Termites are important decomposers in the ecosystem. They are also economically significant structural pests. In this study, we reviewed the developments of termite control and recent research on termite management to provide information on the prevention and control of termites. In Korea, most of the damage to wooden historical buildings is caused by subterranean termites. Reticulitermes speratus kyushuensis is the main species, which is widely found throughout the country. In the early 1900s, inorganic insecticides, such as arsenic dust, were used for termite control. After the synthesis of chlorinated hydrocarbon pesticide in the 1940s, it was widely utilized and demonstrated high termite control efficacy. However, chlorinated hydrocarbon insecticides were later banned, disappearing from markets after reports emerged concerning environmental contamination and toxicity to humans. Therefore, the termite control industry sought a new termiticide; hence many pesticides were utilized for termite control. Organophosphate (1960s), carbamate (1970s), pyrethroid, and insect growth inhibitor (1980s) were newly synthesized and adopted. In the 1990s, the first commercial baits using chitin synthesis inhibitors (CSI) were developed, providing a means to eliminate an entire colony of subterranean termites around a structure. Many studies have been carried out on soil termiticides (liquid termiticides) and CSI baits to increase their efficacy, and different baits such as aboveground bait stations, fluid bait, and high-durability bait were also developed in the 2000s. In addition, the paradigm of termite control has shifted from localized treatments using soil termiticides to area-wide pest management using CSI baits to create termite-free zones and protect buildings over time. Termite infestations in wooden historical buildings in Korea have been reported since 1980, and considerable attention was drawn in the 1990s when several UNESCO world heritages such as the Jongmyo Shrine and the Janggyeong Panjeon Depositories of Haeinsa Temple were infested by subterranean termites. Since then, a survey of termite infestation in wooden architectural heritage has been conducted, and the National Research Institute of Cultural Heritage and Heritage Care Program regularly monitors those properties. Finally, we suggest termite management using primarily CSI baits, selective application of various soil treatments applied to the object, foundation soil treatment, research and development of durable termite baits, application of area-wide programs for wooden-building complexes, application of integrated termite management (ITM), and regular education for owners and managers to prevent and reduce termite damage.
As Asia's leading advanced country, Korea has an absolute advantage over foreign trade routes and maritime economies over inland countries. Following the change in social background, the original port area is for various reasons, and some ills are gradually revealing people's private interests. Due to this, it is the economic interest and future development space of the marine industry cluster in the port area that are directly affected and damaged. This study studied the relationship between marine industry clusters and port urban regeneration. It is intended to present the necessity and importance of activating the marine industry cluster through port urban regeneration while analyzing the regenerative design from the quantitative analysis angle. Therefore, first of all, the theoretical backgrounds were considered, and the cases of port cities that did well worldwide were analyzed according to the current status of the northern port of Busan, the research target site, through analysis. In addition, in order to increase the reliability of this study, the data of marine industry clusters and port city regeneration were reviewed using empirical analysis. Looking at the results of this study's case study and empirical analysis, it is a relationship that actually improved and interacted between the marine industry cluster and the port city regeneration. Through the study, it is expected that the Busan North Port Redevelopment Project will be promoted at the design, environmental, and economic level, and at the same time, it will be able to enhance its status as a marine city in Busan. The results show that, no matter which country or port city, the development of economy, society, culture and will inevitably promote the vigorous development of the marine industrial cluster, also, the port area development to a certain degree. will naturally the physical conditions of regional development obstacle through the port city of regeneration. This promotion will overcome.
Soryeon Park;Sanghun Son;Jaegu Bae;Doi Lee;Dongju Seo;Jinsoo Kim
Korean Journal of Remote Sensing
/
v.39
no.5_1
/
pp.655-667
/
2023
Algal bloom outbreaks are frequently reported around the world, and serious water pollution problems arise every year in Korea. It is necessary to protect the aquatic ecosystem through continuous management and rapid response. Many studies using satellite images are being conducted to estimate the concentration of chlorophyll-a (Chl-a), an indicator of algal bloom occurrence. However, machine learning models have recently been used because it is difficult to accurately calculate Chl-a due to the spectral characteristics and atmospheric correction errors that change depending on the water system. It is necessary to consider the factors affecting algal bloom as well as the satellite spectral index. Therefore, this study constructed a dataset by considering water quality, hydrological and meteorological factors, and sentinel-2 images in combination. Representative ensemble models random forest and extreme gradient boosting (XGBoost) were used to predict the concentration of Chl-a in eight weirs located on the Nakdong river over the past five years. R-squared score (R2), root mean square errors (RMSE), and mean absolute errors (MAE) were used as model evaluation indicators, and it was confirmed that R2 of XGBoost was 0.80, RMSE was 6.612, and MAE was 4.457. Shapley additive expansion analysis showed that water quality factors, suspended solids, biochemical oxygen demand, dissolved oxygen, and the band ratio using red edge bands were of high importance in both models. Various input data were confirmed to help improve model performance, and it seems that it can be applied to domestic and international algal bloom detection.
Journal of the Korea institute for structural maintenance and inspection
/
v.27
no.6
/
pp.152-161
/
2023
In general, large-capacity hydrogen storage vessels, typically in the form of vertical cylindrical vessels, are constructed using steel materials. These vessels are anchored to foundation slabs that are specially designed to suit the environmental conditions. This anchoring method involves pre-installed anchors on top of the concrete foundation slab. However, it's important to note that such a design can result in concentrated stresses at the anchoring points when external forces, such as seismic events, are at play. This may lead to potential structural damage due to anchor and concrete damage. For this reason, in this study, it selected an vertical hydrogen storage vessel based on site observations and created a 3D finite element model. Artificial seismic motions made following the procedures specified in ICC-ES AC 156, as well as domestic recorded earthquakes with a magnitude greater than 5.0, were applied to analyze the structural behavior and performance of the target structures. Conducting experiments on a structure built to actual scale would be ideal, but due to practical constraints, it proved challenging to execute. Therefore, it opted for an analytical approach to assess the safety of the target structure. Regarding the structural response characteristics, the acceleration induced by seismic motion was observed to amplify by approximately ten times compared to the input seismic motions. Additionally, there was a tendency for a decrease in amplification as the response acceleration was transmitted to the point where the centre of gravity is located. For the vulnerable components, specifically the sub-system (support columns and anchorages), the stress levels were found to satisfy the allowable stress criteria. However, the concrete's tensile strength exhibited only about a 5% margin of safety compared to the allowable stress. This indicates the need for mitigation strategies in addressing these concerns. Based on the research findings presented in this paper, it is anticipated that predictable load information for the design of storage vessels required for future shaking table tests will be provided.
This research was performed to investigate the morphological changes of folliculus ovary according to the radiation dose. The whole body radiation of 200 cGy, 400 cGy, and 600 cGy was given to the each groups of 5 months-aged female mouse. Various staining methods used in this research are: Hematosylin-Eosin method, and immunohistochemistrical methods using BrdU, TUNEL, p53, p21, PCNA and inhibin. The minute structural changes of folliculus ovary were observed through an electron microscope with high magnification. The morphological changes of growing folliculus ovary became distinct as the dose of X-rays increased. Especially, the nuclei of granular cells showed manifest condensation and the changes of the transparent zone were distinct. As a result of histochemical reaction according to Masson's trichrome method and reticular fiber method, the changed granular cells, the deformed basilar membrane of folliculus ovary and the abnormal arrangement of the reticular fiber were observed. In the reaction of BrdU, the granular cells of normal folliculus ovary with positive reaction rapidly decreased according to the increase of the dose of X-rays. In TUNEL study, granular cells showing positive reaction in retarded folliculus ovary were expanded to growing folliculus ovary and primordial folliculus ovary according to the increase of the dose of X-rays. In case of 600 cGy of X-rays, oocyte underwent apoptosis. In p53 immunohistochemistry, p53 manifested to be stronger as the dose of X-rays increased. p53 reactivity was manifested distinctively in all cells comprising folliculus ovary following irradiation of 600 cGy. p21 was manifested in granular cells of folliculus ovary and showed very positive reaction around follicular antrum according to the increase of the dose of X-rays. In PCNA, positive reaction was manifested in growing folliculus ovary, mature folliculus ovary and primordial folliculus ovary, but the extent of the reaction decreased as the dose of the X-rays decreased. The finding that the reaction of granular cells around folliculus ovary was stronger than that near follicular membrane indicates that what was damaged first by X-ray was the cells near folliculus ovary and follicular antrum. The reactivity of $inhibin-{\alpha}$ showed difference according to the growing stage of folliculus ovary: $inhibin-{\alpha}$ showed the most strong reaction in mature folliculus ovary with follicular antrum. There was strong reaction in granular cells around follicular membrane but $inhibin-{\alpha}$ did not occur at all in theca cells comprising follicular membrane. $Inhibin-{\alpha}$ in ovary tissue exposed to 400 cGy of X-rays was manifested more strongly than in ovary tissue exposed to 600 cGy of X-rays, which was related to the phenomenon that granular cells of mature folliculus ovary underwent necrosis or apoptosis increasingly due to X-rays. In an electron microscope with high magnification, nuclei and protoplasm of granular cells in growing folliculus ovary abruptly underwent minute structural changes according to the increase of dose of X-rays. Cell residue, by-product of cell decease, neutrophil and macrophage around follicular antrum were observed. The minute structural changes in granular cells showed typical characteristics of apoptosis: the increase of electronic density due to nuclear condensation, fragmentation of nuclei and atrophy of protoplasm. Necrosis of cells was identified but it was not so remarkable. Macrophage with apoptotic bodies was scattered. Proportional to the radiation dose, we found that the generation of heterogeneous substance of normal ovary texture's follicular fluid, the emergence of dyeing characteristic in the basilar membrane of folicle, the generation of apoptosis, and the transformation of macrophages, etc. From this results, we can infer the possible radiation hazard on the ovary of cervix cancer patient with radiation therapy.
Kim Kee-Hyuk;Kim Sang-Yun;Kang Yong-Joo;Maeng Won-Jae;Kim Kyo-Sun
Childhood Kidney Diseases
/
v.3
no.2
/
pp.170-179
/
1999
Purpose: To evaluate whether or not sodium restriction had its own beneficial effect and increased the efficiency of the anti-hypertensive drugs on the progression of renal failure. Methods: We studied using the excision remnant kidney model. Treatment groups were as follows: 5/6 nephrectomy and a 0.49% (normal-high) sodium diet (NN); 5/6 nephrectomy and a 0.25% (normal-low) sodium diet (LN); 5/6 nephrectomy, a 0.49% sodium diet and enalapril (NNE); 5/6 nephrectomy, a 0.49% sodium diet and nicardipine (NNN); 5/6 nephrectomy, a 0.25% sodium diet and enalapril (LNE); 5/6 nephrectomy, a 0.25% sodium diet and nicardipine (LNN). Both diets were isocaloric and had the same content of protein, phosphorus and calcium. Proteinuria, remnant kidney weight, mesangial expansion scores, and glomerular volume were assessed. Results: Blood pressure tended to be lower in LN compared to NN (P<0.05). NN developed progressive hypertension. LNE, LU, NNE, and NNN reduced blood pressure. LNE, LNN, NNE, NNN, and LN had significantly less proteinuria than NN at 16 weeks (P<0.05). At 24 weeks, LN developed proteinuria (82 mg/day), which were lessened in LNE (54 mg/day) and not lessened in LNN (76 mg/day). Mesangial expansion scores were significantly less in LN rats compared to those in NN rats. Glomerular volumes at 24 weeks in LN rats were significantly less compared to those at 16 weeks in NN rats. Mesangial expansion scores and glomerular volumes at 4, weeks, 12 weeks, and 24 weeks were not different among LN, LNE, and LNN groups. Conclusion: Dietary salt restriction lessens renal damage, at least in part, by inhibiting compensatory renal growth and reducing blood pressure. Enalapril was particularly successful in reducing proteinuria and glomerular injury when combined with dietary salt restriction.
Lee Sub;Ko Mgo-Sung;Park Ki-Sung;Ryu Jae-Kean;Jang Jae-Suk;Kwon Oh-Choon
Journal of Chest Surgery
/
v.39
no.5
s.262
/
pp.359-365
/
2006
Background: Arterial grafts have been used to achieve better long-term results for coronary revascularization. Bilateral internal thoracic artery (ITA) grafts have a better results, but it may be not used in some situations such as diabetes and chronic obstructive pulmonary disease (COPD). We evaluated the clinical and angiographic results of composite left internal thoracic artery-radial artery (LITA-RA) Y graft. Material and Method: Between April 2002 and September 2004, 119 patients were enrolled in composite Y graft for coronary bypass surgery. The mean age was $62.6{\pm}8.8$ years old and female was 34.5%. Preoperative cardiac risk factors were as follows: hypertension 43.7%, diabetes 33.6%, smoker 41.2%, and hyperlipidemia 22.7%, There were emergency operation (14), cardiogenic shock (6), left ventricle ejection fraction (LVEF) less than 40% (17), and 17 cases of left main disease. Coronary angiography was done in 35 patients before the hospital discharge. Result: The number of distal anastomoses was $3.1{\pm}0.91$ and three patients (2.52%) died during hospital stay. The off-pump coronary artery bypass (OPCAB) was applied to 79 patients (66.4%). The LITA was anastomosed to left anterior descending system except three cases which was to lateral wall. The radial Y grafts were anastomosed to diagonal branches (4), ramus intermedius (21), obtuse marginal branches (109), posterolateral branches (12), and posterior descending coronary artery (8). Postoperative coronary angiography in 35 patients showed excellent patency rates (LITA 100%, and RA 88.5%; 3 RA grafts which anastomosed to coronary arteries <70% stenosed showed string sign with competitive flow). Conclusion: The LITA-RA Y composite graft provided good early clinical and angiographic results in multivessel coronary revascularization. But it should be cautiously used in selected patients.
Today, the rapid advance of scientific technologies has brought about fundamental changes to the types and levels of terrorism while the war against the world more than one thousand small and big terrorists and crime organizations has already begun. A method highly likely to be employed by terrorist groups that are using 21st Century state of the art technology is cyber terrorism. In many instances, things that you could only imagine in reality could be made possible in the cyber space. An easy example would be to randomly alter a letter in the blood type of a terrorism subject in the health care data system, which could inflict harm to subjects and impact the overturning of the opponent's system or regime. The CIH Virus Crisis which occurred on April 26, 1999 had significant implications in various aspects. A virus program made of just a few lines by Taiwanese college students without any specific objective ended up spreading widely throughout the Internet, causing damage to 30,000 PCs in Korea and over 2 billion won in monetary damages in repairs and data recovery. Despite of such risks of cyber terrorism, a great number of Korean sites are employing loose security measures. In fact, there are many cases where a company with millions of subscribers has very slackened security systems. A nationwide preparation for cyber terrorism is called for. In this context, this research will analyze the current status of Korea's cyber security systems and its laws from a policy perspective, and move on to propose improvement strategies. This research suggests the following solutions. First, the National Cyber Security Management Act should be passed to have its effectiveness as the national cyber security management regulation. With the Act's establishment, a more efficient and proactive response to cyber security management will be made possible within a nationwide cyber security framework, and define its relationship with other related laws. The newly passed National Cyber Security Management Act will eliminate inefficiencies that are caused by functional redundancies dispersed across individual sectors in current legislation. Second, to ensure efficient nationwide cyber security management, national cyber security standards and models should be proposed; while at the same time a national cyber security management organizational structure should be established to implement national cyber security policies at each government-agencies and social-components. The National Cyber Security Center must serve as the comprehensive collection, analysis and processing point for national cyber crisis related information, oversee each government agency, and build collaborative relations with the private sector. Also, national and comprehensive response system in which both the private and public sectors participate should be set up, for advance detection and prevention of cyber crisis risks and for a consolidated and timely response using national resources in times of crisis.
본 웹사이트에 게시된 이메일 주소가 전자우편 수집 프로그램이나
그 밖의 기술적 장치를 이용하여 무단으로 수집되는 것을 거부하며,
이를 위반시 정보통신망법에 의해 형사 처벌됨을 유념하시기 바랍니다.
[게시일 2004년 10월 1일]
이용약관
제 1 장 총칙
제 1 조 (목적)
이 이용약관은 KoreaScience 홈페이지(이하 “당 사이트”)에서 제공하는 인터넷 서비스(이하 '서비스')의 가입조건 및 이용에 관한 제반 사항과 기타 필요한 사항을 구체적으로 규정함을 목적으로 합니다.
제 2 조 (용어의 정의)
① "이용자"라 함은 당 사이트에 접속하여 이 약관에 따라 당 사이트가 제공하는 서비스를 받는 회원 및 비회원을
말합니다.
② "회원"이라 함은 서비스를 이용하기 위하여 당 사이트에 개인정보를 제공하여 아이디(ID)와 비밀번호를 부여
받은 자를 말합니다.
③ "회원 아이디(ID)"라 함은 회원의 식별 및 서비스 이용을 위하여 자신이 선정한 문자 및 숫자의 조합을
말합니다.
④ "비밀번호(패스워드)"라 함은 회원이 자신의 비밀보호를 위하여 선정한 문자 및 숫자의 조합을 말합니다.
제 3 조 (이용약관의 효력 및 변경)
① 이 약관은 당 사이트에 게시하거나 기타의 방법으로 회원에게 공지함으로써 효력이 발생합니다.
② 당 사이트는 이 약관을 개정할 경우에 적용일자 및 개정사유를 명시하여 현행 약관과 함께 당 사이트의
초기화면에 그 적용일자 7일 이전부터 적용일자 전일까지 공지합니다. 다만, 회원에게 불리하게 약관내용을
변경하는 경우에는 최소한 30일 이상의 사전 유예기간을 두고 공지합니다. 이 경우 당 사이트는 개정 전
내용과 개정 후 내용을 명확하게 비교하여 이용자가 알기 쉽도록 표시합니다.
제 4 조(약관 외 준칙)
① 이 약관은 당 사이트가 제공하는 서비스에 관한 이용안내와 함께 적용됩니다.
② 이 약관에 명시되지 아니한 사항은 관계법령의 규정이 적용됩니다.
제 2 장 이용계약의 체결
제 5 조 (이용계약의 성립 등)
① 이용계약은 이용고객이 당 사이트가 정한 약관에 「동의합니다」를 선택하고, 당 사이트가 정한
온라인신청양식을 작성하여 서비스 이용을 신청한 후, 당 사이트가 이를 승낙함으로써 성립합니다.
② 제1항의 승낙은 당 사이트가 제공하는 과학기술정보검색, 맞춤정보, 서지정보 등 다른 서비스의 이용승낙을
포함합니다.
제 6 조 (회원가입)
서비스를 이용하고자 하는 고객은 당 사이트에서 정한 회원가입양식에 개인정보를 기재하여 가입을 하여야 합니다.
제 7 조 (개인정보의 보호 및 사용)
당 사이트는 관계법령이 정하는 바에 따라 회원 등록정보를 포함한 회원의 개인정보를 보호하기 위해 노력합니다. 회원 개인정보의 보호 및 사용에 대해서는 관련법령 및 당 사이트의 개인정보 보호정책이 적용됩니다.
제 8 조 (이용 신청의 승낙과 제한)
① 당 사이트는 제6조의 규정에 의한 이용신청고객에 대하여 서비스 이용을 승낙합니다.
② 당 사이트는 아래사항에 해당하는 경우에 대해서 승낙하지 아니 합니다.
- 이용계약 신청서의 내용을 허위로 기재한 경우
- 기타 규정한 제반사항을 위반하며 신청하는 경우
제 9 조 (회원 ID 부여 및 변경 등)
① 당 사이트는 이용고객에 대하여 약관에 정하는 바에 따라 자신이 선정한 회원 ID를 부여합니다.
② 회원 ID는 원칙적으로 변경이 불가하며 부득이한 사유로 인하여 변경 하고자 하는 경우에는 해당 ID를
해지하고 재가입해야 합니다.
③ 기타 회원 개인정보 관리 및 변경 등에 관한 사항은 서비스별 안내에 정하는 바에 의합니다.
제 3 장 계약 당사자의 의무
제 10 조 (KISTI의 의무)
① 당 사이트는 이용고객이 희망한 서비스 제공 개시일에 특별한 사정이 없는 한 서비스를 이용할 수 있도록
하여야 합니다.
② 당 사이트는 개인정보 보호를 위해 보안시스템을 구축하며 개인정보 보호정책을 공시하고 준수합니다.
③ 당 사이트는 회원으로부터 제기되는 의견이나 불만이 정당하다고 객관적으로 인정될 경우에는 적절한 절차를
거쳐 즉시 처리하여야 합니다. 다만, 즉시 처리가 곤란한 경우는 회원에게 그 사유와 처리일정을 통보하여야
합니다.
제 11 조 (회원의 의무)
① 이용자는 회원가입 신청 또는 회원정보 변경 시 실명으로 모든 사항을 사실에 근거하여 작성하여야 하며,
허위 또는 타인의 정보를 등록할 경우 일체의 권리를 주장할 수 없습니다.
② 당 사이트가 관계법령 및 개인정보 보호정책에 의거하여 그 책임을 지는 경우를 제외하고 회원에게 부여된
ID의 비밀번호 관리소홀, 부정사용에 의하여 발생하는 모든 결과에 대한 책임은 회원에게 있습니다.
③ 회원은 당 사이트 및 제 3자의 지적 재산권을 침해해서는 안 됩니다.
제 4 장 서비스의 이용
제 12 조 (서비스 이용 시간)
① 서비스 이용은 당 사이트의 업무상 또는 기술상 특별한 지장이 없는 한 연중무휴, 1일 24시간 운영을
원칙으로 합니다. 단, 당 사이트는 시스템 정기점검, 증설 및 교체를 위해 당 사이트가 정한 날이나 시간에
서비스를 일시 중단할 수 있으며, 예정되어 있는 작업으로 인한 서비스 일시중단은 당 사이트 홈페이지를
통해 사전에 공지합니다.
② 당 사이트는 서비스를 특정범위로 분할하여 각 범위별로 이용가능시간을 별도로 지정할 수 있습니다. 다만
이 경우 그 내용을 공지합니다.
제 13 조 (홈페이지 저작권)
① NDSL에서 제공하는 모든 저작물의 저작권은 원저작자에게 있으며, KISTI는 복제/배포/전송권을 확보하고
있습니다.
② NDSL에서 제공하는 콘텐츠를 상업적 및 기타 영리목적으로 복제/배포/전송할 경우 사전에 KISTI의 허락을
받아야 합니다.
③ NDSL에서 제공하는 콘텐츠를 보도, 비평, 교육, 연구 등을 위하여 정당한 범위 안에서 공정한 관행에
합치되게 인용할 수 있습니다.
④ NDSL에서 제공하는 콘텐츠를 무단 복제, 전송, 배포 기타 저작권법에 위반되는 방법으로 이용할 경우
저작권법 제136조에 따라 5년 이하의 징역 또는 5천만 원 이하의 벌금에 처해질 수 있습니다.
제 14 조 (유료서비스)
① 당 사이트 및 협력기관이 정한 유료서비스(원문복사 등)는 별도로 정해진 바에 따르며, 변경사항은 시행 전에
당 사이트 홈페이지를 통하여 회원에게 공지합니다.
② 유료서비스를 이용하려는 회원은 정해진 요금체계에 따라 요금을 납부해야 합니다.
제 5 장 계약 해지 및 이용 제한
제 15 조 (계약 해지)
회원이 이용계약을 해지하고자 하는 때에는 [가입해지] 메뉴를 이용해 직접 해지해야 합니다.
제 16 조 (서비스 이용제한)
① 당 사이트는 회원이 서비스 이용내용에 있어서 본 약관 제 11조 내용을 위반하거나, 다음 각 호에 해당하는
경우 서비스 이용을 제한할 수 있습니다.
- 2년 이상 서비스를 이용한 적이 없는 경우
- 기타 정상적인 서비스 운영에 방해가 될 경우
② 상기 이용제한 규정에 따라 서비스를 이용하는 회원에게 서비스 이용에 대하여 별도 공지 없이 서비스 이용의
일시정지, 이용계약 해지 할 수 있습니다.
제 17 조 (전자우편주소 수집 금지)
회원은 전자우편주소 추출기 등을 이용하여 전자우편주소를 수집 또는 제3자에게 제공할 수 없습니다.
제 6 장 손해배상 및 기타사항
제 18 조 (손해배상)
당 사이트는 무료로 제공되는 서비스와 관련하여 회원에게 어떠한 손해가 발생하더라도 당 사이트가 고의 또는 과실로 인한 손해발생을 제외하고는 이에 대하여 책임을 부담하지 아니합니다.
제 19 조 (관할 법원)
서비스 이용으로 발생한 분쟁에 대해 소송이 제기되는 경우 민사 소송법상의 관할 법원에 제기합니다.
[부 칙]
1. (시행일) 이 약관은 2016년 9월 5일부터 적용되며, 종전 약관은 본 약관으로 대체되며, 개정된 약관의 적용일 이전 가입자도 개정된 약관의 적용을 받습니다.