• Information Systems Review
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• v.17 no.2
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• pp.193-218
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• 2015

The purpose of this study is to investigate the effects of closed-type SNS use (i.e., Naver Band) on the perception and behavior of the Korean Army soldiers. In contrast to open-type SNS (e.g., Facebook or Twitter), Naver Band is an online communication service system mostly based on confined offline social network. Therefore, it increases communication between acquaintances who have previously formed relationships. Although the Korean Army recently began to use Naver Band as a method of communication between soldiers, their parents/acquaintance, and Army commanders (or leaders), little research has been done about how this use directly affects army soldiers. Hence, applying the motivation opportunity ability theory of behavior, this study examines how enjoyment (Motivational factor), social ties (Opportunity factor), and social intelligence (Ability factor) affect soldiers' belongingness to their organization and organizational citizenship behavior (OCB). We also hypothesize that army soldiers' belongingness and OCB may enhance their individual performance. Survey results show that enjoyment, social ties, and social intelligence increase army soldiers' belongingness, which leads to OCB. Also, enhanced OCB increases individual performance. However, the effect of enjoyment and social ties on soldiers' OCB is non-significant and soldiers' belongingness does not have influence on individual performance. Theoretical and practical implications are presented.

• Information Systems Review
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• v.15 no.2
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• pp.1-19
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• 2013

Smart working sparked by iPhone3 opens a revolution in smart ways of working at any time, regardless of location and environment. Also, It provide real-time information processing and analysis, rapid decision-making and the productivity of businesses, including through the timely response and the opportunity to increase the efficiency. As a result, every company are developing mobile information systems. But company data is accessed from the outside, it has problems to solve like security, hacking and information leakage. Also, Mobile devices such as smart phones belonging to the privately-owned asset can't be always controlled to archive company security policy. In the meantime, public smart phones owned by company was always applied security policy. But it can't not apply to privately-owned smart phones. Thus, this paper is focused to archive company security policy, but also enable the individual's free to use of smart phones when we use mobile information systems. So, when we use smart phone as individual purpose, the normal operation of all smart phone functions. But, when we use smart phone as company purpose like mobile information systems, the smart phone functions are blocked like screen capture, Wi-Fi, camera to protect company data. In this study, we suggest the design and implementation of real time control and management of mobile device using MDM(Mobile Device Management) solution. As a result, we can archive company security policy and individual using of smart phone and it is the optimal solution in the BYOD(Bring Your Own Device) era.

• Journal of radiological science and technology
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• v.38 no.3
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• pp.205-211
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• 2015

We evaluated the effectiveness of TL (Time Limit) method by comparing with NTL (Non-time limit) method when it is used for examinations for abdomen Anterior Posterior (AP) in this paper. The evaluation was conducted based on the comparison of dose, and of signal to noise ratio (SNR) and contrast to ratio (CNR) on both methods. The experiments were conducted with XGEO GC 80 (Samsung, Korea), Unfors ThinX RAD (Unfors, Sweden) and Rando Phantom (Alderson research laboratories, USA) and shielding material with the size of $5.5{\times}9{\times}0.1cm^3$. It was set to activate only two upper ionization chambers in automatic exposure control(AEC) mode and the tube-voltage was set to 80kVp. When the exposure time was limited, it is limited to 51 msec. The images both by NTL AEC method and TL AEC method were acquired when with and without attachment of shielding material on the upper ionization chambers. The images were evaluated by SNR and CNR which are the image evaluation methods using 'Image J'. The NTL AEC method showed increases in dose as much as 130.7% at maximum and 80% at minimum than other methods. The TL AEC method showed decreases in mAs and exposure dose than the NTL AEC method as much as 43.8% and 44.4% respectively. There were no significant differences in SNR or CNR for the experiments (($p{\geq}0.05$). Therefore, it is suggested that the TLAEC mode is more effective when examining patients who have high BMI index or a patient with a metallic substance in the body after surgery.

• Pediatric Infection and Vaccine
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• v.8 no.2
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• pp.213-221
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• 2001

Propose : Tsutsugamushi fever is a acute febrile disease, which is caused by O. tsutsugamushi. Recently, this disease is increasingly reported in children. This study was undertaken to investigate clinical features of tsutsugamushi fever in children. Methods : This study involved 17 children with tsutsugamushi fever who were admitted to Masan Samsung hospital between September 1997 and December 2000. We investigated the age, sex ratio, clinical manifestations, laboratory findings, response of therapy and prognosis. Results : The age of patients was $6.9{\pm}3.6$ years, ranging from 6 months to 12 years and male predilection(58.8%) was noted and all cases of patients occured in October or November. The most common symptoms were fever in all cases and headache in 8(47.1%). The most common signs were skin rash in all cases, eschar in 14(82.4%) and lymphadenopathy 8(47.1%). Locations of the eschars were back and inguinal area in each 3 cases, neck and chest in each 2, popliteal area in 2, scalp and thigh in each 1. Laboratory findings included anemia in 1 case, leukopenia and thrombocytopenia in each 5, hematuria and proteinuria in each 1, ESR elevation in 2 and positive CRP in 12, AST elevation in 9 and ALT elevation in 7. Serologic diagnosis was made by passive hemagglutination assay(PHA) in 8 cases(47%) on admission, 4 cases in initial negative group were performed follow-up test at 2nd or 3rd weeks of illness and then all cases of 4 were converted to positive reaction. Clinical improvement was noticed in all cases after treatment to chloramhenicol or doxycycline. Mean duration for defervescence after treatment was $1.4{\pm}0.8$ days. Complications were interstitial pneumonia in 1 case and aseptic meningitis in 3, but all cases of patients were recovered without sequelae or recurrence. Conclusions : Tsutsugamushi fever in children was similiar to adult in the clinical features except male predilection. Early diagnosis and empirical treatment based on clinical manifestations such as fever, skin rash, eschar, lymphadenopathy is important and serologic diagnosis need to perform follow-up test at 2nd or 3rd weeks of illness.

• Journal of Internet Computing and Services
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• v.13 no.2
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• pp.59-71
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• 2012

PKI-based public key scheme is outstanding in terms of authenticity and privacy. Nevertheless its application brings big burden due to the certificate/key management. It is difficult to apply it to limited computing devices in WSN because of its high encryption complexity. The Bilinear Pairing emerged from the original IBE to eliminate the certificate, is a future significant cryptosystem as based on the DDH(Decisional DH) algorithm which is significant in terms of computation and secure enough for authentication, as well as secure and faster. The practical EC Weil Pairing presents that its encryption algorithm is simple and it satisfies IND/NM security constraints against CCA. The Random Oracle Model based IBE PKG is appropriate to the structure of our target system with one secret file server in the operational perspective. Our work proposes modification of the Weil Pairing as proper to the closed network for secret file distribution[2]. First we proposed the improved one computing both encryption and message/user authentication as fast as O(DES) level, in which our scheme satisfies privacy, authenticity and integrity. Secondly as using the public key ID as effective as PKI, our improved IBE variant reduces the key exposure risk.

• Journal of the Korean Institute of Intelligent Systems
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• v.26 no.2
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• pp.113-119
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• 2016

Wireless sensor networks are vulnerable to an adversary due to scarce resources and wireless communication. An adversary can compromise a sensor node and launch a variety of attacks such as false report injection attacks. This attack may cause monetary damage resulting in energy drain by forwarding the false reports and false alarms at the base station. In order to address this problem, a number of en-route filtering schemes has been proposed. Notably, a dynamic en-route filtering scheme can save energy by filtering of the false report. In the key dissemination phase of the existing scheme, the nodes closer to the source node may not have matching keys to detect the false report. Therefore, continuous attacks may result in unnecessary energy wastage. In this paper, we propose a key re-distribution scheme to solve this issue. The proposed scheme early detects the false report injection attacks using initially assigned secret keys in the phase of the key pre-distribution. The experimental results demonstrate the validity of our scheme with energy efficiency of up to 26.63% and filtering capacity up to 15.92% as compared to the existing scheme.

• Journal of dental hygiene science
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• v.17 no.1
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• pp.46-55
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• 2017

Many people in Korea suffer from a fear of dental treatments; however, only a few studies have focused on this population. This study assessed the effectiveness of cognitive behavioral therapy (CBT) and its interventions in reducing dental anxiety, especially when administered by trained dental staff. Using case studies, the authors analyzed the content of each session and examined the process of reducing dental anxiety. First, the authors observed that the results of both dental fear scale and subjective unit of disturbance decreased significantly with changes in cognitive distortions related to dental anxiety and that rapid improvements were noted after two therapy sessions. Second, the study reported that practicing relaxation (deep-breathing) and muscle relaxation techniques; using hand signals to indicate anxiety or discomfort; establishing an empathic relationship with the therapist; making an anxiety list; and graded insensitive and exposure along with rehearsal, were effective in coping with dental anxiety and in changing negative thoughts towards the dentist. Third, a simple cognitive behavioral intervention can be effective in reducing dental anxiety. In summary, a short-term, five-session psychological intervention with CBT produced a sustained decrease in the symptoms of dental anxiety, allowing the patients to receive the required procedures. The authors discussed the study limitations and the implication of their results on future research.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.4
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• pp.505-511
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• 2010

Odontoma represents 22% of all odontogenic tumors, which is characterized by slow growth pattern. Most of the odontomas usually develop during dental follicle proliferation. The growth of odontoma is limited and lesion is generally asymptomatic. It is frequently diagnosed during assessments for delayed eruption of permanent tooth and is usually founded in the second decade of life. Odontoma is usually diagnosed through radiographic views and is difficult to diagnose at the early developmental stage of odontoma. But an uncalcified developing odontoma can disturb the eruption of the tooth, so it is important to perform periodic radiographic examinations. Treatments are surgical removal and observation of odontoma followed by surgical opening or orthodontic traction of impacted tooth according to the tooth development and the location of impacted tooth. In this case, we found the radiopaque calcified odontoma in the radiographic view meanwhile follow up of the impacted tooth showing idiopathic eruption disturbance. This suggests that a developing odontoma is the cause of eruption disturbace.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.194-199
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• 2006

쌍천유역의 강수량과 지하수위의 관계를 분석한 결과 융설효과를 확인하였고 갈수기에 지하수위가 현저히 저하됨을 확인하였다. 쌍천유역의 지하수위와 GOI의 상관관계를 분석한 결과 70일 이동평균값을 이용한 GOI가 가장 높은 상관관계를 보여주었다. 융설효과를 고려하기 위해서 먼저 유역의 DEM 자료를 이용하여 100m 간격으로 고도별 면적분포를 구하고 기온이 100m당 $0.5^{\circ}C$씩 감소하는 것을 고려하여 강수사상이 발생하면 $0^{\circ}C$ 이하가 되는 고도에서는 강설사상이 발생하는 것으로 가정하였다. 이 때 고도별 면적분포에서 구해지는 면적비를 고려하여 강수사상을 강우와 강설로 나누었다. 이후에 고도를 고려한 기온이 $0^{\circ}C$ 이상인 날에 그 고도의 설적이 모두 녹는 것으로 가정하였고 강우가 발생한 것으로 처리하였다. 유역평균 일최대침투량을 알아내기 위하여 강수량자료를 일정값 이상은 고정하여 수정된 강수량자료로 70일 이동평균값을 구하고 이 값들과 지하수위와의 상관관계를 분석해 본 결과 40mm가 일최대침투량으로 가정하였을 때 가장 높은 상관관계를 보여주었다. 쌍천유역의 경우 40mm가 한계침투량이다. 이렇게 수정된 강수자료를 이용하여 이동평균을 구하여 지하수위와의 상관관계를 구해본 결과 쌍천유역의 2003년부터 2005년까지 2개년 자료에 대해서 융설을 고려했을 때 상관관계가 더 높아짐을 알 수 있고 한계침투량을 고려했을 때도 상관관계가 더 높아짐을 알 수 있으며 융설효과와 한계침투량을 동시에 고려했을 경우에 가장 높은 상관관계를 얻을 수 있었다.$2.8g/cm^3$로 가정했을 때, 경상분지의 화강암류의 압력평균값이 약 $0.73{\sim}3.16kbar$의 범위를 가졌고, 경상분지내 백악기 화강암류의 정치 깊이는 $2.6{\sim}11.4km$범위를 가졌다. 이는 경상분지 화강암류에 대해 유추된 기존의 정성적인 생각과 일치한다는 것을 알 수 있었고, 각섬석의 $Al^T$함량을 이용한 여러 경험적, 실험적인 압력계가 많은 제한점이 있지만 경상분지의 백악기 불국사화강암류에는 정성적으로 유효함을 알 수 있었다. 우리는 최종적으로 경상분지내 백악기 화강암류는 천부관입 암체이고 노출된 화강암류가 천부지각이라는 것을 알 수 있었다. 것이 아니라 낙관적 예측을 수행하는 경향이 있음을 발견할 수 있었다.원밭, 화산회밭으로 6개 유형으로 분류할 경우 각각의 분포면적은 41.9%, 23.3%, 17.5%, 13.9%, 1.1. 2.2% 이었다. 도시화 및 도로확대 등 다양한 토지이용 및 지형개변으로 과거의 토양정보가 많이 변경되었다. 그래서, 앞으로는 인공위성자료 및 항공사진을 이용하여 빠르고 쉽게 활용할 수 있는 토양조사 방법개발과 기 구축된 토양도의 수정, 보완 작업이 필요한 절실히 요구되고 있는 현실이다.브로 출시에 따른 마케팅 및 고객관리와 관련된 시사점을 논의한다.는 교합면에서 2, 3, 4군이 1군에 비해 변연적합도가 높았으며 (p < 0.05), 인접면과 치은면에서는 군간 유의차를 보이지 않았다 이번 연구를 통하여 복합레진을 간헐적 광중합시킴으로써 변연적합도가 향상될 수 있음을 알 수 있었다.시장에 비해 주가가 비교적 안정적인

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.5
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• pp.534-540
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• 2013

Interest of the hand effect on the electromagnetic wave are internationally increasing with the increase of the use of the mobile phone. IEC TC106(International Electrotechnical Commission, Technical Committee 106) promotes international research exchange program in order to reflect the effect of human hands in the standard assessment method of human exposure dosimetry by the electromagnetic wave of mobile phones. Since current commercialized hand phantom is manufactured by taking into account the average size of westerners and provides only one grip posture, it imposes many restrictions on the accurate SAR measurement. Therefore, the development of proper hand phantom accounting for domestic situation and various grip posture capability is essential in order to analyze the accurate effect of human hand on the exposure estimation. In this paper, a jelly hand phantom suitable for Korean was manufactured with various grip posture capability at 835 MHz and 1,800 MHz bands. Although the tolerances of permittivity and conductivity of the manufactured hand phantom are with ${\pm}10%$ each, it was much less than CTIA(Cellular Telecommunication Industry Association) tolerance of ${\pm}20%$ at both bands. Its 3D CAD(3 Dimensional Computer Aided Design) file which was developed can be utilized for the simulation of human hand effect on SAR measurement of mobile phones. The findings in this study can be utilized for the analysis of human hand effect on SAR measurement of a mobile phone.