요가 감소할 것이라는 전망도 있다. 하지만, 스마트기기의 증가에도 불구하고 기가인터넷을 통한 속도 향상과 IoT 시장의 성장으로 인해 초고속인터넷 시장은 당분간 유지될 것으로 전망된다. 시장의 포화로 인해 통신사업자들이 신규고객 확보를 위해 과도한 경쟁을 하고 있지만, 고객이탈의 원인을 알 수 있다면 보다 효과적인 마케팅을 통해 과도한 마케팅비용을 절감할 수 있을 것으로 기대된다. 본 연구에서는 통신사업자 A사가 보유하고 있는 안양시, 군포시, 의왕시 3개 도시의 결합유형별 해지 데이터와, 통계청으로부터 구한 지역별 데이터를 결합하여, 지역별 해지율과 이에 영향을 미치는 지역특성간의 관계를 분석하고자 하였다. 특히 인접지역에 따라 결합유형별 해지율의 분포에 차이가 있을 것으로 보고, 클러스터링을 이용하여 해지유형이 유사한 지역을 도출 및 분석하고자 하였다. 공간검색통계도구인 SatScan은 기존의 클러스터링 방법에 공간정보를 추가하여 인접지역을 중심으로 군집이 형성되도록 한다. 따라서 본 연구에서는 SatScan을 이용해 지역의 공간정보를 기반으로 유사지역을 군집화하고, 군집별 해지율과 지역별 데이터와의 연관성을 분석하였다. 분석 단계에서는 먼저 공간정보와 해지데이터를 결합하여 도출된 군집들의 특성을 정리하였으며, 다음으로 군집분석 결과를 바탕으로 하여 각 동의 초고속 인터넷 해지율과 지역별 데이터와의 연관성을 분산분석, 상관분석, 회귀분석을 이용하여 분석하였다. 그리고, 분석결과를 기반으로 하여 지역에 따른 적절한 마케팅 방안을 제안하였다.

• 대한원격탐사학회지
• /
• 제33권6_2호
• /
• pp.1119-1137
• /
• 2017

본 연구는 서울과 경기도 지역 도시숲의 수자원 공급 생태계서비스와 기후완화 생태계서비스를 평가하였다. 생태계서비스를 자연기능기반 서비스, 산림의 자연기능과 인구분포를 고려한 생태계서비스, 산림의 자연기능과 수혜자 분포를 고려한 생태계서비스의 세 가지 서비스로 구분하여 평가하고, 이후 기후변화가 생태계서비스에 미치는 영향을 평가하였다. 평가 결과, 토지피복과 토양 등 자연조건을 반영한 도시림의 수자원 공급서비스의 경우, 경기도가 서울보다 높은 서비스를 제공하는 것으로 나타났으며, 지역별 인구분포를 추가적으로 반영한 서비스 평가에서는 인구가 많은 곳에서 서비스가 높게 나타나는 양상을 보였다. 그러나 도시림의 수자원 수혜자 분포를 추가로 반영한 수자원 공급 생태계서비스 평가 결과는 인구분포를 반영한 서비스 평가 결과와 공간적으로 다르게 나타났다. 같은 수원함양 기능을 가진 지역이라도 인구분포나 물 사용 수혜자의 분포가 많은 지역일수록 높은 서비스 결과가 나타났다. 또한 기후변화가 수자원 공급 생태계에 서비스에 미치는 영향을 평가한 결과, 기후변화에 따른 수자원 공급 서비스는 평균적으로 26%정도 줄어들어 전반적인 수자원 공급 생태계서비스가 낮아지는 경향을 보였다. 기후완화부문의 경우, 산림으로부터 가까운 거리에 있을수록 높은 온도저감 효과가 나타나 산림주변지역에서 높은 기후완화서비스가 나타났으며, 기후 완화 서비스의 수혜자 인구를 고려한 생태계서비스 평가에서는 수혜인구의 밀도가 높은 서울 도심지역에서 높은 서비스가 나타났다. 기후변화에 따른 산림 생장량 변화를 반영하여 산림의 기후완화 생태계서비스의 변화를 평가한 결과, 평균적으로 약 33%의 서비스 감소가 나타났다. 본 연구의 결과는 도시림을 관리하기 위해서 산림청에서 제시하고 있는 공급기능기반의 6가지(자연환경보전, 산지재해방지, 목재생산, 산림휴양, 생활환경보전, 수원함양) 기능구분 외에 서비스를 수혜하는 수요자 기반의 기능 및 서비스가 평가의 필요성을 제시한다. 이는 기존의 산림의 공급기능기반의 평가에서 간과할 수 있는, 자연기능은 낮지만 수혜를 받는 시민들이 많아 높은 서비스 가치를 갖는 산림을 재평가하고 올바른 관리 계획을 수립하는데 기여할 수 있을 것으로 판단된다.

• 무역상무연구
• /
• 제19권
• /
• pp.224-242
• /
• 2003

The author believes that the main task of study in international trade usage and practice is the management of transactional risks involved in international sale of goods. They are foreign exchange risks, transportation risks, credit risk, risk of miscommunication, etc. In most cases, these risks are more serious and enormous than those involved in domestic sales. Historically, the merchant adventurers organized the voyage abroad, secured trade finance, and went around the ocean with their own or consigned cargo until around the $mid-19^{th}$ century. They did business faceto-face at the trade fair or the open port where they maintained the local offices, so-called "Trading House"(商館). Thererfore, the transactional risks might have been one-sided either with the seller or the buyer. The bottomry seemed a typical arrangement for risk sharing among the interested parties to the adventure. In this way, such organizational arrangements coped with or bore the transactional risks. With the advent of ocean liner services and wireless communication across the national border in the $19^{th}$ century, the business of merchant adventurers developed toward the clear division of labor; sales by mercantile agents, and ocean transportation by the steam ship companies. The international banking helped the process to be accelerated. Then, bills of lading backed up by the statute made it possible to conduct documentary sales with a foreign partner in different country. Thus, FOB terms including ocean freight and CIF terms emerged gradually as standard trade terms in which transactional risks were allocated through negotiation between the seller and the buyer located in different countries. Both of them did not have to go abroad with their cargo. Instead, documentation in compliance with the terms of the contract(plus an L/C in some cases) must by 'strictly' fulfilled. In other words, the set of contractual documents must be tendered in advance of the arrival of the goods at port of discharge. Trust or reliance is placed on such contractual paper documents. However, the container transport services introduced as international intermodal transport since the late 1960s frequently caused the earlier arrival of the goods at the destination before the presentation of the set of paper documents, which may take 5 to 10% of the amount of transaction. In addition, the size of the container vessel required the speedy transport documentation before sailing from the port of loading. In these circumstances, computerized processing of transport related documents became essential for inexpensive transaction cost and uninterrupted distribution of the goods. Such computerization does not stop at the phase of transportation but extends to cover the whole process of international trade, transforming the documentary sales into less-paper trade and further into paperless trade, i.e., EDI or E-Commerce. Now we face the other side of the coin, which is data security and paperless transfer of legal rights and obligations. Unfortunately, these issues are not effectively covered by a set of contracts only. Obviously, EDI or E-Commerce is based on the common business process and harmonized system of various data codes as well as the standard message formats. This essential feature of E-Commerce needs effective coordination of different divisions of business and tight control over credit arrangements in addition to the standard contract of sales. In a few word, information does not alway invite "trust". Credit flows from people, or close organizational tie-ups. It is our common understanding that, without well-orchestrated organizational arrangements made by leading companies, E-Commerce does not work well for paperless trade. With such arrangements well in place, participating E-business members do not need to seriously care for credit risk. Finally, it is also clear that E-International Commerce must be linked up with a set of government EDIs such as NACCS, Port EDI, JETRAS, etc, in Japan. Therefore, there is still a long way before us to go for E-Commerce in practice, not on the top of information manager's desk.

• Weed & Turfgrass Science
• /
• 제7권1호
• /
• pp.1-14
• /
• 2018

우리나라 논, 밭, 과수원 및 목초지에 발생하는 외래잡초를 전국 9개도 12,568지점에서 2013년부터 2015년까지 조사하였다. 논에서는 4과 7종, 밭에서는 24과 130종, 과수원에서는 24과 126종, 목초지는 23과 82종이 조사되었고, 총 28과 166종이 발생하고 있었다. 생활형으로 보면, 일년생은 128종, 다년생 38종이었으며, 동계잡초가 37.9%로, 외래잡초 중 동계잡초의 비율이 상대적으로 높음을 확인할 수 있었다. 유입시기별로 분석한 결과, 1기(1876-1921)에 46종, 2기(1922-1963)에는 16종, 3기(1964-2015)에는 104종이었다. 2기 및 3기 외래잡초의 경우, 생태계교란종도 포함하고 있었으며, 이에 대한 방제 연구가 필요할 것으로 사료된다. 그러나 1기 외래잡초는 귀화잡초로 분류하고, 자생잡초와 같이 분류하는 것이 농경지 잡초관리 계획 수립에 효율적일 것이다. 특히 개쑥갓 등과 같은 외래잡초로 인한 작물의 피해가 점차 증가할 것으로 예상된다. 따라서 각 초종에 대해 생리 생태와 같은 기초연구부터 방제 연구까지 체계적인 연구와 이의 활용이 필요할 것이다.

• Journal of Chest Surgery
• /
• 제40권7호
• /
• pp.480-484
• /
• 2007

서론: 주요 혈관 손상 시 적절한 진단 및 치료가 지연될 경우 환자가 생명을 잃거나 사지를 절단해야 할 위험이 있게 된다. 이러한 혈관 손상의 적절한 치료를 위한 지침을 세워보고자 본원에서 치료한 증례를 분석하였다. 대상 및 방법: 1999년 5월부터 2004년 9월까지 치료받은 외상성 혈관 손상 환자 26명을 대상으로 연령 및 성별 분포, 혈관 손상의 위치, 원인, 진단방법, 혈관 손상의 형태, 임상소견, 치료방법, 합병증 등을 살펴보았다. 결과: 환자의 연령분포는 평균 39.5세($12{\sim}86$세)였고 손상입은 혈관은 하행대동맥 6예, 대퇴 동맥 4예, 슬와 정맥 4예 등의 순으로 빈번하게 발생하였다. 손상의 원인으로는 의인성 손상이 8예로 가장 많았고 그 다음이 교통사고 7예, 자상 6예, 산업재해 5예 순이었다. 진단방법은 CT와 Arteriogram이 각각 9예씩으로 가장 많았고 수술 중에 발생한 의인성인 경우는 이학적 검사만으로도 진단이 가능하였다. 혈관손상의 형태는 동맥인 경우 가성 동맥류가 10예로 가장 많았고. 부분 절단된 경우가 5예, 완전 절단된 경우가 3예, 폐색이 3예 등이었다. 정맥손상의 경우는 부분절단이 6예, 완전 절단이 2예였고 동정맥루의 형태가 2예 등이었다. 임상 소견은 맥박손실 8예, 냉감 1예, 흉통 6예, 부종 5예, 출혈 5예 등이었다. 치료는 동맥손상인 경우 Graft interposition이 11예로 가장 많았고 primary repair가 4예, 단단 문합이 2예였고 동정맥루 2예는 모두 중재적 시술(endovascular repair)을 시행하였다. 심각한 합병증으로는 지연된 진단 및 치료로 인한 지체 소실이 3예 있었고 3예에서 동반된 신경손상으로 인한 운동장애 그리고 1예에서 다발성 장기 부전으로 사망하였다. 결론: 사지 보존율을 높이고 사망률을 줄이기 위해서는 즉각적인 진단과 치료를 시행할 수 있는 시스템 확보가 필수적이다. 또한 중재적 시술이 증가하는 요즘 경향을 볼 때 발생의 예방을 위한 의사 교육이 중요하며 발생 시 즉각적으로 혈관 외과의사가 개입할 수 있도록 원활한 의사 교환 및 협진 체제가 중요하다고 하겠다.

• 한국보건간호학회지
• /
• 제6권1호
• /
• pp.32-45
• /
• 1992

An important role of community health nurses in health centers is to solve community health problems found through data collection methodology which has been used to identify the health needs of the community, diagnose the health problems and to plan health programs suitable for the health problems. Also community health nurses must be prepared to know the community health needs and to participate in the planning process. Since 1956 when the health center law was established, community health nurses have really implemented only the services which the government has asked them to do. This has kept them busy enough. But these days as society is in rapid change, community health nurses should have the flexibility to deal with the social change and demands that are unique to their community each which has different health needs and demands. So community health nurses need to identify what community health problems exist in their particular communities. The purposes of this study were as follows. 1) To explore the suitability of the health programs which the government has asked the community health nurses to do for their own communities and if these programs are not suitable, to explore the reasons why. 2) To explore the degree to which the community health nurses have the ability to identify health problems in their own communities and activate the community diagnostic process. 3) To identify the degree that the community health nurses have the ability to implement plans related to community diagnosis. 4) To find out how much data related to community health problems, the community health nurses have and how they are utilizing it. 5) To measure the community health nurses self-confidence concerning diagnostic activities for community health. The study subjects were 454 Community Health Nurses working in Health Centers in Seoul, Korea. The period of data collection was 6 days(Nov. 9th 1991-Nov. 15th 1991). A questionnaire used for data collection was composed of three different items; general characteristics, community health diagnostic activities and self-confidence in performing diagnostic activities. The results of the study are as follows. First, over one third of the respondents replied that the government required activities for their communities are not appropriate. Of these activities the most frequent reply $(51.2\%)$ indicated that many of the activities in the community were inappropriate to the actual situation. Further, $25\%$ of the replies indicated that many activities were only administratively oriented and as such not appropriate. Second, $49.8\%$ of the respondents replied that they had done general assessments and had a general idea of the health problems of their community. Effective solutions to health problems could be found with an increase in health personnel and management ability according to $41.5\%$ of the respondents. Third, to the question as to whether they had ever independently implemented a plan towards solving community diagnosed problems, $52\%$ of nurses replied 'never', $40\%$ 'occasionally' but only $7.5\%$ replied that they did it frequently. Actually there was very little done even in the basic work of collecting the necessary data. Fourth, when asked how much of basic information they had collected that might be used in community diagnosis activity, of 26 items in 5 areas, there was hardly one for which complete data had been collected. Fifteen percent did have data on the geographical aspects of their area, housing distribution and types of housing, while $17.8\%$ knew the frequency with which the health center was used. Concerning community resources, even with a list of community resources, only $12.3\%$ had data on any of these resources, and this data was incomplete. Further, information about social work institutions, and facilities was also incomplete, only $14.2\%$ of the respondents had any data and even it was incomplete; that is, in general, the nurses did not have this information. Fifth, concerning the confidence of the community health nurse in their ability to carry out community diagnoses activities, $60\%$ replied that they were very or at least nominally confident, indicating that although they were not doing community diagnostic activities they felt they could do so, as they were carrying out home visits and program planning as part of their official duties. The following recommendations are made based on the results of this study. First; since the community health nurses have a high perception of the need for community diagnostic activities and. high confidence in their ability to carry out this activity and high percentage of respondents replied that with a little training they could do this even better it is recommended that community diagnostic activity training be included in the continuing education program for community health nurses. Second, in order for the Community Health Nurses to successfully solve the health problems of their respective community they reported to a need to increase the number of health personnel, improve the facilities and the system of managing their work. Considering this, it is recommended that ways be sought to remedy these deficits.

• 생태와환경
• /
• 제46권4호
• /
• pp.488-498
• /
• 2013

본 연구에서는 상류 댐 및 유입 지류의 물리적, 지형적 특성을 고려하여 의암호 수체의 혼합 거동을 해석하고 수질 분포에 미치는 인자로 수체간 혼합 과정을 파악하기 위하여 3차원 시변화 모델, GEMSS 모델 시스템을 구축하였다. 실측 자료를 바탕으로 적용 모델의 재현성을 검토한 결과 본 연구에서 적용된 GLLVHT 모델은 상이한 강우 및 유량 조건에서 의암호 내 열수지 및 수체 혼합 특성을 잘 재현하고 있는 것으로 판단되었으며, 모델 보정 결과를 바탕으로 의암호의 수온, 전기전도도 그리고 체류시간의 시 공간적 분포와 유입지류의 흐름 특성을 분석하였다. 의암호는 상이한 목적을 가진 소양강댐과 춘천댐의 방류량과 유입 지류의 큰 변동폭에 수리 및 수질이 영향을 많이 받고 있다. 의암호는 봄과 여름철에는 수온이 높은 춘천댐의 방류량에 상대적으로 영향을 크게 받아, 전체적으로 높은 수온 분포를 나타낸다. 반면 가을과 겨울철에는 소양강댐의 방류 유량이 많고 수온이 높고, 춘천댐의 유량이 매우 적어 상대적으로 전기전도도가 낮은 소양강댐 방류수의 수온이 의암호의 온도 분포에 영향을 미치는 것으로 분석되었다. 전기전도도는 춘천하수처리장과 공지천의 높은 유입으로 하류 의암댐 부근까지 높은 전기전도도의 분포를 나타낸다. 의암호의 체류시간은 춘천댐과 소양강댐의 방류수가 유입되는 상류 수역은 체류시간이 비교적 짧게 나타나며 의암댐 부근의 하류에서 점차 증가하는 것으로 분석되었다. 중도 부근의 낮은 수심으로 인해 소양강댐 방류량이 많은 시기에는 역류현상이 발생하여 체류시간이 일시적으로 증가한다. 또한 하중도의 우안에서 공지천과 춘천하수처리장이 유입되는 수역, 중도의 우안에서는 연중 20일 이상의 체류시간을 보이고 있다. 이러한 정체수역에서는 지류들의 혼합률이 저하되고 유속이 낮은 특징을 가지기 때문에, 식물성 플랑크톤의 과대성장 우려가 있어 수질관리에 신중을 기해야 할 것으로 판단된다. 여름철 집중 강우시에는 유입 및 유출의 급격한 증가로 체류시간은 크게 감소하며, 춘천댐과 소양강댐의 방류수는 약 10일 이하의 짧은 체류시간으로 의암호로 유입되는 것으로 예측되었다. 의암호 내 표층에서는 소양강댐의 방류가 많은 비중을 차지하며, 특히 중도의 우안의 상류부까지 소양강댐의 방류수가 역류하는 현상이 나타나며, 중도의 좌안과 붕어섬 상류부에서 소양강댐 방류수가 흐르는 것을 알 수 있다. 춘천댐의 방류량이 큰 경우에는 소양강댐의 방류수가 중도 좌안에 거의 영향을 주지 않으며 우안을 따라서 그대로 방류되는 특징을 보인다. 또한 붕어섬 상류부를 통하여 춘천댐의 방류수가 중도 좌안 및 소양강댐 방류 합류지점까지 영향을 미치는 것을 알 수 있다. 공지천의 방류수는 소양강댐의 방류수가 많은 시기에 동시에 증가하여 공지천과 의암호 합류부의 상류로 역류하는 현상을 보이고 있다.

• Radiation Oncology Journal
• /
• 제6권1호
• /
• pp.63-73
• /
• 1988

One hundred fifty-four patients with the carcinoma of the uterine cervix were studied retrospectively to assess the result and impact of treatment at Department of Radiation Oncology, Korea University, Hae-Wha Hospital from Feb 1981 through Dec. 1986. Prior to radiotherapy, the patients were evaluated and staged by recommendation of FIGO including physical examination, pelvic examination, cystoscopy, rectosigmoidoscopy, chest X-ray, IVP. Ba enema. Also, an additional pelvic CT scan was obtained for some of the patients. The patients were treated by radiotherapy alone or adjuvant postoperative irradiation; in case of radiation therapy only, whole pelvic irradiation was given with Co-60 teletherapy unit via AP and PA parallel opposing fields or 4-oblique fields, 180 cGy per day, 5 days per week and intracavitary insertion was performed. In satges Ia, Ib, and IIa with small primary lesion, external irradiation was initially given to pelvis up to $2,000\~3,000\;cGy/2frac{1}{2}\;-3frac{1}{2}$ weeks and then intracavitary insertion was performed using Fletcher-Mini-Declos Applicator with cesium-137 cources and followed by external irradiation of $1,000\~2,000\;cGy/1frac{1}{2}\;-2frac{1}{2}$weeks via AP and PA parallel opposing fields with midline shield to spare of bladder and rectum. However, if the primary lesion is large, external irradiation was given without midline shield. More than stages IIb, the patients were treated by external beam irradiation up to 5,400cGy/30f for 6 weeks via 4-oblique portals and at the dose of 5,040cGy/28f the field was cut 5cm from the top margin for spare of small bowel, and followed by intracavitary irradiation, If there was residual tumor an additional dose of $900\~l,200cGy/5\~7f$ was given to parametrium and/or residual tumor area. Total dose of radiation to A and B-point were as follows; A-point; In early stages, Ia, Ib, IIa; $8,000\~9,000$ B-point $5,000\~6,000 cGy$ A-point; In advanced stages IIb, IIIa, IIIb; $9,000\~10,000$ B-point $60,000\~7,000cGy$ The results were obtained and as fellows; 1 The patients distribution according to FIGO staging system were stage Ia 6, Ib 27, IIa 28, IIb 54, IIIa 12, IIIb 18, and stage IVa 9. 2. Value of CT scan were demonstration of cervix tumor mass, parametrial and pelvic side wall tumor spread, pelvic and inguinal lymph nodes metastases, and hydronephrosis. Three dimensional quantitative demonstration of tumor volume is also important in planning radiation therapy. Another advantage of CT scan was detection of recurrent tumor after radiation or surgery. 3. Local control rate of tumor according to the size was $91.3\%$ for less than 5cm in size and $44.6\%$ in tumor over 5cm (p<0.0068). 4. Thirty out of 50 recurrent sites has locoregional failures and 17 cases has distant metastases. And the para-aortic lymph nodes were the most common site for distant metastases. 5. The most common complication was temporal rectal bleeding which was controlled most by conservative management. However, 4 patients required for endoscopic cauterization. 6. The 5-year survival rates showed; stage la and Ib $95\%,\;stage\;IIa\;81\%\;stage\;lIb\;67\%,\;stage\;IIIa\;37.7\%,\;stage\;IIIb\;23\%$ and 3-year survival rate of stage IVa showed $11.6%$, retrospectively.

• 한국균학회소식:학술대회논문집
• /
• 한국균학회 2018년도 춘계학술대회 및 임시총회
• /
• pp.27-27
• /
• 2018

The production scale of mushroom cultivation in Korea is approximately 600 billion won, which is 1.6% of the Korean gross agricultural output. Annually, ca. 190,000 tons of mushrooms are harvested in Korea. Although the numbers of mushroom farms and cultivators are constantly decreasing, the total mushroom yields are increasing due to the large-scale cultivation facilities and automation. The recent expansion of the well-being trend causes increase in mushroom consumption in Korea: annual per capita consumption of mushroom was 3.9kg ('13) that is a little higher than European's average. Thus the exports of mushrooms, mainly Flammulina velutipes and Pleurotus ostreatus, have been increased since the middle of 2000s. Recently, however, it is slightly reduced. However, Vietnam, Hong Kong, the United States, the Netherlands and continued to export, and the country has increased recently been exported to Australia, Canada, Southeast Asia and so on. Canned foods of Agaricus bisporus was the first exports of the Korean mushroom industry. This business has reached the peak of the sale in 1977-1978. As Korea initiated trade with China in 1980, the international prices of mushrooms were sharply fall that led to shrink the domestic markets. According to the high demand to develop new items to substitute for A. bisporus, oyster mushroom (Pleurotus ostreatus) was received the attention since it seems to suit the taste of Korean consumers. Although log cultivation technique was developed in the early 1970s for oyster mushroom, this method requires a great deal of labor. Thus we developed shelf cultivation technique which is easier to manage and allows the mass production. In this technique, the growing shelf is manly made from fermented rice straw, that is the unique P. ostreatus medium in the world, was used only in South Korea. After then, the use of cotton wastes as an additional material of medium, the productivity. Currently it is developing a standard cultivation techniques and environmental control system that can stably produce mushrooms throughout the year. The increase of oyster mushroom production may activate the domestic market and contribute to the industrial development. In addition, oyster mushroom production technology has a role in forming the basis of the development of bottle cultivation. Developed mushroom cultivation technology using bottles made possible the mass production. In particular, bottle cultivation method using a liquid spawn can be an opportunity to export the F.velutipes and P.eryngii. In addition, the white varieties of F.velutipes were second developed in the world after Japan. We also developed the new A.bisporus cultivar "Sae-ah" that is easy to grown in Korea. To lead the mushroom industry, we will continue to develop the cultivars with an international competitive power and to improve the cultivation techniques. Mushroom research in Korea nowadays focuses on analysis of mushroom genetics in combination with development of new mushroom varieties, mushroom physiology and cultivation. Further studied are environmental factors for cultivation, disease control, development and utilization of mushroom substrate resources, post-harvest management and improvement of marketable traits. Finally, the RDA manages the collection, classification, identification and preservation of mushroom resources. To keep up with the increasing application of biotechnology in agricultural research the genome project of various mushrooms and the draft of the genetic map has just been completed. A broad range of future studies based on this project is anticipated. The mushroom industry in Korea continually grows and its productivity rapidly increases through the development of new mushrooms cultivars and automated plastic bottle cultivation. Consumption of medicinal mushrooms like Ganoderma lucidum and Phellinus linteus is also increasing strongly. Recently, business of edible and medicinal mushrooms was suffering under over-production and problems in distribution. Fortunately, expansion of the mushroom export helped ease the negative effects for the mushroom industry.

• Asia pacific journal of information systems
• /
• 제20권1호
• /
• pp.127-140
• /
• 2010

The benefit that a consumer derives from the use of a good often depends on the number of other consumers purchasing the same goods or other compatible items. This property, which is known as network externality, is significant in many IT related industries. Over the past few decades, network externalities have been recognized in the context of physical networks such as the telephone and railroad industries. Today, as many products are provided as a form of system that consists of compatible components, the appreciation of network externality is becoming increasingly important. Network externalities have been extensively studied among economists who have been seeking to explain new phenomena resulting from rapid advancements in ICT (Information and Communication Technology). As a result of these efforts, a new body of theories for 'New Economy' has been proposed. The theoretical bottom-line argument of such theories is that technologies subject to network effects exhibit multiple equilibriums and will finally lock into a monopoly with one standard cornering the entire market. They emphasize that such "tippiness" is a typical characteristic in such networked markets, describing that multiple incompatible technologies rarely coexist and that the switch to a single, leading standard occurs suddenly. Moreover, it is argued that this standardization process is path dependent, and the ultimate outcome is unpredictable. With incomplete information about other actors' preferences, there can be excess inertia, as consumers only moderately favor the change, and hence are themselves insufficiently motivated to start the bandwagon rolling, but would get on it once it did start to roll. This startup problem can prevent the adoption of any standard at all, even if it is preferred by everyone. Conversely, excess momentum is another possible outcome, for example, if a sponsoring firm uses low prices during early periods of diffusion. The aim of this paper is to analyze the dynamics of the adoption process in markets exhibiting network effects by focusing on two factors; switching and agent heterogeneity. Switching is an important factor that should be considered in analyzing the adoption process. An agent's switching invokes switching by other adopters, which brings about a positive feedback process that can significantly complicate the adoption process. Agent heterogeneity also plays a important role in shaping the early development of the adoption process, which has a significant impact on the later development of the process. The effects of these two factors are analyzed by developing an agent-based simulation model. ABM is a computer-based simulation methodology that can offer many advantages over traditional analytical approaches. The model is designed such that agents have diverse preferences regarding technology and are allowed to switch their previous choice. The simulation results showed that the adoption processes in a market exhibiting networks effects are significantly affected by the distribution of agents and the occurrence of switching. In particular, it is found that both weak heterogeneity and strong network effects cause agents to start to switch early and this plays a role of expediting the emergence of 'lock-in.' When network effects are strong, agents are easily affected by changes in early market shares. This causes agents to switch earlier and in turn speeds up the market's tipping. The same effect is found in the case of highly homogeneous agents. When agents are highly homogeneous, the market starts to tip toward one technology rapidly, and its choice is not always consistent with the populations' initial inclination. Increased volatility and faster lock-in increase the possibility that the market will reach an unexpected outcome. The primary contribution of this study is the elucidation of the role of parameters characterizing the market in the development of the lock-in process, and identification of conditions where such unexpected outcomes happen.