• Information Systems Review
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• v.11 no.1
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• pp.161-179
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• 2009

Nowadays an increasing number of Internet users are running individual websites as Blog or Cyworld. As this type of personal media has a great influence on communication among people, business comes to care about Network Effect, Network Software, and Social Network. For instance, Cyworld created the web service called 'Minihompy' for individual web-logs, and acquired 2.4milion users in 2007. Although many people assumed that the popularity of Minihompy, or Blog would be a passing fad, Cyworld has improved its service, and expanded its Network with various contents. This kind of expansion reflects survival efforts from infinite competitions among ISPs (Internet Service Provider) with focus on enhancing usability to users. However, Cyworld's Network Effect is gradually diminished in these days. Both of low production cost of service vendors and the low searching/conversing costs of users combine to make ISPs hard to keep their market share sustainable. To overcome this lackluster trend, Cyworld has adopted new strategies and try to lock their users in their service. Various efforts to improve the continuance and expansion of Network effect remain unclear and uncertain. If we understand beforehand how a service would improve Network effect, and which service could bring more effect, ISPs can get substantial help in launching their new business strategy. Regardless many diverse ideas to increase their user's duration online ISPs cannot guarantee 'how the new service strategies will end up in profitability. Therefore, this research studies about Network effect of Cyworld's 'Minihompy' using System-Dynamics method which could analyze dynamic relation between users and ISPs. Furthermore, the research aims to predict changes of Network Effect based on the strategy of new service. 'Page View' and 'Duration Time' can be enhanced for the short tenn because they enhance the service functionality. However, these services cannot increase the Network in the long-run. Limitations of this research include that we predict the future merely based on the limited data. We also limit the independent variables over Network Effect only to the following two issues: Increasing the number of users and increasing the Service Functionality. Despite of some limitations, this study perhaps gives some insights to the policy makers or others facing the stiff competition in the network business.

• The Korean Journal of Financial Management
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• v.12 no.2
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• pp.273-298
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• 1995

1960년대, 각국의 환율이 미국의 달러화에 연동(pegging)된 고정환율제도를 근간으로 하는 브레튼우즈(Bretton Woods)체제하에서 각국의 중앙은행은 환율을 일정한 범위 내로 유지하기 위한 정책수단으로 외환시장개입을 적극 활용하였다. 1973년 브레튼우즈체제하의 고정환율제도가 붕괴되고 변동환율제도가 채택된 이후에도 각국의 외환시장개입정책은 계속되었다. 1980년대에 레이건 행정부의 재정팽창정책과 미연방준비은행의 긴축통화정책으로 금리의 지속적인 상승과 미달러화의 큰폭의 절상이 이루어 졌다. 이에 국제무역의 위기를 우려한 미국, 독일, 프랑스, 영국, 일본 등 선진 5개국(Group-5, G5)은 1985년 9월 22일 미 달러화의 절하를 위해 외환시장에 공동으로 개입할 것을 주내용으로 한 플라자합의(Plaza Agreement)를 발표하였다. 그후에도 1987년 2월 23일 열린 루브르협정(Louvre Accord, G-6 Communique)에서 환율을 현수준으로 유지시키기 위한 목표환율대(Target zone)를 설정하고 외환시장개입을 통해 이를 유지하기로 합의한 바 있다. 이후의 구미각국은 환율의 관리를 위하여 국가가 공동으로 외환시장에 개입하곤 했다. 본 논문은 1987년 루브르협정 이후 미국, 독일 및 일본의 중앙은행의 외환시장 개입 정책이 소기의 목적을 달성했는지의 여부를 규명해 보고자 한다. 즉, Federal Reserve, Bundesbank 및 Bank of Japan의 외환시장개입이 현물환율시장(spot market)에서 각각의 변동성을 감소 시켰는지의 여부를 독일의 마르크화 및 일본의 엔화를 중심으로 규명해 보고자 한다. 1981년 루브르협정이후, 미국, 독일 및 일본의 중앙은행은 미국 달러화에 대한 마르크 및 엔화의 환율을 안정시키기 위해 꾸준히 외환시장에 개입해 왔다. 외환시장의 개입유형은 크게 태화외환시장개입(non-sterilized intervention)과 불태화외환시장개입(sterilized intervention)으로 구분할 수 있는데, 전자는 외환당국이 민간부문과 외화채권을 거래함으로써 본원통화의 크기가 변하는 개입형태를 의미하는 반면에 후자는 외환당국의 순외화자산의 크기변화가 본원통화의 변화를 초래하지 않는 경우이다. 즉, 불태화외환시장개입은 순외화자산의 증감이 순국내자산의 증감과 반비례해서 이루어지기 때문에 본원통화의 크기에는 변함이 없다. 외환시장개입이란 외환당국이 은행간 시장에서 민간시잔 참가자들과 행하는 적극적인 외환거래를 의미한다. 반면, 넓은 의미에서의 외환시장개입에는 수동적 외환시장개입이라고 불리는 고객거래가 포함된다. 후자의 거래는 국내통화 및 외화표시 자산의 상대적 공급규모를 변화시킨다는 의미에서 전통적외환시장개입과 동일한 효과를 갖기 때문에 광의의 외환시장 개입으로 분류된다. 외환시장의 개입목적은 크게 세 가지로 분류할 수 있다. 첫째, 환율의 안정적 운영이다. 환율수준이 자유롭게 변화되는 변동환율제도하에서 환율의 지나친 변동으로 인한 실물경제로의 부정적인 영향을 최소화하기 위해서 환율의 지나친 변동으로 인한 실물경제로의 부정적인 영향을 최소화하기 위해서 환율의 안정을 정책 목표로 설정하는 경우와 고정환율제도하에서 환율을 일정수준으로 유지시키기 위해서 외환당국이 외환시장에 개입하는 경우가 여기에 해당된다고 볼 수 있다. 둘째, 환율수준의 균형수준으로의 조정이다. 이때 야기될 수 있는 문제점으로는 환율균형 수준을 어떻게 정의, 추정할 것이냐 하는 점과 목표환율정책이 다른 정책목표와 상충될 수 있다는 점이다. 셋째, 외환당국이 공적외환보유액이나 구성을 변화시킬 목적으로 외환시장에 개입하는 경우이다. 이때의 외환시장개입은 현재의 환율수준이 개입으로 인하여 과도하게 이탈하는 문제가 발생하지 않을 것을 전제로 한다. 본고에서는 현물환율에 영향을 미치는 요소로 미국, 독일 및 일본의 중앙은행의 개입효과, 요일효과, 통화의 공급량(M1), 무역적자의 폭, 산업의 생산량, 생산가격지수(PPI), 소비자물가지수(CPI), 실업률, 옵션의 내재적 변동성 등을 고려한다. 환율의 변동성을 추정하는 식은 GARCH 모델이 사용된다. 본 추정모델은 Dominguez(1993)의 확장이다. Dominguez (1993)의 논문은 GARCH 모델을 써서 미국, 독일 및 일본의 중앙은행의 시장개입효과를 분석했으나, 거시변수를 고려대상에서 제외시켰다. 본 논문은 위의 방법에 거시변수를 삽입하고 모델을 변형시켜서 더 확실한 시장개입효과와 거시변수효과를 밝혔다. 또한 옵션의 내제적 변동성을 구하는 과정에서 American option model을 사용하는 대신, Bourtha & Courtadon (1987)등이 밝힌 바와 같이 American style option이라 할지라도, European Model을 쓰면 더욱더 간편하고, 예측력도 American Model에 뒤지지 않음을 이용하여, European Model을 써서 내재적 변동성을 구한 다음 이것을 독립변수로 이용하였다. 본 모델의 추정 결과는 3국의 시장개입정책이 현물환율과 옵션의 내재적 변동성을 증가시켜서 Louvre 협정이후 각국은 시장개입의 목적을 달성하지 못한 것으로 나타났다.

• Journal of Korean Society of Transportation
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• v.33 no.4
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• pp.379-392
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• 2015

Freight flow data in Korea has been collected for a variety of purposes by various organizations. However, since the representation and format of the data varies, it has not been substantially used for freight analyses and furthermore for freight policies. In order to increase the applicability of those data sets, it is required to bring them in a table and compare for finding the differences. Then, it is shown that the raw data can be aggregated by a particular criterion such as mode, origin and destination, and type commodity. This study aims to examine the freight data issue in terms of three different points of view. First, we investigated various freight volume data sets which are released by several organizations. Second, we tried to develop formulations for freight volume data. Third, we discussed how to apply the formulations to network models in which particular OR (Operations Research) techniques are used. The results emphasized that some data might be useless for modeling once they are aggregated. As a result of examining the freight volume data, this study found that 14 organizations share their data sets at various aggregation levels. This study is not an ordinary research article, which normally includes data analysis, because it seems to be impossible to conduct extensive case studies. The reason is that the data dealt in this study are diverse. Nevertheless, this study might guide the research direction in the freight transport research society in terms of data issue. Especially, it can be concluded that this study is a timely research because the governmemt has emphasized the importance of sharing data to public throughout 'government 3.0' for research purpose.

• Journal of Animal Science and Technology
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• v.48 no.2
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• pp.331-336
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• 2006

Moving behavior of groups of Hanwoo was observed when solid side was applied along the straight single file chute. Dark blue liners (PVC coated fabric) were hung on the outer side along the steel bars of chute to block vision of cattle. Ten animals were grouped together in a batch to move through chute to the restrainter. Movement of animals through chutes were significantly faster when solid side with liners were applied than when they had open vision of flight zone. And the difference in movement time between of solid side and open side was even greater in a longer chute than in a shorter one. From the experiment with longer chute, we could not find any significant differences between presence or absence of solid sides in the time spent for the leaading cattle to enter the squeeze chute from crowd pen. But the average time spent for movement from squeeze gait to restrainter was 22.78±1.15 seconds with solid sides, which was much shorter than with open sides (40.56±4.46 seconds). Time required for batch of animals to move from crowd pen to restrainter and exit was much faster with solid sides than with open sides: 96.33±3.98 seconds vs. 121.89±5.54 seconds from leading animal to enter the squeeze chute until the last animal of the batch to exit restrainter and 104.56±3.89 vs. 131.22±6.42 seconds for the whole batch of animals to enter the squeeze chute and exit restrainter. Another experiment with shorter chute showed that animals balked to right angled edge of the crowed pen before entering squeeze chute. We could not find any differences in time requred for the leading animal to enter the crowd pen from holding pen. Total time spent from entrance of leading animal to crowd pen until the last animal to exit restrainter was shorter with solid sides than with open sides: 177.44±5.20 seconds vs. 193.44±7.46 seconds.

• Tuberculosis and Respiratory Diseases
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• v.50 no.2
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• pp.222-228
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• 2001

Backgrounds : Recent technological developments have introduced a new method to identifying M. tuberculosis complex DNA in clinical samples directly. The direct amplification test (DAT) is approved for identifying M. tuberculosis complex in respiratory specimens that are smear-positive for acid-fast bacilli (AFB). When there is a discrepancy between the AFB smear and DAT, no information on their clinical utility is currently available. In this study, the diagnostic reliability of DAT was investigated in suspected pulmonary tuberculosis patients whose sputum AFB smear was negative. Methods : From June 1, 1998 through May 30, 1999, 909 patients with presumed active pulmonary tuberculosis were enrolled. A sputum AFB stain, culture, DAT and/or biopsy were performed. Using the criteria of clinical tuberculosis or confirmed tuberculosis, the positive predictive value of DAT in diagnosing pulmonary tuberculosis was investigated. Results : The positive predictive value of DAT was 82.1% by the clinically active tuberculosis criteria. However, it decreased to 61.5% when diagnosis was restricted to only to culture positive or biopsy proven cases. The false positive rate of DAT was 18.0%. Conclusion : The DAT is a valuable diagnostic method in suspected patients whose sputum AFB is was negative.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1972.03a
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• pp.7-8
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• 1972

The effects of noise exposure are of two types: Nonauditory effects and auditory effects. Nonauditory effects of noise exposure are interference with communication by speech, sleeping and emotional behavior. The noise will cause the high blood pressure and rapid pulse, also that decrease the salivation and gastric juice. in experimentaly showed that the Corticoid hormon: Gonatotropic hormone were decrease and Thyrotropic hormoone is increase. Auditory effect of noise exposure. when the normal ear is exposed to noise at noise at hamful intensities (above 90㏈) for sufficiently long periods of time, a temoral depression of hearing results, disappearing after minutes or hours of rest. When the exposure longer or intesity greater is reached the Permanent threshold shift called noise-induced hearing loss. Hearing loss resulting from noise exposure presents legal as well as medical problems. The otologist who examines and evaluates the industrial hearing loss cases must be properly informed, not only concerning the otologic but also about the physical and legal aspects of the problems. The measurement of hearing ability is the most important part of a hearing conservation, both preplacement and periodic follow-up tests of hearing. The ideal hearing conservation program would be able to reduce or eliminate the hazardous noise at its source or by acoustic isolation of noisy working area and two ear protections (plugs and muff type) were developed for personal protection.

• The Korean Journal of Air & Space Law and Policy
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• v.23 no.2
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• pp.115-136
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• 2008

The development of the aviation technology is beyond the people's imagination. For example, with some exaggeration, If the autopilot engage upon take off, You will realize that you are on the centerline of the foggy JFK runway 13R after 15 hours with only once or twice of intervention. But the more aviation technology develops, the more responsible the pilot will be who has the final authority of the aviation safety. In the JAL 706 accident caused by unidentified reason, the pilot increased pitch abruptly and overrode the control from the autopilot. The result of this process made the death of a flight attendant and some injuries of a few passengers. The district court found the pilot not guilty at the first trial on the ground that the control override was not connected to the possibility of foresight and avoidance of the human death. The pilot was proved to be innocent through the analysis of the DFDR and ADAS that the override did not precede the unidentified pitch up motion. The judicial precedent related to aviation accidents in Korea requires pilots' absolute and extended care compared to the ordinarily prudent or reasonably careful behaviors in the vehicle and medical accidents. Although there is some controversy about the standard care, the care required in the actual operation of high tech aircraft by a pilot should include objective and standard care and be judged by analysis of the scientific data. Although the pilot maintained the unusual hi speed that doesn't have safety margin and descended under turbulence in case of the JAL 706 accident, the court negatived its relation to the cause of pitch up. Also, the override of the control after initial pitch up might have caused the possibility of the death and injury, but the court denied it. Because of this complex cause of the aviation accidents, it is important for a court to figure out the core reason of the event and casual relationship with the pilot Now, It is required that the judgement of negligence in the aviation accidents should include an objective care with scientific data from simulated circumstances(or a simulator) as the Japanese court not from the theory of vehicle's negligence.

• Korea and Global Affairs
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• v.2 no.1
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• pp.69-92
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• 2018

North Korea conducted a total of six nuclear tests from the 1st test of 2006 to September, 2017. North Korea developed an armed forces security strategy at the level of regime protection and defense to respond to U.S. hostile policy. However, it is certain that strategic goals of North Korea's nuclear test were to overcome a crisis in North Korea's regime through US-North Korea negotiation and complete nuclear armed forces for socialist unification on the Korean Peninsula. North Korea's continuous nuclear test is a direct factor in threatening peace on the Korean Peninsula and an indirect factor in security dynamics of Northeast Asia. The U.N. Security Council has enforced sanctions against North Korea through six resolutions against North Korea's reckless nuclear test for the past 10 years. However, Kim Jong-Un's regime is in a position to stick to simultaneous pursuit of nuclear and economic development in spite of anti-North sanction of international society including U.N. and U.S.A. It is understood that North Korea was stimulated to conduct intense nuclear test as U.N. and U.S.A's anti-North sanction was not effective on North Korea. Full-scale and local wars are expected as military options, one of anti-North sanctions of the Trump administration. The Trump administration has attempted diplomatic pressure strategy as a secondary boycott unlike previous administrations. Nevertheless, North Korea has stood against U.N. and U.S.A's anti-North sanction with brinkmanship tactics, announcing full-scale military confrontation against U.S. It is judged that North Korea will pursue simultaneous nuclear weapons and economic development in terms of regime survival. North Korea will have less strategic choices in that its regime may collapse because of realistic national strategy between U.S.A. and China.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.6
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• pp.1407-1415
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• 2006

Japan started to colonize Korea in 1910. It's when It forced and made Chosun sign on the Treaty of Protectorate. The Chosun faithfully practiced Japan's colonial policy over Korea. Futhermore, it stopped many Koreans from an anti-Japanese movement and tried to make Koreans have a positive attitude towards Japan. For this, Japan advertised the policy called Nae-sun-il-che which meant Korea and Japan were a community together from the same root. Ultimately, it targeted on absorbing Korea within their territory. With this goal, Japan kept on practicing the policy to acculturize and brainwash Koreans, totally depending on force and pressure from 1910 to 1919. However, this policy had changed by the overall anti-Japanese movement happening on March 1st 1919. Saito, the third governor-general who was appointed laster on, made an effort to win over He favor of Koreans in a less forceful way of the cultural politics. The change of policy had been specified in diverse actions such as permitting civil mass-media bodies forming the observation groups and opening conferences. In the case of daily newspapers, Japan had permitted only the ones by the Government-General of Chosun such as Maeil-shinbo, Kyunsung-ilbo, and Seoul Press before, but then other civil newspapers In Korean stated to be released. Along His Japan formed both Korean and Japanese observation groups to promote the mutual understanding and showed off Japan's goods in the propaganda films by implementing a film department. It's because Japan totally recognized and understood the impact of films. Therefore, Japan distincitively established a film agency for the production of propaganda movies while it banned the civil film production after 1937 when Japan started the war against China and USA in row. So, only one film agency, ruled by the Government-General of Chosun, produced movies from 1942 to 1945.

• Journal of Legislation Research
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• no.44
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• pp.611-653
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• 2013

An whistle-blowing is recognition of acts of misconduct or corruption by individuals(laborers) or party which belongs to a certain organization and it refers to the act of informing to the senior organization or to the outside public agency to avoid jeopardies that could be potentially lead against benefit of the public. These whistle-blowings can be a Ansatz that improve corporation's transparency and accountability by prevention of enterprise's misconduct as well, it has been recognized as an important role for the establishment of corporate ethics, moreover, social justice. What to be treated primarily as labor law problem is arousing some controversies of the possibility that the public announcement could be whether a disciplinary punishment or not because it brings some mischievous effects for the honor and the reputation to the company which conducted the illegal actions and the action of the contrary to the social value. And futhermore, recently, the matter of compensational responsibility according to the arrangement conversion, bullying followed by the informant has been brought up. The fundamental standpoint of precedent related with the judgement of justification for the punishment as reason of the whistle-blowing ought to do the sincere duty for the labor contract which is the employees are supposed to consider the employer's profits. For that reason, if the emploee release the inside fact to the public and give any damages to employer's secret or confidence or honor, it will be a causing reasong of the disciplinary punishment, but in specific cases, the relevant and level of punishment limitation can be judged by the contents of public announcement and the truth, the purpose of the acts and details and the way of announcement. Precisely, on the assumption that there are necessity of the characteristic profit or the freedom of expression for the informant, with overall consideration whether or the basis part of the informant is true or there is a fair reason which make the informant believe is true or the purpose of informant has the public profit or the contents of the whistle-blowing are important for relevant organization or the means and the way was suitable, if the whistle-blowing are approved to be resonable, the organization are not permitted the reprimand or dismiss Futhermore, to find the solution for the issues of the disciplinary punishment and the treatment of all sorts of disadvantages, for the reason of whistle-blowing, since the protection law for public declarer which was enacted in last 2011 have the position as the general law, the purport of the equal law has to be considered sytematically and also the judicial precedent which is related to the justification of whistle-blowing are needed to be considered as well.